Autoclave treatment of the classical scrapie agent US No. 13-7 and experimental inoculation to susceptible VRQ/ARQ sheep via the oral route results in decreased transmission efficiency
PLoS One. 2020; 15(12): e0243009.
Published online 2020 Dec 3. doi: 10.1371/journal.pone.0243009
PMCID: PMC7714121
PMID: 33270721
Autoclave treatment of the classical scrapie agent US No. 13-7 and experimental inoculation to susceptible VRQ/ARQ sheep via the oral route results in decreased transmission efficiency
Eric D. Cassmann, Data curation, Formal analysis, Investigation, Writing – original draft, Writing – review & editing,# Najiba Mammadova, Data curation, Formal analysis, Investigation, Writing – original draft, Writing – review & editing,# and Justin J. Greenlee, Conceptualization, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, Writing – review & editing*
Byron Caughey, Editor
Abstract
Scrapie, a prion disease of sheep, is highly resistant to conventional deactivation. Numerous methods to deactivate scrapie have been tested in laboratory animal models, and adequate autoclave treatment can reduce or remove the infectivity of some classical scrapie strains depending on the heating parameters used. In this study, we autoclaved brain homogenate from a sheep with US scrapie strain 13–7 for 30 minutes at 121°C. Genetically susceptible VRQ/ARQ sheep were orally inoculated with 3 grams of the autoclaved brain homogenate. For comparison, a second group of sheep was inoculated with a non-autoclaved brain homogenate. Rectal biopsies were used to assess antemortem scrapie disease progression throughout the study. Five out of ten (5/10) sheep that received autoclaved inoculum ultimately developed scrapie after an experimental endpoint of 72 months. These sheep had a mean incubation period of 26.99 months. Two out of five (2/5) positive sheep had detectable PrPSc in antemortem rectal biopsies, and two (2/5) other sheep had PrPSc in postmortem rectal tissue. A single sheep (1/5) was positive for scrapie in the CNS, small intestine, and retropharyngeal lymph node but had negative rectal tissue. All of the sheep (10/10) that received non-autoclaved inoculum developed scrapie with a mean incubation period of 20.2 months and had positive rectal biopsies at the earliest timepoint (14.7 months post-inoculation). These results demonstrate that sheep are orally susceptible to US derived classical scrapie strain 13–7 after autoclave treatment at 121°C for 30 minutes. Differences in incubation periods and time interval to first positive rectal biopsies indicate a partial reduction in infectivity titers for the autoclaved inoculum group.
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We demonstrated that VRQ/ARQ genotype sheep are orally susceptible to 3 grams of brain homogenate containing classical scrapie prions that was autoclaved for 30 minutes at 121°C. At the experimental endpoint of 72 months post-inoculation, 50% (5/10) of the sheep that received autoclaved inoculum had succumbed to scrapie. Positive sheep had a prolonged incubation period compared to the non-autoclave inoculum group. Only 2/5 scrapie positive sheep had positive antemortem RAMALT biopsies from 23.5 months post-inoculation. In contrast, sheep that received non-autoclaved inoculum had positive RAMALT biopsies at the first timepoint, 14.7 months post-inoculation. Autoclave treatment resulted in a prolonged interval until the first positive rectal biopsy. This is presumably due to a lower infectious titer in the autoclaved inoculum. In summary, autoclave treatment of brain tissue from a symptomatic scrapie affected sheep was not sufficient to completely abate transmission under our experimental conditions.
*** Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery ***
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC.
Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892. Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8006664&dopt=Abstract
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC.
Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892. Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8006664&dopt=Abstract
http://web.archive.org/web/20090505235701/http://www.bseinquiry.gov.uk/files/yb/1981/11/26001001.pdf
WEDNESDAY, MAY 29, 2019
***> Incomplete inactivation of atypical scrapie following recommended autoclave decontamination procedures
USDA HERE'S YOUR SIGN!
Using in vitro Prion replication for high sensitive detection of prions and prionlike proteins and for understanding mechanisms of transmission.
Claudio Soto Mitchell Center for Alzheimer's diseases and related Brain disorders, Department of Neurology, University of Texas Medical School at Houston.
Prion and prion-like proteins are misfolded protein aggregates with the ability to selfpropagate to spread disease between cells, organs and in some cases across individuals. I n T r a n s m i s s i b l e s p o n g i f o r m encephalopathies (TSEs), prions are mostly composed by a misfolded form of the prion protein (PrPSc), which propagates by transmitting its misfolding to the normal prion protein (PrPC). The availability of a procedure to replicate prions in the laboratory may be important to study the mechanism of prion and prion-like spreading and to develop high sensitive detection of small quantities of misfolded proteins in biological fluids, tissues and environmental samples. Protein Misfolding Cyclic Amplification (PMCA) is a simple, fast and efficient methodology to mimic prion replication in the test tube. PMCA is a platform technology that may enable amplification of any prion-like misfolded protein aggregating through a seeding/nucleation process. In TSEs, PMCA is able to detect the equivalent of one single molecule of infectious PrPSc and propagate prions that maintain high infectivity, strain properties and species specificity. Using PMCA we have been able to detect PrPSc in blood and urine of experimentally infected animals and humans affected by vCJD with high sensitivity and specificity. Recently, we have expanded the principles of PMCA to amplify amyloid-beta (Aβ) and alphasynuclein (α-syn) aggregates implicated in Alzheimer's and Parkinson's diseases, respectively. Experiments are ongoing to study the utility of this technology to detect Aβ and α-syn aggregates in samples of CSF and blood from patients affected by these diseases.
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***>>> Recently, we have been using PMCA to study the role of environmental prion contamination on the horizontal spreading of TSEs. These experiments have focused on the study of the interaction of prions with plants and environmentally relevant surfaces. Our results show that plants (both leaves and roots) bind tightly to prions present in brain extracts and excreta (urine and feces) and retain even small quantities of PrPSc for long periods of time. Strikingly, ingestion of prioncontaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate. Furthermore, plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety of environmentally relevant surfaces, including stones, wood, metals, plastic, glass, cement, etc. Prion contaminated surfaces efficiently transmit prion disease when these materials were directly injected into the brain of animals and strikingly when the contaminated surfaces were just placed in the animal cage. These findings demonstrate that environmental materials can efficiently bind infectious prions and act as carriers of infectivity, suggesting that they may play an important role in the horizontal transmission of the disease.
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Since its invention 13 years ago, PMCA has helped to answer fundamental questions of prion propagation and has broad applications in research areas including the food industry, blood bank safety and human and veterinary disease diagnosis.
New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production
Detection of protease-resistant cervid prion protein in water from a CWD-endemic area
A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing
Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals
PPo4-4:
Survival and Limited Spread of TSE Infectivity after Burial
Discussion Classical scrapie is an environmentally transmissible disease because it has been reported in naïve, supposedly previously unexposed sheep placed in pastures formerly occupied by scrapie-infected sheep (4, 19, 20).
Although the vector for disease transmission is not known, soil is likely to be an important reservoir for prions (2) where – based on studies in rodents – prions can adhere to minerals as a biologically active form (21) and remain infectious for more than 2 years (22).
Similarly, chronic wasting disease (CWD) has re-occurred in mule deer housed in paddocks used by infected deer 2 years earlier, which was assumed to be through foraging and soil consumption (23).
Our study suggested that the risk of acquiring scrapie infection was greater through exposure to contaminated wooden, plastic, and metal surfaces via water or food troughs, fencing, and hurdles than through grazing.
Drinking from a water trough used by the scrapie flock was sufficient to cause infection in sheep in a clean building.
Exposure to fences and other objects used for rubbing also led to infection, which supported the hypothesis that skin may be a vector for disease transmission (9).
The risk of these objects to cause infection was further demonstrated when 87% of 23 sheep presented with PrPSc in lymphoid tissue after grazing on one of the paddocks, which contained metal hurdles, a metal lamb creep and a water trough in contact with the scrapie flock up to 8 weeks earlier, whereas no infection had been demonstrated previously in sheep grazing on this paddock, when equipped with new fencing and field furniture.
When the contaminated furniture and fencing were removed, the infection rate dropped significantly to 8% of 12 sheep, with soil of the paddock as the most likely source of infection caused by shedding of prions from the scrapie-infected sheep in this paddock up to a week earlier.
This study also indicated that the level of contamination of field furniture sufficient to cause infection was dependent on two factors: stage of incubation period and time of last use by scrapie-infected sheep.
Drinking from a water trough that had been used by scrapie sheep in the predominantly pre-clinical phase did not appear to cause infection, whereas infection was shown in sheep drinking from the water trough used by scrapie sheep in the later stage of the disease.
It is possible that contamination occurred through shedding of prions in saliva, which may have contaminated the surface of the water trough and subsequently the water when it was refilled.
Contamination appeared to be sufficient to cause infection only if the trough was in contact with sheep that included clinical cases.
Indeed, there is an increased risk of bodily fluid infectivity with disease progression in scrapie (24) and CWD (25) based on PrPSc detection by sPMCA.
Although ultraviolet light and heat under natural conditions do not inactivate prions (26), furniture in contact with the scrapie flock, which was assumed to be sufficiently contaminated to cause infection, did not act as vector for disease if not used for 18 months, which suggest that the weathering process alone was sufficient to inactivate prions.
PrPSc detection by sPMCA is increasingly used as a surrogate for infectivity measurements by bioassay in sheep or mice.
In this reported study, however, the levels of PrPSc present in the environment were below the limit of detection of the sPMCA method, yet were still sufficient to cause infection of in-contact animals.
In the present study, the outdoor objects were removed from the infected flock 8 weeks prior to sampling and were positive by sPMCA at very low levels (2 out of 37 reactions).
As this sPMCA assay also yielded 2 positive reactions out of 139 in samples from the scrapie-free farm, the sPMCA assay could not detect PrPSc on any of the objects above the background of the assay.
False positive reactions with sPMCA at a low frequency associated with de novo formation of infectious prions have been reported (27, 28).
This is in contrast to our previous study where we demonstrated that outdoor objects that had been in contact with the scrapie-infected flock up to 20 days prior to sampling harbored PrPSc that was detectable by sPMCA analysis [4 out of 15 reactions (12)] and was significantly more positive by the assay compared to analogous samples from the scrapie-free farm.
This discrepancy could be due to the use of a different sPMCA substrate between the studies that may alter the efficiency of amplification of the environmental PrPSc.
In addition, the present study had a longer timeframe between the objects being in contact with the infected flock and sampling, which may affect the levels of extractable PrPSc.
Alternatively, there may be potentially patchy contamination of this furniture with PrPSc, which may have been missed by swabbing.
The failure of sPMCA to detect CWD-associated PrP in saliva from clinically affected deer despite confirmation of infectivity in saliva-inoculated transgenic mice was associated with as yet unidentified inhibitors in saliva (29), and it is possible that the sensitivity of sPMCA is affected by other substances in the tested material.
In addition, sampling of amplifiable PrPSc and subsequent detection by sPMCA may be more difficult from furniture exposed to weather, which is supported by the observation that PrPSc was detected by sPMCA more frequently in indoor than outdoor furniture (12).
A recent experimental study has demonstrated that repeated cycles of drying and wetting of prion-contaminated soil, equivalent to what is expected under natural weathering conditions, could reduce PMCA amplification efficiency and extend the incubation period in hamsters inoculated with soil samples (30).
This seems to apply also to this study even though the reduction in infectivity was more dramatic in the sPMCA assays than in the sheep model.
Sheep were not kept until clinical end-point, which would have enabled us to compare incubation periods, but the lack of infection in sheep exposed to furniture that had not been in contact with scrapie sheep for a longer time period supports the hypothesis that prion degradation and subsequent loss of infectivity occurs even under natural conditions.
In conclusion, the results in the current study indicate that removal of furniture that had been in contact with scrapie-infected animals should be recommended, particularly since cleaning and decontamination may not effectively remove scrapie infectivity (31), even though infectivity declines considerably if the pasture and the field furniture have not been in contact with scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in furniture that was subjected to weathering, even though exposure led to infection in sheep, this method may not always be reliable in predicting the risk of scrapie infection through environmental contamination.
These results suggest that the VRQ/VRQ sheep model may be more sensitive than sPMCA for the detection of environmentally associated scrapie, and suggest that extremely low levels of scrapie contamination are able to cause infection in susceptible sheep genotypes.
Keywords: classical scrapie, prion, transmissible spongiform encephalopathy, sheep, field furniture, reservoir, serial protein misfolding cyclic amplification
2018 - 2019
***> This is very likely to have parallels with control efforts for CWD in cervids.
Rapid recontamination of a farm building occurs after attempted prion removal
Kevin Christopher Gough, BSc (Hons), PhD1, Claire Alison Baker, BSc (Hons)2, Steve Hawkins, MIBiol3, Hugh Simmons, BVSc, MRCVS, MBA, MA3, Timm Konold, DrMedVet, PhD, MRCVS3 and Ben Charles Maddison, BSc (Hons), PhD2
Abstract
The transmissible spongiform encephalopathy scrapie of sheep/goats and chronic wasting disease of cervids are associated with environmental reservoirs of infectivity.
Preventing environmental prions acting as a source of infectivity to healthy animals is of major concern to farms that have had outbreaks of scrapie and also to the health management of wild and farmed cervids.
Here, an efficient scrapie decontamination protocol was applied to a farm with high levels of environmental contamination with the scrapie agent.
Post-decontamination, no prion material was detected within samples taken from the farm buildings as determined using a sensitive in vitro replication assay (sPMCA).
A bioassay consisting of 25 newborn lambs of highly susceptible prion protein genotype VRQ/VRQ introduced into this decontaminated barn was carried out in addition to sampling and analysis of dust samples that were collected during the bioassay.
Twenty-four of the animals examined by immunohistochemical analysis of lymphatic tissues were scrapie-positive during the bioassay, samples of dust collected within the barn were positive by month 3.
The data illustrates the difficulty in decontaminating farm buildings from scrapie, and demonstrates the likely contribution of farm dust to the recontamination of these environments to levels that are capable of causing disease.
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As in the authors' previous study,12 the decontamination of this sheep barn was not effective at removing scrapie infectivity, and despite the extra measures brought into this study (more effective chemical treatment and removal of sources of dust) the overall rates of disease transmission mirror previous results on this farm. With such apparently effective decontamination (assuming that at least some sPMCA seeding ability is coincident with infectivity), how was infectivity able to persist within the environment and where does infectivity reside? Dust samples were collected in both the bioassay barn and also a barn subject to the same decontamination regime within the same farm (but remaining unoccupied). Within both of these barns dust had accumulated for three months that was able to seed sPMCA, indicating the accumulation of scrapie-containing material that was independent of the presence of sheep that may have been incubating and possibly shedding low amounts of infectivity.
This study clearly demonstrates the difficulty in removing scrapie infectivity from the farm environment. Practical and effective prion decontamination methods are still urgently required for decontamination of scrapie infectivity from farms that have had cases of scrapie and this is particularly relevant for scrapiepositive goatherds, which currently have limited genetic resistance to scrapie within commercial breeds.24 This is very likely to have parallels with control efforts for CWD in cervids.
Acknowledgements The authors thank the APHA farm staff, Tony Duarte, Olly Roberts and Margaret Newlands for preparation of the sheep pens and animal husbandry during the study. The authors also thank the APHA pathology team for RAMALT and postmortem examination.
Funding This study was funded by DEFRA within project SE1865.
Competing interests None declared.
Saturday, January 5, 2019
Rapid recontamination of a farm building occurs after attempted prion removal
THURSDAY, FEBRUARY 28, 2019
BSE infectivity survives burial for five years with only limited spread
***> CONGRESSIONAL ABSTRACTS PRION CONFERENCE 2018
P69 Experimental transmission of CWD from white-tailed deer to co-housed reindeer
Mitchell G (1), Walther I (1), Staskevicius A (1), Soutyrine A (1), Balachandran A (1)
(1) National & OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa, Ontario, Canada.
Chronic wasting disease (CWD) continues to be detected in wild and farmed cervid populations of North America, affecting predominantly white-tailed deer, mule deer and elk. Extensive herds of wild caribou exist in northern regions of Canada, although surveillance has not detected the presence of CWD in this population. Oral experimental transmission has demonstrated that reindeer, a species closely related to caribou, are susceptible to CWD. Recently, CWD was detected for the first time in Europe, in wild Norwegian reindeer, advancing the possibility that caribou in North America could also become infected. Given the potential overlap in habitat between wild CWD-infected cervids and wild caribou herds in Canada, we sought to investigate the horizontal transmissibility of CWD from white-tailed deer to reindeer.
Two white-tailed deer were orally inoculated with a brain homogenate prepared from a farmed Canadian white-tailed deer previously diagnosed with CWD. Two reindeer, with no history of exposure to CWD, were housed in the same enclosure as the white-tailed deer, 3.5 months after the deer were orally inoculated. The white-tailed deer developed clinical signs consistent with CWD beginning at 15.2 and 21 months post-inoculation (mpi), and were euthanized at 18.7 and 23.1 mpi, respectively. Confirmatory testing by immunohistochemistry (IHC) and western blot demonstrated widespread aggregates of pathological prion protein (PrPCWD) in the central nervous system and lymphoid tissues of both inoculated white-tailed deer. Both reindeer were subjected to recto-anal mucosal associated lymphoid tissue (RAMALT) biopsy at 20 months post-exposure (mpe) to the white-tailed deer. The biopsy from one reindeer contained PrPCWD confirmed by IHC. This reindeer displayed only subtle clinical evidence of disease prior to a rapid decline in condition requiring euthanasia at 22.5 mpe. Analysis of tissues from this reindeer by IHC revealed widespread PrPCWD deposition, predominantly in central nervous system and lymphoreticular tissues. Western blot molecular profiles were similar between both orally inoculated white-tailed deer and the CWD positive reindeer. Despite sharing the same enclosure, the other reindeer was RAMALT negative at 20 mpe, and PrPCWD was not detected in brainstem and lymphoid tissues following necropsy at 35 mpe. Sequencing of the prion protein gene from both reindeer revealed differences at several codons, which may have influenced susceptibility to infection.
Natural transmission of CWD occurs relatively efficiently amongst cervids, supporting the expanding geographic distribution of disease and the potential for transmission to previously naive populations. The efficient horizontal transmission of CWD from white-tailed deer to reindeer observed here highlights the potential for reindeer to become infected if exposed to other cervids or environments infected with CWD.
***> Infectious agent of sheep scrapie may persist in the environment for at least 16 years
***> Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded.
Gudmundur Georgsson,1 Sigurdur Sigurdarson2 and Paul Brown3
Correspondence
Gudmundur Georgsson ggeorgs@hi.is
1 Institute for Experimental Pathology, University of Iceland, Keldur v/vesturlandsveg, IS-112 Reykjavı´k, Iceland
2 Laboratory of the Chief Veterinary Officer, Keldur, Iceland
3 Bethesda, Maryland, USA
Received 7 March 2006 Accepted 6 August 2006
In 1978, a rigorous programme was implemented to stop the spread of, and subsequently eradicate, sheep scrapie in Iceland. Affected flocks were culled, premises were disinfected and, after 2–3 years, restocked with lambs from scrapie-free areas. Between 1978 and 2004, scrapie recurred on 33 farms. Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded. Of special interest was one farm with a small, completely self-contained flock where scrapie recurred 18 years after culling, 2 years after some lambs had been housed in an old sheephouse that had never been disinfected. Epidemiological investigation established with near certitude that the disease had not been introduced from the outside and it is concluded that the agent may have persisted in the old sheep-house for at least 16 years.
TITLE: PATHOLOGICAL FEATURES OF CHRONIC WASTING DISEASE IN REINDEER AND DEMONSTRATION OF HORIZONTAL TRANSMISSION
*** DECEMBER 2016 CDC EMERGING INFECTIOUS DISEASE JOURNAL CWD HORIZONTAL TRANSMISSION
SEE;
Back around 2000, 2001, or so, I was corresponding with officials abroad during the bse inquiry, passing info back and forth, and some officials from here inside USDA aphis FSIS et al. In fact helped me get into the USA 50 state emergency BSE conference call way back. That one was a doozy. But I always remember what “deep throat” I never knew who they were, but I never forgot;
Some unofficial information from a source on the inside looking out -
Confidential!!!!
As early as 1992-3 there had been long studies conducted on small pastures containing scrapie infected sheep at the sheep research station associated with the Neuropathogenesis Unit in Edinburgh, Scotland. Whether these are documented...I don't know. But personal recounts both heard and recorded in a daily journal indicate that leaving the pastures free and replacing the topsoil completely at least 2 feet of thickness each year for SEVEN years....and then when very clean (proven scrapie free) sheep were placed on these small pastures.... the new sheep also broke out with scrapie and passed it to offspring. I am not sure that TSE contaminated ground could ever be free of the agent!! A very frightening revelation!!!
---end personal email---end...tss
Infectivity surviving ashing to 600*C is (in my opinion) degradable but infective. based on Bown & Gajdusek, (1991), landfill and burial may be assumed to have a reduction factor of 98% (i.e. a factor of 50) over 3 years. CJD-infected brain-tissue remained infectious after storing at room-temperature for 22 months (Tateishi et al, 1988). Scrapie agent is known to remain viable after at least 30 months of desiccation (Wilson et al, 1950). and pastures that had been grazed by scrapie-infected sheep still appeared to be contaminated with scrapie agent three years after they were last occupied by sheep (Palsson, 1979).
Dr. Paul Brown Scrapie Soil Test BSE Inquiry Document
THURSDAY, FEBRUARY 28, 2019
BSE infectivity survives burial for five years with only limited spread
Efficient transmission of classical scrapie agent x124 by intralingual route to genetically susceptible sheep with a low dose inoculum
Highlights
The scrapie agent efficiently transmits after intralingual inoculation.
Oral lesions may increase the risk for scrapie transmission.
All sheep developed scrapie after intralingual inoculation with as little as 10 mg of infectious material.
Abstract
Scrapie is a naturally occurring prion disease of sheep and goats that results in accumulation of the misfolded prion protein (PrPSc) and progressive neurodegeneration. After inoculation with classical scrapie isolate x124, susceptibility and incubation period are associated with valine at codon 136 (V136) of the prion protein: VRQ/VRQ had the shortest incubation periods, followed by VRQ/ARQ sheep, while ARQ/ARQ sheep only developed disease after inoculation via the intracerebral route. Intralingual inoculation of TSE agents effectively transmits disease similar to intracranial inoculation; therefore, it is possible that oral lesions may facilitate susceptibility to scrapie transmission. In this study, investigated the infectivity of decreasing doses of the x124 scrapie agent (100 mg, 50 mg, 20 mg, and 10 mg) on incubation time and attack rate after experimental intralingual inoculation into VRQ/ARQ sheep. The lowest inoculum dose tested in this study effectively transmitted the x124 scrapie agent in VRQ/ARQ sheep with a 100% attack rate and no significant difference in incubation times among sheep inoculated with varying doses. Moreover, immunohistochemistry and western blot analysis revealed similar biochemical and immunohistochemical features among the four cohorts of sheep irrespective of inoculum dose. This study provides a starting point for further investigation to determine the minimum infectious dose of x124 scrapie in sheep and its effect on attack rate and incubation time, central for assessing the potential risk of scrapie occurrence in sheep flock.
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Our results indicate that the minimum dose of the x124 scrapie agent tested in this study (10 mg) was sufficient to cause disease, with a mean incubation time of 216.8 ± 13.1 days post inoculation(~1 month shorter than sheep inoculated with 100 mg and 50 mg of thex124 scrapie agent), and an overall attack rate of 100%. Additionally,immunohistochemistry and western blot analysis revealed similar immunohistological and biochemical features among the four cohorts of sheep irrespective of inoculum dose. This study utilizes the intralingual route of inoculation as an alternative to the intracranial route, that have been previously compared and these studies have been summarized in Table 2(Moore et al., 2016; Hamir et al., 2008). Generally, the IC route of inoculation of TSE agents results in the shortest time to clinical onset of disease in susceptible hosts, however this method has a higher risk of complications (e.g., CNS infections, intracranial hematoma, and anesthesia related complications), and requires close monitoring post inoculation. A study comparing intralingual and intracerebral administration of the x124 scrapie agent to genetically susceptible Suffolk sheep, demonstrated that the IL route of inoculation has an incubation time comparable to that of the IC method (Hamir et al., 2008)(Table 2).
The effect of varying scrapie inoculum doses on incubation times has been previously reported in two notable studies using mouse bioassay, specifically in an effort to determine whether there exists a threshold dose of scrapie agent below which the probability of infection is zero (McLean and Bostock, 2000; Fryer and McLean, 2011). In a comparative study, McLean and Bostock analyzed 117 titration experiments using seven distinct scrapie strains and ten different mouse breeds to determine attack rate and variance of incubation period a teach relative dose (McLean and Bostock, 2000). This study determined that on average with every tenfold increase in dose, the incubation period decreased by 25 days (McLean and Bostock, 2000). Fryer and McLean analyzed data from over four thousand mice inoculated at doses ranging over ten orders of magnitude, and refined the common perception that mean incubation times in TSEs decrease linearly with logarithmic decreases in inoculum dose (Fryer and McLean, 2011). While both of these reports provide evidence of a linear relationship between inoculum dose and incubation time in murine mouse models of scrapie, this study provides a starting point for further investigation of the effect of a low dose inoculum on incubation time and attack rate in large animal models of scrapie and natural scrapie hosts.
We take into consideration two caveats of this experiment, one being the limitation of the small sample size and another being that the minimum intralingual dose (10 mg) resulted in a 100% attack rate,giving rise to the consideration that lower doses may still be infectious while resulting in significantly longer incubation times. Further investigation is required to determine the minimum infectious dose of the x124 scrapie agent after intralingual inoculation. Additionally,since there appear to be least two distinct isolates of classical scrapie, x124 and No. 13–7, future work should include both strains in a comparative study to determine the minimum effective dose and the effect of dose on attack rate and survival time. Understanding the circumstances (e.g. route of infection and amount of inoculum) under which exposure to scrapie leads to infection is critical for managing risk to animal health.
MONDAY, JULY 13, 2020
Efficient transmission of classical scrapie agent x124 by intralingual route to genetically susceptible sheep with a low dose inoculum
PRION 2017 DECIPHERING NEURODEGENERATIVE DISORDERS
please see;
***Our transmission study demonstrates that CH 1641-like scrapie is likely to be more virulent than classical scrapie in cattle.
In the US, scrapie is reported primarily in sheep homozygous for 136A/171Q (AAQQ) and the disease phenotype is similar to that seen with experimental strain CH1641.
***Our transmission study demonstrates that CH 1641-like scrapie is likely to be more virulent than classical scrapie in cattle.
P-088 Transmission of experimental CH1641-like scrapie to bovine PrP overexpression mice
Kohtaro Miyazawa1, Kentaro Masujin1, Hiroyuki Okada1, Yuichi Matsuura1, Takashi Yokoyama2
1Influenza and Prion Disease Research Center, National Institute of Animal Health, NARO, Japan; 2Department of Planning and General Administration, National Institute of Animal Health, NARO
Introduction: Scrapie is a prion disease in sheep and goats. CH1641-lke scrapie is characterized by a lower molecular mass of the unglycosylated form of abnormal prion protein (PrpSc) compared to that of classical scrapie. It is worthy of attention because of the biochemical similarities of the Prpsc from CH1641-like and BSE affected sheep. We have reported that experimental CH1641-like scrapie is transmissible to bovine PrP overexpression (TgBoPrP) mice (Yokoyama et al. 2010). We report here the further details of this transmission study and compare the biological and biochemical properties to those of classical scrapie affected TgBoPrP mice.
Methods: The details of sheep brain homogenates used in this study are described in our previous report (Yokoyama et al. 2010). TgBoPrP mice were intracerebrally inoculated with a 10% brain homogenate of each scrapie strain. The brains of mice were subjected to histopathological and biochemical analyses.
Results: Prpsc banding pattern of CH1641-like scrapie affected TgBoPrP mice was similar to that of classical scrapie affected mice. Mean survival period of CH1641-like scrapie affected TgBoPrP mice was 170 days at the 3rd passage and it was significantly shorter than that of classical scrapie affected mice (439 days). Lesion profiles and Prpsc distributions in the brains also differed between CH1641-like and classical scrapie affected mice.
Conclusion: We succeeded in stable transmission of CH1641-like scrapie to TgBoPrP mice. Our transmission study demonstrates that CH 1641-like scrapie is likely to be more virulent than classical scrapie in cattle.
snip...
In the US, scrapie is reported primarily in sheep homozygous for 136A/171Q (AAQQ) and the disease phenotype is similar to that seen with experimental strain CH1641.
snip...see ;
March 2019
Pennsylvania Scrapie Infected Sheep Goat Flock
TUESDAY, MARCH 31, 2020
The Scrapie Prevalence in a Goat Herd Is Underestimated by Using a Rapid Diagnostic Test
TUESDAY, JUNE 30, 2020
National Scrapie Eradication Program May 2020 Monthly Report Fiscal Year 2020 U.S. Department of Agriculture Animal and Plant Health Inspection Service Veterinary Services Strategy and Policy, Ruminant Health Center Small Ruminant Health June 15, 2020
April 22, 2016
Scrapie Confirmed in a Hartley County Sheep
AUSTIN – Texas Animal Health Commission (TAHC) officials have confirmed scrapie in a Hartley County ewe. The ewe was tested by TAHC after the owner reported signs of weight loss and lack of coordination to their local veterinarian. The premises was quarantined and a flock plan for monitoring is being developed by the TAHC and USDA.
“The TAHC is working closely with the flock owner, sharing all of the options for disease eradication,” said Dr. David Finch, TAHC Region 1 Director. “We are thankful the producer was proactive in identifying a problem and seeking veterinary help immediately.”
Texas leads the nation in sheep and goat production. Since 2008, there have been no confirmed cases of scrapie in Texas. The last big spike in Texas scrapie cases was in 2006 when nine infected herds were identified and the last herd was released from restrictions in 2013.
According to USDA regulations, Texas must conduct adequate scrapie surveillance by collecting a minimum of 598 sheep samples annually. Since USDA slaughter surveillance started in FY 2003, the percent of cull sheep found positive for scrapie at slaughter (once adjusted for face color) has decreased 90 percent.
Scrapie is the oldest known transmissible spongiform encephalopathies, and under natural conditions only sheep and goats are known to be affected by scrapie. It is a fatal disease that affects the central nervous system of sheep and goats. It is not completely understood how scrapie is passed from one animal to the next and apparently healthy sheep infected with scrapie can spread the disease. Sheep and goats are typically infected as young lambs or kids, though adult sheep and goats can become infected.
The most effective method of scrapie prevention is to maintain a closed flock. Raising replacement ewes, purchasing genetically resistant rams and ewes, or buying from a certified-free scrapie flock are other options to reduce the risk of scrapie. At this time the resistant genetic markers in goats have not been identified, therefore it is important to maintain your sheep and goat herds separately.
The incubation period for Scrapie is typically two to five years. Producers should record individual identification numbers and the seller’s premise identification number on purchase and sales records. These records must be maintained for a minimum of five years.
Producers should notify the Texas Animal Health Commission (800-550-8242) or the USDA-Austin Office (512-383-2400) if they have an adult sheep or goat with neurologic signs such as incoordination, behavioral changes, or intense itching with wool loss. Producers may order scrapie identification tags by calling 866-873-2824.
For more information, please visit our website at: http://www.tahc.texas.gov/animal_health/scrapie/scrapie.html. ;
###
***> Infectious agent of sheep scrapie may persist in the environment for at least 16 years
***> Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded.
Gudmundur Georgsson,1 Sigurdur Sigurdarson2 and Paul Brown3
Correspondence
Gudmundur Georgsson ggeorgs@hi.is
1 Institute for Experimental Pathology, University of Iceland, Keldur v/vesturlandsveg, IS-112 Reykjavı´k, Iceland
2 Laboratory of the Chief Veterinary Officer, Keldur, Iceland
3 Bethesda, Maryland, USA
Received 7 March 2006 Accepted 6 August 2006
In 1978, a rigorous programme was implemented to stop the spread of, and subsequently eradicate, sheep scrapie in Iceland. Affected flocks were culled, premises were disinfected and, after 2–3 years, restocked with lambs from scrapie-free areas. Between 1978 and 2004, scrapie recurred on 33 farms. Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded. Of special interest was one farm with a small, completely self-contained flock where scrapie recurred 18 years after culling, 2 years after some lambs had been housed in an old sheephouse that had never been disinfected. Epidemiological investigation established with near certitude that the disease had not been introduced from the outside and it is concluded that the agent may have persisted in the old sheep-house for at least 16 years.
WHY NOT SHOW A DETAILED MAP OF ATYPICAL NOR98-like Scrapie $$$
WHAT could some ramifications be from purposely omitting ATYPICAL NOR98-LIKE SCRAPIE???
Tuesday, June 3, 2008
SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PA
http://nor-98.blogspot.com/2008/06/scrapie-usa-update-june-2008-nor-98.html
SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PA
http://nor-98.blogspot.com/2008/06/scrapie-usa-update-june-2008-nor-98.html
Case 6
The sixth case of Nor98 scrapie was identified in a 4-year-old, white-faced ewe that was purchased and added to a commercial flock in Pennsylvania that consisted of approximately 700 head of sheep and goats. Individual animal records were not kept on the premises, so it was impossible to determine exactly how long the ewe was on the farm or her flock of origin. It was estimated that she remained in this flock for approximately 1 month, was sent to slaughter, and was tested for PrPSc as part of the RSSS program. No clinical signs suggestive of scrapie disease were noted. The Prnp genotype of the case 6 ewe was AFRQ/ALRQ (136 AA, 141 FL, 154 RR, 171 QQ). Evaluation of the brain by using HE revealed no lesions. IHC highlighted PrPSc bilaterally in the spinal nucleus of the trigeminal nerve (Fig. 1H) and in the dorsal aspect of the dorsal horns of the cervical spinal cord. PrPSc immunolabeling in the dorsal motor nucleus of the vagus nerve and in lymphoid tissue was absent. Cerebellum was unavailable for evaluation. ELISA and Western blot tests were not done because fresh tissue was unavailable. The commercial flock was depopulated, and adult animals exposed to this ewe were tested for scrapie. No additional cases of Nor98 or classic scrapie were identified. A summary of relevant findings from all cases is shown in Table 1.
THURSDAY, DECEMBER 19, 2019
The emergence of classical BSE from atypical/Nor98 scrapie
Monday, November 30, 2009
USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE
Thursday, December 20, 2012
*** OIE GROUP RECOMMENDS THAT SCRAPE PRION DISEASE BE DELISTED, WISHES TO CONTINUE SPREADING IT AROUND THE GLOBE
This surveillance plan is designed to speed the eradication of classical scrapie. Cases of nonclassical (Nor98-like) scrapie will be found because of testing for classical scrapie but the plan is not designed to maximize these detections. Nor98-like scrapie has its own unique characteristics, and the Animal and Plant Health Inspection Service (APHIS) and the OIE have concluded that it is “clinically, pathologically, biochemically, and epidemiologically unrelated to classical scrapie, may not be contagious and may, in fact, be a spontaneous degenerative condition of older sheep.” As a result, APHIS does not restrict or depopulate animals exposed to Nor98-like scrapie.
***> As a result, APHIS does not restrict or depopulate animals exposed to Nor98-like scrapie.
incredible stupidity, not based on sound science...
WEDNESDAY, MAY 29, 2019
Incomplete inactivation of atypical scrapie following recommended autoclave decontamination procedures USDA HERE'S YOUR SIGN!
***> Thus, atypical scrapie is recognized as a separate, nonreportable disease by the World Organization for Animal Health (OIE).
''as usual, OIE USDA et al put cart before horse, and put human and animal life at risk...terry''
Atypical scrapie has been transmitted experimentally to AHQ sheep by the intracranial145 and oral146 routes. An increased risk of atypical scrapie has also been identified in sheep with the AF141RQ haplotype.137 Atypical scrapie does experimentally transmit to sheep with the AL141RQ haplotype but with very long incubation periods without clinical signs.123 Furthermore, sheep with the ARR haplotype, which confers resistance to classical scrapie and is the cornerstone of genotype-based eradication programs, do not appear to be protected against developing atypical scrapie.41,137
Atypical scrapie has also been reported in goats,103,142 where the molecular profile on western blot is similar to atypical scrapie in sheep, but the distribution of lesions within the brain is more rostral (thalamus and midbrain) than atypical scrapie of sheep.142 Similar to sheep with atypical scrapie, histidine substitution at PRNP codon 154 is a risk factor for atypical scrapie in goats,32 and PrPSc has not been demonstrated in the lymphoid tissues of affected goats.142
end...see;
A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes
Annick Le Dur*,?, Vincent Béringue*,?, Olivier Andréoletti?, Fabienne Reine*, Thanh Lan Laï*, Thierry Baron§, Bjørn Bratberg¶, Jean-Luc Vilotte?, Pierre Sarradin**, Sylvie L. Benestad¶, and Hubert Laude*,?? +Author Affiliations
*Virologie Immunologie Moléculaires and ?Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; ?Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; §Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway
***Edited by Stanley B. Prusiner, University of California, San Francisco, CA (received for review March 21, 2005)
Abstract
Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice.
*** These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
OR
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
OR
*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.
OR here;
*** The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.
VARIABLY PROTEASE-SENSITVE PRIONOPATHY IS TRANSMISSIBLE ...price of prion poker goes up again $
OR-10: Variably protease-sensitive prionopathy is transmissible in bank voles
Romolo Nonno,1 Michele Di Bari,1 Laura Pirisinu,1 Claudia D’Agostino,1 Stefano Marcon,1 Geraldina Riccardi,1 Gabriele Vaccari,1 Piero Parchi,2 Wenquan Zou,3 Pierluigi Gambetti,3 Umberto Agrimi1 1Istituto Superiore di Sanità; Rome, Italy; 2Dipartimento di Scienze Neurologiche, Università di Bologna; Bologna, Italy; 3Case Western Reserve University; Cleveland, OH USA
Background. Variably protease-sensitive prionopathy (VPSPr) is a recently described “sporadic”neurodegenerative disease involving prion protein aggregation, which has clinical similarities with non-Alzheimer dementias, such as fronto-temporal dementia. Currently, 30 cases of VPSPr have been reported in Europe and USA, of which 19 cases were homozygous for valine at codon 129 of the prion protein (VV), 8 were MV and 3 were MM. A distinctive feature of VPSPr is the electrophoretic pattern of PrPSc after digestion with proteinase K (PK). After PK-treatment, PrP from VPSPr forms a ladder-like electrophoretic pattern similar to that described in GSS cases. The clinical and pathological features of VPSPr raised the question of the correct classification of VPSPr among prion diseases or other forms of neurodegenerative disorders. Here we report preliminary data on the transmissibility and pathological features of VPSPr cases in bank voles.
Materials and Methods. Seven VPSPr cases were inoculated in two genetic lines of bank voles, carrying either methionine or isoleucine at codon 109 of the prion protein (named BvM109 and BvI109, respectively). Among the VPSPr cases selected, 2 were VV at PrP codon 129, 3 were MV and 2 were MM. Clinical diagnosis in voles was confirmed by brain pathological assessment and western blot for PK-resistant PrPSc (PrPres) with mAbs SAF32, SAF84, 12B2 and 9A2.
Results. To date, 2 VPSPr cases (1 MV and 1 MM) gave positive transmission in BvM109. Overall, 3 voles were positive with survival time between 290 and 588 d post inoculation (d.p.i.). All positive voles accumulated PrPres in the form of the typical PrP27–30, which was indistinguishable to that previously observed in BvM109 inoculated with sCJDMM1 cases.
In BvI109, 3 VPSPr cases (2 VV and 1 MM) showed positive transmission until now. Overall, 5 voles were positive with survival time between 281 and 596 d.p.i.. In contrast to what observed in BvM109, all BvI109 showed a GSS-like PrPSc electrophoretic pattern, characterized by low molecular weight PrPres. These PrPres fragments were positive with mAb 9A2 and 12B2, while being negative with SAF32 and SAF84, suggesting that they are cleaved at both the C-terminus and the N-terminus. Second passages are in progress from these first successful transmissions.
Conclusions. Preliminary results from transmission studies in bank voles strongly support the notion that VPSPr is a transmissible prion disease. Interestingly, VPSPr undergoes divergent evolution in the two genetic lines of voles, with sCJD-like features in BvM109 and GSS-like properties in BvI109.
The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.
P.97: Scrapie transmits to white-tailed deer by the oral route and has a molecular profile similar to chronic wasting disease and distinct from the scrapie inoculum
Justin Greenlee1, S JO Moore1, Jodi Smith1, M Heather WestGreenlee2 and Robert Kunkle1
1National Animal Disease Center; Ames, IA USA
2Iowa State University; Ames, IA USA
The purpose of this work was to determine susceptibility of white-tailed deer (WTD) to the agent of sheep scrapie and to compare the resultant PrPSc to that of the original inoculum and chronic wasting disease (CWD). We inoculated WTD by a natural route of exposure (concurrent oral and intranasal (IN); n = 5) with a US scrapie isolate. All scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues at preclinical time points, and deer necropsied after 28 months post-inoculation had clinical signs, spongiform encephalopathy, and widespread distribution of PrPSc in neural and lymphoid tissues. Western blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral cortex had a profile similar to the original scrapie inoculum, whereas WB of brainstem, cerebellum, or lymph nodes revealed PrPSc with a higher profile resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical scrapie were further passaged to mice expressing cervid prion protein and intranasally to sheep and WTD. In cervidized mice, the 2 inocula have distinct incubation times. Sheep inoculated intranasally with WTD derived scrapie developed disease, but only after inoculation with the inoculum that had a scrapie-like profile. The WTD study is ongoing, but deer in both inoculation groups are positive for PrPSc by rectal mucosal biopsy.
***In summary, this work demonstrates that WTD are susceptible to the agent of scrapie, 2 distinct molecular profiles of PrPSc are present in the tissues of affected deer, and inoculum of either profile readily passes to deer.
*** After a natural route of exposure, 100% of WTD were susceptible to scrapie.
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
White-tailed deer are susceptible to the agent of sheep scrapie by intracerebral inoculation
snip...
It is unlikely that CWD will be eradicated from free-ranging cervids, and the disease is likely to continue to spread geographically [10]. However, the potential that white-tailed deer may be susceptible to sheep scrapie by a natural route presents an additional confounding factor to halting the spread of CWD. This leads to the additional speculations that
1) infected deer could serve as a reservoir to infect sheep with scrapie offering challenges to scrapie eradication efforts and
2) CWD spread need not remain geographically confined to current endemic areas, but could occur anywhere that sheep with scrapie and susceptible cervids cohabitate.
This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by intracerebral inoculation with a high attack rate and that the disease that results has similarities to CWD. These experiments will be repeated with a more natural route of inoculation to determine the likelihood of the potential transmission of sheep scrapie to white-tailed deer. If scrapie were to occur in white-tailed deer, results of this study indicate that it would be detected as a TSE, but may be difficult to differentiate from CWD without in-depth biochemical analysis.
2012
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
snip...
The results of this study suggest that there are many similarities in the manifestation of CWD and scrapie in WTD after IC inoculation including early and widespread presence of PrPSc in lymphoid tissues, clinical signs of depression and weight loss progressing to wasting, and an incubation time of 21-23 months. Moreover, western blots (WB) done on brain material from the obex region have a molecular profile similar to CWD and distinct from tissues of the cerebrum or the scrapie inoculum. However, results of microscopic and IHC examination indicate that there are differences between the lesions expected in CWD and those that occur in deer with scrapie: amyloid plaques were not noted in any sections of brain examined from these deer and the pattern of immunoreactivity by IHC was diffuse rather than plaque-like.
*** After a natural route of exposure, 100% of WTD were susceptible to scrapie.
Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer exhibited two different molecular profiles: samples from obex resembled CWD whereas those from cerebrum were similar to the original scrapie inoculum. On further examination by WB using a panel of antibodies, the tissues from deer with scrapie exhibit properties differing from tissues either from sheep with scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are strongly immunoreactive when probed with mAb P4, however, samples from WTD with scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4 or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly immunoreactive and samples from WTD with scrapie are strongly positive. This work demonstrates that WTD are highly susceptible to sheep scrapie, but on first passage, scrapie in WTD is differentiable from CWD.
2011
*** After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie.
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
snip.....
In the USA, under the Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law.
Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
snip.....
36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011).
The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE).
Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison.
snip.....
The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
snip.....
In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion.
snip.....
In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible... For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
snip.....
Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
snip.....
TUESDAY, APRIL 18, 2017
*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
***> Wednesday, January 23, 2019
***> CFIA SFCR Guidance on Specified risk material (SRM) came into force on January 15, 2019 <***
Prion Conference 2018
O5 Prion Disease in Dromedary Camels
Babelhadj B (1), Di Bari MA (2), Pirisinu L (2), Chiappini B (2), Gaouar SB (3), Riccardi G (2), Marcon S (2), Agrimi U (2), Nonno R (2), Vaccari G (2) (1) École Normale Supérieure Ouargla. Laboratoire de protection des écosystèmes en zones arides et semi arides University Kasdi Merbah Ouargla, Ouargla, Algeria; (2) Istituto Superiore di Sanità, Department of Food Safety, Nutrition and Veterinary Public Health, Rome, Italy (3) University Abou Bekr Bélkaid, Tlemcen, Algeria.
Prions are responsible for fatal and transmissible neurodegenerative diseases including CreutzfeldtJakob disease in humans, scrapie in small ruminants and bovine spongiform encephalopathy (BSE). Following the BSE epidemic and the demonstration of its zoonotic potential, general concerns have been raised on animal prions.
Here we report the identification of a prion disease in dromedary camels (Camelus dromedarius) in Algeria and designate it as Camel Prion Disease (CPD). In the last years, neurological symptoms have been observed in adult male and female dromedaries presented for slaughter at the Ouargla abattoir. The symptoms include weight loss, behavioral abnormalities and neurological symptoms such as tremors, aggressiveness, hyper-reactivity, typical down and upwards movements of the head, hesitant and uncertain gait, ataxia of the hind limbs, occasional falls and difficult getting up. During 2015 and 2016, symptoms suggestive of prion disease were observed in 3.1% of 2259 dromedaries presented at ante-mortem examination. Laboratory diagnosis was obtained in three symptomatic dromedaries, sampled in 2016 and 2017, by the detection of typical neurodegeneration and disease-specific prion protein (PrPSc) in brain tissues.
Histopathological examination revealed spongiform change, gliosis and neuronal loss preferentially in grey matter of subcortical brain areas. Abundant PrPSc deposition was detected in the same brain areas by immunohistochemistry and PET-blot. Western blot analysis confirmed the presence of PK-resistant PrPSc, whose N-terminal cleaved PK-resistant core was characterized by a mono-glycosylated dominant form and by a distinctive N-terminal cleavage, different from that observed in BSE and scrapie.
PrPSc was also detected, by immunohistochemistry, in all sampled lymph nodes (cervical, prescapular and lumbar aortic) of the only animal from which they were collected.
The PRNP sequence of the two animals for which frozen material was available, showed 100% nucleotide identity with the PRNP sequence already reported for dromedary camel.
Overall, these data demonstrate the presence of a prion disease in dromedary camelswhose nature, origin and spread need further investigations. However, our preliminary observations on the rather high prevalence of symptomatic dromedaries and the involvement of lymphoid tissues, are consistent with CPD being an infectious disease. In conclusion, the emergence of a new prion disease in a livestock species of crucial importance for millions of people around the world, makes urgent to assess the risk for humans and to develop policies able to control the spread of the disease in animals and to minimize human exposure.
CDC
New Outbreak of TSE Prion in NEW LIVESTOCK SPECIES
Mad Camel Disease
Volume 24, Number 6—June 2018 Research
Prion Disease in Dromedary Camels, Algeria
Abstract
Prions cause fatal and transmissible neurodegenerative diseases, including Creutzfeldt-Jakob disease in humans, scrapie in small ruminants, and bovine spongiform encephalopathy (BSE). After the BSE epidemic, and the associated human infections, began in 1996 in the United Kingdom, general concerns have been raised about animal prions. We detected a prion disease in dromedary camels (Camelus dromedarius) in Algeria. Symptoms suggesting prion disease occurred in 3.1% of dromedaries brought for slaughter to the Ouargla abattoir in 2015–2016. We confirmed diagnosis by detecting pathognomonic neurodegeneration and disease-specific prion protein (PrPSc) in brain tissues from 3 symptomatic animals. Prion detection in lymphoid tissues is suggestive of the infectious nature of the disease. PrPSc biochemical characterization showed differences with BSE and scrapie. Our identification of this prion disease in a geographically widespread livestock species requires urgent enforcement of surveillance and assessment of the potential risks to human and animal health.
SNIP...
The possibility that dromedaries acquired the disease from eating prion-contaminated waste needs to be considered.
Tracing the origin of prion diseases is challenging. In the case of CPD, the traditional extensive and nomadic herding practices of dromedaries represent a formidable factor for accelerating the spread of the disease at long distances, making the path of its diffusion difficult to determine. Finally, the major import flows of live animals to Algeria from Niger, Mali, and Mauritania (27) should be investigated to trace the possible origin of CPD from other countries.
Camels are a vital animal species for millions of persons globally. The world camel population has a yearly growth rate of 2.1% (28). In 2014, the population was estimated at ≈28 million animals, but this number is probably underestimated.. Approximately 88% of camels are found in Africa, especially eastern Africa, and 12% are found in Asia. Official data reported 350,000 dromedaries in Algeria in 2014 (28).
On the basis of phenotypic traits and sociogeographic criteria, several dromedary populations have been suggested to exist in Algeria (29). However, recent genetic studies in Algeria and Egypt point to a weak differentiation of the dromedary population as a consequence of historical use as a cross-continental beast of burden along trans-Saharan caravan routes, coupled with traditional extensive/nomadic herding practices (30).
Such genetic homogeneity also might be reflected in PRNP. Studies on PRNP variability in camels are therefore warranted to explore the existence of genotypes resistant to CPD, which could represent an important tool for CPD management as it was for breeding programs for scrapie eradication in sheep.
In the past 10 years, the camel farming system has changed rapidly, with increasing setup of periurban dairy farms and dairy plants and diversification of camel products and market penetration (13). This evolution requires improved health standards for infectious diseases and, in light of CPD, for prion diseases.
The emergence of another prion disease in an animal species of crucial importance for millions of persons worldwide makes it necessary to assess the risk for humans and develop evidence-based policies to control and limit the spread of the disease in animals and minimize human exposure. The implementation of a surveillance system for prion diseases would be a first step to enable disease control and minimize human and animal exposure. Finally, the diagnostic capacity of prion diseases needs to be improved in all countries in Africa where dromedaries are part of the domestic livestock.
***> IMPORTS AND EXPORTS <***
***SEE MASSIVE AMOUNTS OF BANNED ANIMAL PROTEIN AKA MAD COW FEED IN COMMERCE USA DECADES AFTER POST BAN ***
ZOONOSIS OF SCRAPIE TSE PRION
O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases.
We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
==============
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a. Vincent Beringue c. Patricia Aguilar a,
Natalia Fernandez-Borges a. and Alba Marin-Moreno a
"Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos, Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT. Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas. France
Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD) disease in human. To date, BSE agent is the only recognized zoonotic prion... Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that have been circulating for centuries in farmed ruminants there is no apparent epidemiological link between exposure to ruminant products and the occurrence of other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD). However, the zoonotic potential of the diversity of circulating TSE agents has never been systematically assessed. The major issue in experimental assessment of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the biological phenomenon that limits TSE agents’ propagation from a species to another. In the last decade, mice genetically engineered to express normal forms of the human prion protein has proved essential in studying human prions pathogenesis and modeling the capacity of TSEs to cross the human species barrier.
To assess the zoonotic potential of prions circulating in farmed ruminants, we study their transmission ability in transgenic mice expressing human PrPC (HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC (129Met or 129Val) are used to determine the role of the Met129Val dimorphism in susceptibility/resistance to the different agents.
These transmission experiments confirm the ability of BSE prions to propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be susceptible to BSE in sheep or goat to a greater degree than the BSE agent in cattle and that these agents can convey molecular properties and neuropathological indistinguishable from vCJD. However homozygous 129V mice are resistant to all tested BSE derived prions independently of the originating species suggesting a higher transmission barrier for 129V-PrP variant.
Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
***> why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man.
***> I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough.
***> Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
snip...
R. BRADLEY
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***> Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility. <***
Transmission of scrapie prions to primate after an extended silent incubation period
Emmanuel E. Comoy, Jacqueline Mikol, Sophie Luccantoni-Freire, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Valérie Durand, Capucine Dehen, Olivier Andreoletti, Cristina Casalone, Juergen A. Richt, Justin J. Greenlee, Thierry Baron, Sylvie L. Benestad, Paul Brown & Jean-Philippe Deslys Scientific Reports volume 5, Article number: 11573 (2015) | Download Citation
Abstract
Classical bovine spongiform encephalopathy (c-BSE) is the only animal prion disease reputed to be zoonotic, causing variant Creutzfeldt-Jakob disease (vCJD) in humans and having guided protective measures for animal and human health against animal prion diseases. Recently, partial transmissions to humanized mice showed that the zoonotic potential of scrapie might be similar to c-BSE. We here report the direct transmission of a natural classical scrapie isolate to cynomolgus macaque, a highly relevant model for human prion diseases, after a 10-year silent incubation period, with features similar to those reported for human cases of sporadic CJD. Scrapie is thus actually transmissible to primates with incubation periods compatible with their life expectancy, although fourfold longer than BSE. Long-term experimental transmission studies are necessary to better assess the zoonotic potential of other prion diseases with high prevalence, notably Chronic Wasting Disease of deer and elk and atypical/Nor98 scrapie.
SNIP...
Discussion We describe the transmission of spongiform encephalopathy in a non-human primate inoculated 10 years earlier with a strain of sheep c-scrapie. Because of this extended incubation period in a facility in which other prion diseases are under study, we are obliged to consider two alternative possibilities that might explain its occurrence. We first considered the possibility of a sporadic origin (like CJD in humans). Such an event is extremely improbable because the inoculated animal was 14 years old when the clinical signs appeared, i.e. about 40% through the expected natural lifetime of this species, compared to a peak age incidence of 60–65 years in human sporadic CJD, or about 80% through their expected lifetimes. Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.
The second possibility is a laboratory cross-contamination. Three facts make this possibility equally unlikely. First, handling of specimens in our laboratory is performed with fastidious attention to the avoidance of any such cross-contamination. Second, no laboratory cross-contamination has ever been documented in other primate laboratories, including the NIH, even between infected and uninfected animals housed in the same or adjacent cages with daily intimate contact (P. Brown, personal communication). Third, the cerebral lesion profile is different from all the other prion diseases we have studied in this model19, with a correlation between cerebellar lesions (massive spongiform change of Purkinje cells, intense PrPres staining and reactive gliosis26) and ataxia. The iron deposits present in the globus pallidus are a non specific finding that have been reported previously in neurodegenerative diseases and aging27. Conversely, the thalamic lesion was reminiscent of a metabolic disease due to thiamine deficiency28 but blood thiamine levels were within normal limits (data not shown). The preferential distribution of spongiform change in cortex associated with a limited distribution in the brainstem is reminiscent of the lesion profile in MM2c and VV1 sCJD patients29, but interspecies comparison of lesion profiles should be interpreted with caution. It is of note that the same classical scrapie isolate induced TSE in C57Bl/6 mice with similar incubation periods and lesional profiles as a sample derived from a MM1 sCJD patient30.
We are therefore confident that the illness in this cynomolgus macaque represents a true transmission of a sheep c-scrapie isolate directly to an old-world monkey, which taxonomically resides in the primate subdivision (parvorder of catarrhini) that includes humans. With an homology of its PrP protein with humans of 96.4%31, cynomolgus macaque constitutes a highly relevant model for assessing zoonotic risk of prion diseases. Since our initial aim was to show the absence of transmission of scrapie to macaques in the worst-case scenario, we obtained materials from a flock of naturally-infected sheep, affecting animals with different genotypes32. This c-scrapie isolate exhibited complete transmission in ARQ/ARQ sheep (332 ± 56 days) and Tg338 transgenic mice expressing ovine VRQ/VRQ prion protein (220 ± 5 days) (O. Andreoletti, personal communication). From the standpoint of zoonotic risk, it is important to note that sheep with c-scrapie (including the isolate used in our study) have demonstrable infectivity throughout their lymphoreticular system early in the incubation period of the disease (3 months-old for all the lymphoid organs, and as early as 2 months-old in gut-associated lymph nodes)33. In addition, scrapie infectivity has been identified in blood34, milk35 and skeletal muscle36 from asymptomatic but scrapie infected small ruminants which implies a potential dietary exposure for consumers.
Two earlier studies have reported the occurrence of clinical TSE in cynomolgus macaques after exposures to scrapie isolates. In the first study, the “Compton” scrapie isolate (derived from an English sheep) and serially propagated for 9 passages in goats did not transmit TSE in cynomolgus macaque, rhesus macaque or chimpanzee within 7 years following intracerebral challenge1; conversely, after 8 supplementary passages in conventional mice, this “Compton” isolate induced TSE in a cynomolgus macaque 5 years after intracerebral challenge, but rhesus macaques and chimpanzee remained asymptomatic 8.5 years post-exposure8. However, multiple successive passages that are classically used to select laboratory-adapted prion strains can significantly modify the initial properties of a scrapie isolate, thus questioning the relevance of zoonotic potential for the initial sheep-derived isolate. The same isolate had also induced disease into squirrel monkeys (new-world monkey)9. A second historical observation reported that a cynomolgus macaque developed TSE 6 years post-inoculation with brain homogenate from a scrapie-infected Suffolk ewe (derived from USA), whereas a rhesus macaque and a chimpanzee exposed to the same inoculum remained healthy 9 years post-exposure1. This inoculum also induced TSE in squirrel monkeys after 4 passages in mice. Other scrapie transmission attempts in macaque failed but had more shorter periods of observation in comparison to the current study. Further, it is possible that there are differences in the zoonotic potential of different scrapie strains.
The most striking observation in our study is the extended incubation period of scrapie in the macaque model, which has several implications. Firstly, our observations constitute experimental evidence in favor of the zoonotic potential of c-scrapie, at least for this isolate that has been extensively studied32,33,34,35,36. The cross-species zoonotic ability of this isolate should be confirmed by performing duplicate intracerebral exposures and assessing the transmissibility by the oral route (a successful transmission of prion strains through the intracerebral route may not necessarily indicate the potential for oral transmission37). However, such confirmatory experiments may require more than one decade, which is hardly compatible with current general management and support of scientific projects; thus this study should be rather considered as a case report.
Secondly, transmission of c-BSE to primates occurred within 8 years post exposure for the lowest doses able to transmit the disease (the survival period after inoculation is inversely proportional to the initial amount of infectious inoculum). The occurrence of scrapie 10 years after exposure to a high dose (25 mg) of scrapie-infected sheep brain suggests that the macaque has a higher species barrier for sheep c-scrapie than c-BSE, although it is notable that previous studies based on in vitro conversion of PrP suggested that BSE and scrapie prions would have a similar conversion potential for human PrP38.
Thirdly, prion diseases typically have longer incubation periods after oral exposure than after intracerebral inoculations: since humans can develop Kuru 47 years after oral exposure39, an incubation time of several decades after oral exposure to scrapie would therefore be expected, leading the disease to occur in older adults, i.e. the peak age for cases considered to be sporadic disease, and making a distinction between scrapie-associated and truly sporadic disease extremely difficult to appreciate.
Fourthly, epidemiologic evidence is necessary to confirm the zoonotic potential of an animal disease suggested by experimental studies. A relatively short incubation period and a peculiar epidemiological situation (e.g., all the first vCJD cases occurring in the country with the most important ongoing c-BSE epizootic) led to a high degree of suspicion that c-BSE was the cause of vCJD. Sporadic CJD are considered spontaneous diseases with an almost stable and constant worldwide prevalence (0.5–2 cases per million inhabitants per year), and previous epidemiological studies were unable to draw a link between sCJD and classical scrapie6,7,40,41, even though external causes were hypothesized to explain the occurrence of some sCJD clusters42,43,44. However, extended incubation periods exceeding several decades would impair the predictive values of epidemiological surveillance for prion diseases, already weakened by a limited prevalence of prion diseases and the multiplicity of isolates gathered under the phenotypes of “scrapie” and “sporadic CJD”.
Fifthly, considering this 10 year-long incubation period, together with both laboratory and epidemiological evidence of decade or longer intervals between infection and clinical onset of disease, no premature conclusions should be drawn from negative transmission studies in cynomolgus macaques with less than a decade of observation, as in the aforementioned historical transmission studies of scrapie to primates1,8,9. Our observations and those of others45,46 to date are unable to provide definitive evidence regarding the zoonotic potential of CWD, atypical/Nor98 scrapie or H-type BSE. The extended incubation period of the scrapie-affected macaque in the current study also underscores the limitations of rodent models expressing human PrP for assessing the zoonotic potential of some prion diseases since their lifespan remains limited to approximately two years21,47,48. This point is illustrated by the fact that the recently reported transmission of scrapie to humanized mice was not associated with clinical signs for up to 750 days and occurred in an extreme minority of mice with only a marginal increase in attack rate upon second passage13. The low attack rate in these studies is certainly linked to the limited lifespan of mice compared to the very long periods of observation necessary to demonstrate the development of scrapie. Alternatively, one could estimate that a successful second passage is the result of strain adaptation to the species barrier, thus poorly relevant of the real zoonotic potential of the original scrapie isolate of sheep origin49. The development of scrapie in this primate after an incubation period compatible with its lifespan complements the study conducted in transgenic (humanized) mice; taken together these studies suggest that some isolates of sheep scrapie can promote misfolding of the human prion protein and that scrapie can develop within the lifespan of some primate species.
In addition to previous studies on scrapie transmission to primate1,8,9 and the recently published study on transgenic humanized mice13, our results constitute new evidence for recommending that the potential risk of scrapie for human health should not be dismissed. Indeed, human PrP transgenic mice and primates are the most relevant models for investigating the human transmission barrier. To what extent such models are informative for measuring the zoonotic potential of an animal TSE under field exposure conditions is unknown. During the past decades, many protective measures have been successfully implemented to protect cattle from the spread of c-BSE, and some of these measures have been extended to sheep and goats to protect from scrapie according to the principle of precaution. Since cases of c-BSE have greatly reduced in number, those protective measures are currently being challenged and relaxed in the absence of other known zoonotic animal prion disease. We recommend that risk managers should be aware of the long term potential risk to human health of at least certain scrapie isolates, notably for lymphotropic strains like the classical scrapie strain used in the current study. Relatively high amounts of infectivity in peripheral lymphoid organs in animals infected with these strains could lead to contamination of food products produced for human consumption. Efforts should also be maintained to further assess the zoonotic potential of other animal prion strains in long-term studies, notably lymphotropic strains with high prevalence like CWD, which is spreading across North America, and atypical/Nor98 scrapie (Nor98)50 that was first detected in the past two decades and now represents approximately half of all reported cases of prion diseases in small ruminants worldwide, including territories previously considered as scrapie free... Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
FRIDAY, APRIL 22, 2016
Texas Scrapie Confirmed in a Hartley County Sheep where CWD was detected in a Mule Deer April 22, 2016
Scrapie Field Trial Experiments Mission, Texas
A Scrapie Field Trial was developed at Mission, Texas, to provide additional information for the eradication program on the epidemiology of natural scrapie. The Mission Field Trial Station is located on 450 acres of pastureland, part of the former Moore Air Force Base, near Mission, Texas. It was designed to bring previously exposed, and later also unexposed, sheep or goats to the Station and maintain and breed them under close observation for extended periods to determine which animals would develop scrapie and define more closely the natural spread and other epidemiological aspects of the disease.
The 547 previously exposed sheep brought to the Mission Station beginning in 1964 were of the Cheviot, Hampshire, Montadale, or Suffolk breeds. They were purchased as field outbreaks occurred, and represented 21 bloodlines in which scrapie had been diagnosed. Upon arrival at the Station, the sheep were maintained on pasture, with supplemental feeding as necessary. The station was divided into 2 areas: (1) a series of pastures and-pens occupied by male animals only, and (2) a series of pastures and pens occupied by females and young progeny of both sexes. ...
snip...see full text ;
Mission, Texas Scrapie transmission to cattle study
Wilbur Clarke (reference the Mission, Texas scrapie transmission transmission to cattle study) is now the State Veterinarian for Montana based at Helena.
I was given confidential access to sections from the Clarke scrapie-cattle transmission experiment. Details of the experimental design were as supplied previously by Dr. Wrathall (copy of relevant information appended). Only 3 animals (2 inoculated with 2nd pass Suffolk scrapie and 1 inoculated with Angora goat passaged scrapie) showed clinical signs. Clinical signs were characterised by weakness, ''a stilted hindlimb gait'', disorientation, ataxia and, terminally, lateral recumbency. The two cattle from which I examined material were inocluated at 8 months of age and developed signs 36 months pi (goat scrapie inoculum) and 49 months pi (one of the Suffolk scrapie inoculated) respectively. This latter animal was killed at 58 months of age and so the clinical duration was only 1 month. The neuropathology was somewhat different from BSE or the Stetsonville TME in cattle. Vacuolar changes were minimal, to the extent that detection REQUIRED CAREFUL SEARCHING. Conversely astrocyte hypertrophy was a widespread and prominent feature. The material requires DETAILED NEUROPATHOLOGICAL ASSESSMENT BUT WHETHER OR NOT THIS WILL BE DONE REMAINS A QUESTION.
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases {the following was written but with a single line marked through it ''first passage (by this route)}...TSS
resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. One control animal became affected, it is believed through contamination of inoculum (?saline). Further CWD transmissions were carried out by Dick Marsh into ferret, mink and squirrel monkey. Transmission occurred in ALL of these species with the shortest incubation period in the ferret.
snip...
Appendix 3
VISIT TO USA - DR A E WRATHALL - INFO OH BSE AND SCRAPIE
1. Dr Clark lately of the Scrapie Research Unit, Mission Texas has successfully transmitted ovine and caprine scrapie to cattle. The experimental results have not been published but there are plans to do this. This work was initiated in 1978.
A summary of it is:-
Expt A
6 Her x Jer calves born in 1978 were inoculated as follows with
a 2nd Suffolk scrapie passage:-
i/c 1ml; i/m, 5ml; s/c 5ml; oral 30ml.
1/6 went down after 48 months with a scrapie/BSE-like disease.
Expt B
6 Her or Jer or HxJ calves were inoculated with angora Goat
virus 2/6 went down similarly after 36 months.
Expt C
Mice inoculated from brains of calves/cattle in expts A • B were resistant, only 1/20 going down with scrapie and this was the reason given for not publishing.
Diagnosis in A, B, C was by histopath. No reports on SAT were given.
2. Dr Warren Foote indicated success so far in eliminating scrapie in offspring from experimentally- (and naturally) infected sheep by ET. He had found difficulty in obtaining embryos from naturally infected sheep (cf SPA).
3. Prof. A Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr A Thiermann showed the picture in the "Independent" with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs. BSE was not reported in USA.
4. Scrapie incidents (ie affected flocks) have shown a dramatic increase since 1978. In 1953 when the National Control Scheme was started there were 10-14 incidents, in 1978 - 1 and in 1988 so far 60.
5. Scrapie agent was reported to have been isolated from a solitary fetus.
6. A western blotting diagnostic technique (? on PrP) shows some promise.
7. Results of a questionnaire sent to 33 states on the subject of the national sheep scrapie programme survey indicated
17/33 wished to drop it
6/33 wished to develop it
9/13/2005
33
Page 15 of 17
8/33 had few sheep and were neutral
Information obtained from Dr Wrathall's notes of a meeting of the U.S. Animal Health Association at Little Rock, Arkansas Nov. 1988.
end...TSS
Thursday, June 09, 2016
Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force Base Scrapie TSE Prion Experiment 1964 How Did CWD Get Way Down In Medina County, Texas?
DISCUSSION
Observations of natural outbreaks of scrapie indicated that the disease spread from flock to flock by the movement of infected, but apparently normal, sheep which were incubating the disease.
There was no evidence that the disease spread to adjacent flocks in the absent of such movements or that vectors or other host species were involved in the spread of scrapie to sheep or goats; however, these possibilities should be kept open...
IN CONFIDENCE
MEETING ON THE FEASIBILITY OF CARRYING OUT EPIDEMIOLOGICAL STUDIES ON CREUTZFELDT JAKOB DISEASE 1978
THE SCRAPIE FILES IN CONFIDENCE CONFIDENTIAL SCJD
MEETING ON THE FEASIBILITY OF CARRYING OUT EPIDEMIOLOGICAL STUDIES ON CREUTZFELDT JAKOB DISEASE 1978
THE SCRAPIE FILES
CONFIDENTIAL
IN CONFIDENCE SCJD
Subject: 1978 SCRAPIE IN CONFIDENCE SCJD
1978 SCRAPIE IN CONFIDENCE SCJD
Annex:
MEDICAL RESEARCH COUNCIL
IN CONFIDENCE
Circulation Participants
MEETING ON THE FEASIBILITY OF CARRYING OUT EPIDEMIOLOGICAL STUDIES ON CREUTZFELDT-JAKOB DISEASE
Minutes of meeting held on Thursday 9 March 1978 at 20 Park Crescent London WIN 4AL
Present: Professor J N Walton (Chairman), Dr A M Adelstein, Professor J R Batchelor, Mr K N Burns (ARC), Professor J A N Corsellis, Dr T J Crow, Dr R Levy, Professor W B Matthews, Dr J T Stamp, Professor B E Tomlinson, Professor M P Vessey, Professor P Wildy, Dr A Smithies (Health Department Observer).
Headquarters staff: Dr Katherine levy, Dr Victoria Harrison, Miss Roberta Withnall.
Amlogies for absence: Professor A N Davison, Dr R H Kimberlin, Dr W A Lishman, Professor C A Mims-
1. Introduction and background
The Chairman opened the meeting by explaining that its purpose was to advise the Neurosciences Board on the value and feasibility of carrying out epidemiological studies on Creutzfeldt—Jakob (C—J) disease; suggestions for work on other aspects of the disease were not, however, precluded.
***The meeting had been called following the Agricultural Research Council's (ARC) report of their Advisory Committee on Scrapie, a document which should be regarded as confidential.
One of the main issues which merited discussion was whether those whose occupation suggested they might be in contact with scrapie had a higher risk of developing C—J disease. While fully appreciating that the problem of infectivity was one of great concern the present meeting was not constituted to discuss this problem per se. The recently set up ARC Advisory Group on Scrapie would be taking up this question; it was also of concern to the Health Departments who wished to be kept informed of developments. Mr Burns reported that the ARC had already had preliminary discussions on the safety aspects which would be necessary in the event of C—J work being carried out in their Institute at Compton. Dr Levy agreed to act as liaison officer between the two Councils and the Health Departments.
The meeting considered the mortality data provided by OPCS (CJD 78/2) and that provided by Professor Matthews (paper tabled). The interpretation of these data was complicated by possibilities of both under and over reporting. Under-reporting was likely in that G—J disease might:
(a) be undiagnosed, particularly in large mental hospitals; and
(b) not appear on death certificates either because the actual cause of death was eg. bronchial pneumonia, or because reference to dementia (in any form) was excluded to spare the feelings of the family. Over-reporting might occur because, although the rapidly progressive form of the disease was readily diagnosed in life, the less dramatic forms were more difficult. to recognise clinically and could be diagnosed in error (see below). It was notes: that the OPCS data showed an apparently higher incidence of the disease in social class I: a possible explanation was that this group was investigated more carefully. An added difficulty, common to all occupational data obtained from death certificates alone, was that it was based solely on information provided by the person registering the death. Professor Vessey drew attention to the temporal differences between the OPCS data and those provided by Professor Matthews.
S 803/10 78/3.9/1.1
The meeting then considered the implication of:
a) incompleteness; and
b) inaccuracy of the data. Incompleteness would matter if it was associated with the factor under study, eg. if only those cases occurring in certain occupational groups were missing: if accurate incidence, prevalence or mortality rates were required; and in examining space/time clustering (see below). Inaccuracy would matter less since the dilution of the mortality data with diseases other than C—J would merely tend to weaken any association present.
3. Accuracy of clinical diagnosis: neuropathology
The neuropathologists present explained that it was now generally considered that there were 3 categories of the disease:
(i) a rapidly progressive form of subacute spongiform encephalopathy (the Nevin—Jones Syndrome) usually leading to death within 6—9 months; this is the only form which has been transmitted to animals;
(ii) a variant in which the cerebellum appears to bear the brunt of the pathology and
(iii) "classical" C—J disease which follows a more protracted course. Diagnosis is based on the typical EEG picture - which in the slower forms of the disease may not arise until late in the course of the illness — and on the characteristic spongiform features seen on neuropathological examination. The less rapidly progressive forms could be confused with other forms of dementia or arteriosclerotic disease, Alzheimer's disease with myoclonus, myoclonic epilepsy, corticostrionigral degeneration, Pick's disease or motor neurone disease.
While there could be doubt about a diagnosis made on a biopsy specimen it would be very rare for a neuropathologist to make a mistake at autopsy. However, in less specialised hands there was a very significant chance that cases could be missed.
Dr Stamp pointed out that in scrapie no spongiform encephalopathy was detected and that in many cases confirmed by transmission experiments no neuropathological abnormality could be found.
4. Specialist care of C—J patients
The question of whether C—J patients Were in the main looked after by neurologists or by psychiatrists was discussed. The View of the meeting was that most patients were seen by neurologists, but that there might be an unknown, even considerable number of cases (presumably of the more chronic form) in major mental hospitals.
5. Frequency of biopsies and post mortems
Until a few years ago a biopsy was carried out in the majority of suspected case. referred to major centres: the situation had now changed and biopsies were performed less often, partly because diagnosis could be based on the clinical and EEG
picture .
Dr Adelstein pointed out that 50% of C-J deaths recorded in the OPCS figures had come to post mortem, during the six year period up to 1976. The figures may be dropping for both biopsies and post mortems not only because they are thought unnecessary in view of the improvement in other methods of diagnosis but also because of both the shortage of neuropathologists and their awareness of the possible infectivity of the agent.*
*‘There is no evidence to suggest that there is only one agent; there may well be several. But for the purposes of this record the term 'agent‘ is used throughout
-2-
78/3.9/1.2
6. Gajdusek's evidence
The Chairman invited Professor Wildy to speak to his paper (CJD 78/3) on the hazards of the C—J agent and other possible agents to hospital staff and pathologists. Professor Wildy emphasised that in general Gajdusek's evidence should be treated with great caution since his hypothesis was based on the presumed analogy with the scrapie agent (or agents). Hard data were not available about the C—J agent itself. It was resistant to many physical and chemical treatments: there was a need to establish a reliable means of sterilisation, as Gajdusek's published data on autoclaving was open to criticism. It is likely that, as with scrapie, some C—J strains would prove to be much more resistant than others.
7. Risk of infection
The two reports of iatrogenic man—to—man transmission of C—J disease have involved corneal grafting and neurosurgery respectively. While the implications for sterilisation of instruments etc. had been widely discussed in the literature the additional point was made that corneae for grafts were often obtained from old peoples' homes: caution should therefore be exercised in using tissue from this source.
Overall there was no indication either from OPCS data or from anecdotal evidence that pathologists, mortuary attendants or research workers had ever developed C—J disease. On available evidence it was, however, clear that contact between C—J infected material and lacerated skin must be avoided. Nor was there evidence that anyone working with scrapie diseased animals (veterinary surgeons, slaughter house workers, butchers, shepherds and shepherdesses or research workers) have developed the disease. It was nonetheless worth undertaking retrospective epidemiological studies if only to provide reassurance that there was no excess mortality from C—J disease in these and other professional groups — including neurosurgeons, neurologists, undertakers and embalmers. It should however be borne in mind that some of the latter categories may be under—represented, occupation euphemisms having been used on the death certificates.
8. Prevalence and mode of infectivity of C—J agent
While the prevalence and mode of infectivity of the C—J agent are unknown it would be difficult to account for the world wide distribution of the disease unless the agent were common. If prevalence were low it would be difficult to postulate how the agent would replicate. This suggested that one might be dealing with a transferred ubiquitous and relatively banal agent — the analogy being measles and SSPE. It was agreed that while this was pure speculation, the possibility could not be ruled out. Dr Crow pointed out that the age incidence of C—J disease would not suggest that it was due to an infective agent. In this connection Dr Stamp reported that both lateral and vertical transmission occur in scrapie: genetic factors determine the incubation period and so—called "resistant" sheep may die before there was time for them to show clinical signs of the disease. It was not known how scrapie was transmitted, though it can exist outside its host for an indefinite period. However the usefulness of the scrapie analogy is uncertain. Dr Stamp emphasised that in scrapie the innoculated and natural disease are two very different conditions.
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78/3.9/1.3
9. Clusters, familial incidence and conjugal C—J disease
Geographical and temporal clustering have been reported; these however had been small and difficult to evaluate statistically. In Professor Tomlinson's experience all cases of C—J were referrals from the better known neurological or psychiatric centres, implying that clustering could be an artefact. Professor Vessey offered with colleagues to examine the data provided by OPCS and Professor Matthews to see if these revealed any evidence of clustering. Different incubation periods could be built in and contact between cases could be looked for - the complex statistics had been worked out for Hodgkin's disease. The technique involved was nevertheless a crude one. Familial cases had been reported but the numbers involved were too low to be significant. Occurrence of the disease in cousins (2 in the UK, and 2 in the USA) and two cases of conjugal C—J disease were briefly mentioned.
10. Genetic screening, including HLA status
Professor Batchelor confirmed that the HLA status of C—J patients had not been investigated. Dr Stamp reported that there was no association with mouse histocompatibility antigens in scrapie; this had not been investigated in sheep. Professor Batchelor said that typing would not be difficult: 30—60 patients would be required depending on the rarity of the antigen. General genetic screening might also be worthwhile; he suggested that the Galton laboratories might be approached with a view to studying various isoenzymes in such cases. Samples of serum should be stored for future study of antibody profiles.
11 . General conclusions
(i) The meeting could only confirm that the epidemiology of C—J disease is poorly understood.
(ii) The existing mortality data were likely to be inaccurate; so far as they went no occupational association with the disease could be demonstrated. The prevalence and mode of infectivity of the agent were unknown and clusters reported had been small and difficult to evaluate statistically.
(iii) Gajdusek‘s evidence was open to criticism: however, while his assertions are unsupported by hard data, his claims might nonetheless have substance.
(iv) While the-analogy with scrapie was interesting and the scrapie and C—J agents displayed similarities in behaviour and character, there was no proof that the scrapie agent was in any way associated with C-J disease.
12. Possible action
The following suggestions were made about action which might be taken:
(1) OPCS might be asked to provide data on the occupations listed for all deaths due to dementia and the other diseases with which C—J might be confused recorded within, say, the last 3 years.
(ii) OPCS might be asked to collect prospectively notifications of all deaths from C—J disease, the dementias and other diseases with which it might be confused.
(iii) The data provided by OPCS might be correlated with that obtained by Professor Matthews (confirming diagnoses from case notes etc. in at least a sample of these cases) to see how many of the same C—J patients were involved. These data should be analysed for evidence of clustering.
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(iv) Data provided by the Doll/Hill study of 34,000 doctors on the medical register in 1953 might (with the authors' agreement) be utilised to see if any excess death rates from C—J-disease, the dementias or other diseases with which it may be confused, could be identified among certain specialist groups.
(v) HLA status of C—J patients should be determined.
(vi) General genetic screening might be undertaken of patients with C—J disease.
(vii) Samples of serum from C—J patients should be stored for future study of antibody profiles.
(viii) Although technically outside their remit the meeting recommended that good work should be encouraged on the isolation, characterisation, distribution in the body, routes of infection and methods of destruction of the C—J agent.
The Chairman closed the meeting by thanking the participants for attending and for their help in reaching these conclusions.
78/3.9/1.5
IN CONFIDENCE
BE SURE TO SEE THIS NEXT ONE WITH FIGURES...TSS
STUDIES ON CREUTZFELDT-JAKOB DISEASE
i enclose a list of ICD categories showing the numbers of deaths attributed to each (as underlying cause) in England and Hales in 1975.
ICD NO...Number of Certificates examined
xxxxx...18...15 mentioned C-J
xxxxx...122...1 mentioned C-J with dimentia, 24 mentioned Alzheimer’s disease, 1 mentioned Pick’s disease.
xxxxx...22...4 mentioned Myoclonic epilepsy
xxxxx...384...none mentioned Corticostrionigral degeneration
xxxxx...2...none mentioned Corticostrionigral degeneration
snip...
see board meeting on questions raised on whether risk factors, occupation, for those that worked with scrapie, had a higher risk of developing creutzfeldt jakob disease...see;
IN CONFIDENCE
1979
SILENCE ON CJD AND SCRAPIE
1980
SILENCE ON CJD AND SCRAPIE
*** 1981 NOVEMBER
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
12/10/76
AGRICULTURAL RESEARCH COUNCIL REPORT OF THE ADVISORY COMMITTE ON SCRAPIE
Office Note CHAIRMAN: PROFESSOR PETER WILDY
snip...
A The Present Position with respect to Scrapie A] The Problem Scrapie is a natural disease of sheep and goats. It is a slow and inexorably progressive degenerative disorder of the nervous system and it ia fatal. It is enzootic in the United Kingdom but not in all countries. The field problem has been reviewed by a MAFF working group (ARC 35/77). It is difficult to assess the incidence in Britain for a variety of reasons but the disease causes serious financial loss; it is estimated that it cost Swaledale breeders alone $l.7 M during the five years 1971-1975. A further inestimable loss arises from the closure of certain export markets, in particular those of the United States, to British sheep. It is clear that scrapie in sheep is important commercially and for that reason alone effective measures to control it should be devised as quickly as possible. Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates.
One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias" Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
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76/10.12/4.6
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
why do we not want to do TSE transmission studies on chimpanzees $
full text ;
RB3.20
IN CONFIDENCE
TRANSMISSION TO CHIMPANZEE
1. Kuru and CJD have been successfully transmitted to chimpanzees but scrapie and TME have not.
2. We cannot say that scrapie will not transmit to chimpanzees. There are several scrapie strains and I am not aware that all have been tried (that would have to be from mouse passaged material). Nor has a wide enough range of field isolates subsequently strain typed in mice been inoculated by the appropriate routes (i/c, i/p and i v);
3. I believe the proposed experiment to determine transmissibility, if conducted, would only show the susceptibility or resistance of the chimpanzee to infection/disease by the routes used and the result could not be interpreted for the predictability of the susceptibility for man. Proposals for prolonged oral exposure of chimpanzees to milk from cattle were suggested a long while ago and rejected.
4. In view of Dr Gibbs‘ probable use of Chimpazees Mr Wells‘ comments (enclosed) are pertinent. I have yet to receive a direct communication from Dr Schellekers but before any collaboration or provision of material we should identify the Gibbs' proposals and objectives.
5. A positive result from a chimpanzee challenged severely would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
A negative result would take a lifetime to determine but that would be a shorter period than might be available for human exposure and it would still not answer the question regarding mans' susceptibility. In the meantime no doubt the negativity would be used defensively. It would however be counterproductive if the experiment finally became positive- We may learn more about public reactions following next Monday‘s meeting. CVO (+ Mr. Wells’ comments)
Dr. T W A Little
Dr. B J Shreeve
R Bradley September 1990
90/9.23/1/1
Wednesday, February 16, 2011
IN CONFIDENCE
SCRAPIE TRANSMISSION TO CHIMPANZEES
IN CONFIDENCE
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Transmission of scrapie prions to primate after an extended silent incubation period
Authors
item Comoy, Emmanuel - item Mikol, Jacqueline - item Luccantoni-Freire, Sophie - item Correia, Evelyne - item Lescoutra-Etchegaray, Nathalie - item Durand, Valérie - item Dehen, Capucine - item Andreoletti, Olivier - item Casalone, Cristina - item Richt, Juergen item Greenlee, Justin item Baron, Thierry - item Benestad, Sylvie - item Hills, Bob - item Brown, Paul - item Deslys, Jean-Philippe -
Submitted to: Scientific Reports Publication Type: Peer Reviewed Journal Publication Acceptance Date: May 28, 2015 Publication Date: June 30, 2015 Citation: Comoy, E.E., Mikol, J., Luccantoni-Freire, S., Correia, E., Lescoutra-Etchegaray, N., Durand, V., Dehen, C., Andreoletti, O., Casalone, C., Richt, J.A., Greenlee, J.J., Baron, T., Benestad, S., Brown, P., Deslys, J. 2015. Transmission of scrapie prions to primate after an extended silent incubation period. Scientific Reports. 5:11573.
Interpretive Summary: The transmissible spongiform encephalopathies (also called prion diseases) are fatal neurodegenerative diseases that affect animals and humans. The agent of prion diseases is a misfolded form of the prion protein that is resistant to breakdown by the host cells. Since all mammals express prion protein on the surface of various cells such as neurons, all mammals are, in theory, capable of replicating prion diseases. One example of a prion disease, bovine spongiform encephalopathy (BSE; also called mad cow disease), has been shown to infect cattle, sheep, exotic undulates, cats, non-human primates, and humans when the new host is exposed to feeds or foods contaminated with the disease agent. The purpose of this study was to test whether non-human primates (cynomologous macaque) are susceptible to the agent of sheep scrapie. After an incubation period of approximately 10 years a macaque developed progressive clinical signs suggestive of neurologic disease. Upon postmortem examination and microscopic examination of tissues, there was a widespread distribution of lesions consistent with a transmissible spongiform encephalopathy. This information will have a scientific impact since it is the first study that demonstrates the transmission of scrapie to a non-human primate with a close genetic relationship to humans. This information is especially useful to regulatory officials and those involved with risk assessment of the potential transmission of animal prion diseases to humans. Technical Abstract: Classical bovine spongiform encephalopathy (c-BSE) is an animal prion disease that also causes variant Creutzfeldt-Jakob disease in humans. Over the past decades, c-BSE's zoonotic potential has been the driving force in establishing extensive protective measures for animal and human health.
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***> Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
Atypical NOR98 Scrapie to humans as sporadic CJD
Sporadic CJD type 1 and atypical/ Nor98 scrapie are characterized by fine (reticular) deposits, see also ; All of the Heidenhain variants were of the methionine/ methionine type 1 molecular subtype.
AND WHAT HAVE THE PRION GODS SAID OF THE ATYPICAL NOR-98, AND IT'S POTENTIAL FOR TRANSMISSION TO HUMANS ;
A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes
Annick Le Dur*,?, Vincent Béringue*,?, Olivier Andréoletti?, Fabienne Reine*, Thanh Lan Laï*, Thierry Baron§, Bjørn Bratberg¶, Jean-Luc Vilotte?, Pierre Sarradin**, Sylvie L. Benestad¶, and Hubert Laude*,?? +Author Affiliations
*Virologie Immunologie Moléculaires and ?Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; ?Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; §Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway
***Edited by Stanley B. Prusiner, University of California, San Francisco, CA (received for review March 21, 2005)
Abstract Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice.
*** These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
OR
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
OR
*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.
*** The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.
VARIABLY PROTEASE-SENSITVE PRIONOPATHY IS TRANSMISSIBLE ...price of prion poker goes up again $
OR-10: Variably protease-sensitive prionopathy is transmissible in bank voles
Romolo Nonno,1 Michele Di Bari,1 Laura Pirisinu,1 Claudia D’Agostino,1 Stefano Marcon,1 Geraldina Riccardi,1 Gabriele Vaccari,1 Piero Parchi,2 Wenquan Zou,3 Pierluigi Gambetti,3 Umberto Agrimi1 1Istituto Superiore di Sanità; Rome, Italy; 2Dipartimento di Scienze Neurologiche, Università di Bologna; Bologna, Italy; 3Case Western Reserve University; Cleveland, OH USA
Background. Variably protease-sensitive prionopathy (VPSPr) is a recently described “sporadic”neurodegenerative disease involving prion protein aggregation, which has clinical similarities with non-Alzheimer dementias, such as fronto-temporal dementia. Currently, 30 cases of VPSPr have been reported in Europe and USA, of which 19 cases were homozygous for valine at codon 129 of the prion protein (VV), 8 were MV and 3 were MM. A distinctive feature of VPSPr is the electrophoretic pattern of PrPSc after digestion with proteinase K (PK). After PK-treatment, PrP from VPSPr forms a ladder-like electrophoretic pattern similar to that described in GSS cases. The clinical and pathological features of VPSPr raised the question of the correct classification of VPSPr among prion diseases or other forms of neurodegenerative disorders. Here we report preliminary data on the transmissibility and pathological features of VPSPr cases in bank voles.
Materials and Methods. Seven VPSPr cases were inoculated in two genetic lines of bank voles, carrying either methionine or isoleucine at codon 109 of the prion protein (named BvM109 and BvI109, respectively). Among the VPSPr cases selected, 2 were VV at PrP codon 129, 3 were MV and 2 were MM. Clinical diagnosis in voles was confirmed by brain pathological assessment and western blot for PK-resistant PrPSc (PrPres) with mAbs SAF32, SAF84, 12B2 and 9A2.
Results. To date, 2 VPSPr cases (1 MV and 1 MM) gave positive transmission in BvM109. Overall, 3 voles were positive with survival time between 290 and 588 d post inoculation (d.p.i.). All positive voles accumulated PrPres in the form of the typical PrP27–30, which was indistinguishable to that previously observed in BvM109 inoculated with sCJDMM1 cases.
In BvI109, 3 VPSPr cases (2 VV and 1 MM) showed positive transmission until now. Overall, 5 voles were positive with survival time between 281 and 596 d.p.i.. In contrast to what observed in BvM109, all BvI109 showed a GSS-like PrPSc electrophoretic pattern, characterized by low molecular weight PrPres. These PrPres fragments were positive with mAb 9A2 and 12B2, while being negative with SAF32 and SAF84, suggesting that they are cleaved at both the C-terminus and the N-terminus. Second passages are in progress from these first successful transmissions.
Conclusions. Preliminary results from transmission studies in bank voles strongly support the notion that VPSPr is a transmissible prion disease. Interestingly, VPSPr undergoes divergent evolution in the two genetic lines of voles, with sCJD-like features in BvM109 and GSS-like properties in BvI109.
The discovery of previously unrecognized prion diseases in both humans and animals (i.e., Nor98 in small ruminants) demonstrates that the range of prion diseases might be wider than expected and raises crucial questions about the epidemiology and strain properties of these new forms. We are investigating this latter issue by molecular and biological comparison of VPSPr, GSS and Nor98.
Monday, June 27, 2011
Comparison of Sheep Nor98 with Human Variably Protease-Sensitive Prionopathy and Gerstmann-Sträussler-Scheinker Disease
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994
Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss) These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...
Table 9 presents the results of an analysis of these data.
There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).
Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.
There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).
The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).
The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
Thursday, October 10, 2013
CJD REPORT 1994 increased risk for consumption of veal and venison and lamb
Monday, November 30, 2009
USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE
Thursday, December 20, 2012
*** OIE GROUP RECOMMENDS THAT SCRAPE PRION DISEASE BE DELISTED, WISHES TO CONTINUE SPREADING IT AROUND THE GLOBE
P.97: Scrapie transmits to white-tailed deer by the oral route and has a molecular profile similar to chronic wasting disease and distinct from the scrapie inoculum
Justin Greenlee1, S JO Moore1, Jodi Smith1, M Heather WestGreenlee2 and Robert Kunkle1
1National Animal Disease Center; Ames, IA USA
2Iowa State University; Ames, IA USA
The purpose of this work was to determine susceptibility of white-tailed deer (WTD) to the agent of sheep scrapie and to compare the resultant PrPSc to that of the original inoculum and chronic wasting disease (CWD). We inoculated WTD by a natural route of exposure (concurrent oral and intranasal (IN); n = 5) with a US scrapie isolate. All scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues at preclinical time points, and deer necropsied after 28 months post-inoculation had clinical signs, spongiform encephalopathy, and widespread distribution of PrPSc in neural and lymphoid tissues. Western blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral cortex had a profile similar to the original scrapie inoculum, whereas WB of brainstem, cerebellum, or lymph nodes revealed PrPSc with a higher profile resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical scrapie were further passaged to mice expressing cervid prion protein and intranasally to sheep and WTD. In cervidized mice, the 2 inocula have distinct incubation times. Sheep inoculated intranasally with WTD derived scrapie developed disease, but only after inoculation with the inoculum that had a scrapie-like profile. The WTD study is ongoing, but deer in both inoculation groups are positive for PrPSc by rectal mucosal biopsy.
***In summary, this work demonstrates that WTD are susceptible to the agent of scrapie, 2 distinct molecular profiles of PrPSc are present in the tissues of affected deer, and inoculum of either profile readily passes to deer.
*** After a natural route of exposure, 100% of WTD were susceptible to scrapie.
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
White-tailed deer are susceptible to the agent of sheep scrapie by intracerebral inoculation
snip...
It is unlikely that CWD will be eradicated from free-ranging cervids, and the disease is likely to continue to spread geographically [10]. However, the potential that white-tailed deer may be susceptible to sheep scrapie by a natural route presents an additional confounding factor to halting the spread of CWD. This leads to the additional speculations that
1) infected deer could serve as a reservoir to infect sheep with scrapie offering challenges to scrapie eradication efforts and
2) CWD spread need not remain geographically confined to current endemic areas, but could occur anywhere that sheep with scrapie and susceptible cervids cohabitate.
This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by intracerebral inoculation with a high attack rate and that the disease that results has similarities to CWD. These experiments will be repeated with a more natural route of inoculation to determine the likelihood of the potential transmission of sheep scrapie to white-tailed deer. If scrapie were to occur in white-tailed deer, results of this study indicate that it would be detected as a TSE, but may be difficult to differentiate from CWD without in-depth biochemical analysis.
2012
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture; Agricultural Research Service, National Animal Disease Center; Ames, IA USA
snip...
The results of this study suggest that there are many similarities in the manifestation of CWD and scrapie in WTD after IC inoculation including early and widespread presence of PrPSc in lymphoid tissues, clinical signs of depression and weight loss progressing to wasting, and an incubation time of 21-23 months. Moreover, western blots (WB) done on brain material from the obex region have a molecular profile similar to CWD and distinct from tissues of the cerebrum or the scrapie inoculum. However, results of microscopic and IHC examination indicate that there are differences between the lesions expected in CWD and those that occur in deer with scrapie: amyloid plaques were not noted in any sections of brain examined from these deer and the pattern of immunoreactivity by IHC was diffuse rather than plaque-like.
*** After a natural route of exposure, 100% of WTD were susceptible to scrapie.
Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer exhibited two different molecular profiles: samples from obex resembled CWD whereas those from cerebrum were similar to the original scrapie inoculum. On further examination by WB using a panel of antibodies, the tissues from deer with scrapie exhibit properties differing from tissues either from sheep with scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are strongly immunoreactive when probed with mAb P4, however, samples from WTD with scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4 or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly immunoreactive and samples from WTD with scrapie are strongly positive. This work demonstrates that WTD are highly susceptible to sheep scrapie, but on first passage, scrapie in WTD is differentiable from CWD.
2011
*** After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie.
Transmissible Spongiform Encephalopathy TSE Prion End of Year Report 2020
CJD FOUNDATION VIRTUAL CONFERENCE CJD Foundation Research Grant Recipient Reports Panel 2 Nov 3, 2020
zoonotic potential of PMCA-adapted CWD PrP 96SS inoculum
4 different CWD strains, and these 4 strains have different potential to induce any folding of the human prion protein.
***> PIGS, WILD BOAR, CWD <***
***> POPULATIONS OF WILD BOARS IN THE UNITED STATES INCREASING SUPSTANTUALLY AND IN MANY AREAS WE CAN SEE A HIGH DENSITY OF WILD BOARS AND HIGH INCIDENT OF CHRONIC WASTING DISEASE
HYPOTHOSIS AND SPECIFIC AIMS
HYPOTHOSIS
BSE, SCRAPIE, AND CWD, EXPOSED DOMESTIC PIGS ACCUMULATE DIFFERENT QUANTITIES AND STRAINS OF PRIONS IN PERIPHERAL TISSUES, EACH ONE OF THEM WITH PARTICULAR ZOONOTIC POTENTIALS
Final Report – CJD Foundation Grant Program A.
Project Title: Systematic evaluation of the zoonotic potential of different CWD isolates. Principal Investigator: Rodrigo Morales, PhD.
Systematic evaluation of the zoonotic potential of different CWD isolates. Rodrigo Morales, PhD Assistant Professor Protein Misfolding Disorders lab Mitchell Center for Alzheimer’s disease and Related Brain Disorders Department of Neurology University of Texas Health Science Center at Houston Washington DC. July 14th, 2018
Conclusions and Future Directions • We have developed a highly sensitive and specific CWD-PMCA platform to be used as a diagnostic tool. • Current PMCA set up allow us to mimic relevant prion inter-species transmission events. • Polymorphic changes at position 96 of the prion protein apparently alter strain properties and, consequently, the zoonotic potential of CWD isolates. • Inter-species and inter-polymorphic PrPC → PrPSc conversions further increase the spectrum of CWD isolates possibly present in nature. • CWD prions generated in 96SS PrPC substrate apparently have greater inter-species transmission potentials. • Future experiments will explore the zoonotic potential of CWD prions along different adaptation scenarios, including inter-species and inter-polymorphic.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Location: Virus and Prion Research
Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
Author item MOORE, SARAH - Orise Fellow item Kunkle, Robert item KONDRU, NAVEEN - Iowa State University item MANNE, SIREESHA - Iowa State University item SMITH, JODI - Iowa State University item KANTHASAMY, ANUMANTHA - Iowa State University item WEST GREENLEE, M - Iowa State University item Greenlee, Justin Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 3/15/2017 Publication Date: N/A Citation: N/A Interpretive Summary:
Technical Abstract: Aims: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of cervids. We previously demonstrated that disease-associated prion protein (PrPSc) can be detected in the brain and retina from pigs challenged intracranially or orally with the CWD agent. In that study, neurological signs consistent with prion disease were observed only in one pig: an intracranially challenged pig that was euthanized at 64 months post-challenge. The purpose of this study was to use an antigen-capture immunoassay (EIA) and real-time quaking-induced conversion (QuIC) to determine whether PrPSc is present in lymphoid tissues from pigs challenged with the CWD agent.
Methods: At two months of age, crossbred pigs were challenged by the intracranial route (n=20), oral route (n=19), or were left unchallenged (n=9). At approximately 6 months of age, the time at which commercial pigs reach market weight, half of the pigs in each group were culled (<6 month challenge groups). The remaining pigs (>6 month challenge groups) were allowed to incubate for up to 73 months post challenge (mpc). The retropharyngeal lymph node (RPLN) was screened for the presence of PrPSc by EIA and immunohistochemistry (IHC). The RPLN, palatine tonsil, and mesenteric lymph node (MLN) from 6-7 pigs per challenge group were also tested using EIA and QuIC.
Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 oral >6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%).
Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research
Title: The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP
Author item MOORE, S - Orise Fellow item Kokemuller, Robyn item WEST-GREENLEE, M - Iowa State University item BALKEMA-BUSCHMANN, ANNE - Friedrich-Loeffler-institut item GROSCHUP, MARTIN - Friedrich-Loeffler-institut item Greenlee, Justin Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 5/10/2018 Publication Date: 5/22/2018 Citation: Moore, S.J., Kokemuller, R.D., West-Greenlee, M.H., Balkema-Buschmann, A., Groschup, M.H., Greenlee, J.J. 2018. The agent of chronic wasting disease from pigs is infectious in transgenic mice expressing human PRNP. Prion 2018, Santiago de Compostela, Spain, May 22-25, 2018. Paper No. WA15, page 44.
Interpretive Summary:
Technical Abstract: We have previously shown that the chronic wasting disease (CWD) agent from white-tailed deer can be transmitted to domestic pigs via intracranial or oral inoculation although with low attack rates and restricted PrPSc accumulation. The objective of this study was to assess the potential for cross-species transmission of pig-passaged CWD using bioassay in transgenic mice. Transgenic mice expressing human (Tg40), bovine (TgBovXV) or porcine (Tg002) PRNP were inoculated intracranially with 1% brain homogenate from a pig that had been intracranially inoculated with a pool of CWD from white-tailed deer. This pig developed neurological clinical signs, was euthanized at 64 months post-inoculation, and PrPSc was detected in the brain. Mice were monitored daily for clinical signs of disease until the end of the study. Mice were considered positive if PrPSc was detected in the brain using an enzyme immunoassay (EIA). In transgenic mice expressing porcine prion protein the average incubation period was 167 days post-inoculation (dpi) and 3/27 mice were EIA positive (attack rate = 11%). All 3 mice were found dead and clinical signs were not noted prior to death. One transgenic mouse expressing bovine prion protein was euthanized due to excessive scratching at 617 dpi and 2 mice culled at the end of the study at 700 dpi were EIA positive resulting in an overall attack rate of 3/16 (19%). None of the transgenic mice expressing human prion protein that died or were euthanized up to 769 dpi were EIA positive and at study end point at 800 dpi 2 mice had positive EIA results (overall attack rate = 2/20 = 10%). The EIA optical density (OD) readings for all positive mice were at the lower end of the reference range (positive mice range, OD = 0.266-0.438; test positive reference range, OD = 0.250-4.000). To the authors’ knowledge, cervid-derived CWD isolates have not been successfully transmitted to transgenic mice expressing human prion protein. The successful transmission of pig-passaged CWD to Tg40 mice reported here suggests that passage of the CWD agent through pigs results in a change of the transmission characteristics which reduces the transmission barrier of Tg40 mice to the CWD agent. If this biological behavior is recapitulated in the original host species, passage of the CWD agent through pigs could potentially lead to increased pathogenicity of the CWD agent in humans.
cwd scrapie pigs oral routes
***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <***
>*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health. <***
***> Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 oral >6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%).
***> Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
snip.....
In the USA, under the Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law. Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES.
It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
snip.....
36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011). The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE). Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison. snip..... The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
snip.....
In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion. snip..... In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible... For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
snip.....
Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
snip.....
***> READ THIS VERY, VERY, CAREFULLY, AUGUST 1997 MAD COW FEED BAN WAS A SHAM, AS I HAVE STATED SINCE 1997! 3 FAILSAFES THE FDA ET AL PREACHED AS IF IT WERE THE GOSPEL, IN TERMS OF MAD COW BSE DISEASE IN USA, AND WHY IT IS/WAS/NOT A PROBLEM FOR THE USA, and those are;
BSE TESTING (failed terribly and proven to be a sham)
BSE SURVEILLANCE (failed terribly and proven to be a sham)
BSE 589.2001 FEED REGULATIONS (another colossal failure, and proven to be a sham)
these are facts folks. trump et al just admitted it with the feed ban.
see;
FDA Reports on VFD Compliance
John Maday
August 30, 2019 09:46 AM VFD-Form 007 (640x427)
Before and after the current Veterinary Feed Directive rules took full effect in January, 2017, the FDA focused primarily on education and outreach. ( John Maday ) Before and after the current Veterinary Feed Directive (VFD) rules took full effect in January, 2017, the FDA focused primarily on education and outreach to help feed mills, veterinarians and producers understand and comply with the requirements. Since then, FDA has gradually increased the number of VFD inspections and initiated enforcement actions when necessary. On August 29, FDA released its first report on inspection and compliance activities. The report, titled “Summary Assessment of Veterinary Feed Directive Compliance Activities Conducted in Fiscal Years 2016 – 2018,” is available online.
SUNDAY, SEPTEMBER 1, 2019
***> FDA Reports on VFD Compliance
***> CWD TO PIGS <***
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Location: Virus and Prion Research
Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
Author item Moore, Sarah item Kunkle, Robert item Kondru, Naveen item Manne, Sireesha item Smith, Jodi item Kanthasamy, Anumantha item West Greenlee, M item Greenlee, Justin
Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 3/15/2017 Publication Date: N/A Citation: N/A Interpretive Summary:
Technical Abstract: Aims: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of cervids. We previously demonstrated that disease-associated prion protein (PrPSc) can be detected in the brain and retina from pigs challenged intracranially or orally with the CWD agent. In that study, neurological signs consistent with prion disease were observed only in one pig: an intracranially challenged pig that was euthanized at 64 months post-challenge. The purpose of this study was to use an antigen-capture immunoassay (EIA) and real-time quaking-induced conversion (QuIC) to determine whether PrPSc is present in lymphoid tissues from pigs challenged with the CWD agent.
Methods: At two months of age, crossbred pigs were challenged by the intracranial route (n=20), oral route (n=19), or were left unchallenged (n=9). At approximately 6 months of age, the time at which commercial pigs reach market weight, half of the pigs in each group were culled (<6 month challenge groups). The remaining pigs (>6 month challenge groups) were allowed to incubate for up to 73 months post challenge (mpc). The retropharyngeal lymph node (RPLN) was screened for the presence of PrPSc by EIA and immunohistochemistry (IHC). The RPLN, palatine tonsil, and mesenteric lymph node (MLN) from 6-7 pigs per challenge group were also tested using EIA and QuIC.
Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 oral >6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%). Conclusions:
This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge.
CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease.
Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
cwd scrapie pigs oral routes
***> However, at 51 months of incubation or greater, 5 animals were positive by one or more diagnostic methods. Furthermore, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study) suggesting that swine are potential hosts for the agent of scrapie. <***
>*** Although the current U.S. feed ban is based on keeping tissues from TSE infected cattle from contaminating animal feed, swine rations in the U.S. could contain animal derived components including materials from scrapie infected sheep and goats. These results indicating the susceptibility of pigs to sheep scrapie, coupled with the limitations of the current feed ban, indicates that a revision of the feed ban may be necessary to protect swine production and potentially human health. <***
***> Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 month group was positive by EIA. PrPSc was detected by QuIC in at least one of the lymphoid tissues examined in 5/6 pigs in the intracranial <6 months group, 6/7 intracranial >6 months group, 5/6 pigs in the oral <6 months group, and 4/6 oral >6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%).
***> Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
CONFIDENTIAL
EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY
While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle. ...
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action.
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....
snip...see much more here ;
FRIDAY, APRIL 20, 2018
*** Scrapie Transmits To Pigs By Oral Route, what about the terribly flawed USA tse prion feed ban?
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies
WEDNESDAY, APRIL 05, 2017
Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
WEDNESDAY, APRIL 05, 2017
*** Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease ***
PRION 2016 CONFERENCE TOKYO
IL-13 Transmission of prions to non human-primates: Implications for human populations
Jean-Philippe Deslys, Emmanuel E. Comoy
CEW, Institute of Emerging Diseases and Innovative Therapies (iMETI), Division of Prions and Related Diseases (SEPIA), Fontenay-aux-Roses, France
Prion diseases are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal prion disease might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, prion diseases, like the other proteinopathies, are reputed to occur spontaneously (atypical animal prion strains, sporadic CJD summing 80 % of human prion cases).
Non-human primate models provided the first evidences supporting the transmissibility of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health1, according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the risk of primary (oral) and secondary (transfusional) risk of BSE, and also the zoonotic potential of other animal prion diseases from bovine, ovine and cervid origins even after very long silent incubation periods.
We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period, with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold' . longer incubation than BSE2. Scrapie, as recently evoked in humanized mice3, is the third potentially zoonotic prion disease (with BSE and L-type BSE4), thus questioning the origin of human sporadic cases. We also observed hidden prions transmitted by blood transfusion in primate which escape to the classical diagnostic methods and extend the field of healthy carriers. We will present an updated panorama of our different long-term transmission studies and discuss the implications on risk assessment of animal prion diseases for human health and of the status of healthy carrier5.
1. Chen, C. C. & Wang, Y. H. Estimation of the Exposure of the UK Population to the Bovine Spongiform Encephalopathy Agent through Dietary Intake During the Period 1980 to 1996. PLoS One 9, e94020 (2014).
2. Comoy, E. E. et al. Transmission of scrapie prions to primate after an extended silent incubation period. Sci Rep 5, 11573 (2015).
3. Cassard, H. et al. Evidence for zoonotic potential of ovine scrapie prions. Nat Commun 5, 5821-5830 (2014).
4. Comoy, E. E. et al. Atypical BSE (BASE) transmitted from asymptomatic aging cattle to a primate. PLoS One 3, e3017 (2008).
5. Gill O. N. et al. Prevalent abnormal prion protein in human appendixes after bovine spongiform encephalopathy epizootic: large scale survey. BMJ. 347, f5675 (2013).
Curriculum Vitae
Dr. Deslys co-authored more than one hundred publications in international scientific journals on main aspects of applied prion research (diagnostic, decontamination techniques, risk assessment, and therapeutic approaches in different experimental models) and on underlying pathological mechanisms. He studied the genetic of the first cases of iatrogenic CJD in France. His work has led to several patents including the BSE (Bovine Spongiform Encephalopathy) diagnostic test most widely used worldwide. He also wrote a book on mad cow disease which can be downloaded here for free (http://www.neuroprion.org/pdf_docs/documentation/madcow_deslys.pdf). His research group is Associate Laboratory to National Reference Laboratory for CJD in France and has high security level microbiological installations (NeuroPrion research platform) with different experimental models (mouse, hamster, macaque). The primate model of BSE developed by his group with cynomolgus macaques turned out to mimick remarkably well the human situation and allows to assess the primary (oral) and secondary (transfusional) risks linked to animal and human prions even after very long silent incubation periods. For several years, his interest has extended to the connections between PrP and Alzheimer and the prion mechanisms underlying neurodegenerative diseases. He is coordinating the NeuroPrion international association (initially european network of excellence now open to all prion researchers).
- 59-
P-088 Transmission of experimental CH1641-like scrapie to bovine PrP overexpression mice
Kohtaro Miyazawa1, Kentaro Masujin1, Hiroyuki Okada1, Yuichi Matsuura1, Takashi Yokoyama2
1Influenza and Prion Disease Research Center, National Institute of Animal Health, NARO, Japan; 2Department of Planning and General Administration, National Institute of Animal Health, NARO
Introduction: Scrapie is a prion disease in sheep and goats. CH1641-lke scrapie is characterized by a lower molecular mass of the unglycosylated form of abnormal prion protein (PrpSc) compared to that of classical scrapie. It is worthy of attention because of the biochemical similarities of the Prpsc from CH1641-like and BSE affected sheep. We have reported that experimental CH1641-like scrapie is transmissible to bovine PrP overexpression (TgBoPrP) mice (Yokoyama et al. 2010). We report here the further details of this transmission study and compare the biological and biochemical properties to those of classical scrapie affected TgBoPrP mice.
Methods: The details of sheep brain homogenates used in this study are described in our previous report (Yokoyama et al. 2010). TgBoPrP mice were intracerebrally inoculated with a 10% brain homogenate of each scrapie strain. The brains of mice were subjected to histopathological and biochemical analyses.
Results: Prpsc banding pattern of CH1641-like scrapie affected TgBoPrP mice was similar to that of classical scrapie affected mice. Mean survival period of CH1641-like scrapie affected TgBoPrP mice was 170 days at the 3rd passage and it was significantly shorter than that of classical scrapie affected mice (439 days). Lesion profiles and Prpsc distributions in the brains also differed between CH1641-like and classical scrapie affected mice.
Conclusion: We succeeded in stable transmission of CH1641-like scrapie to TgBoPrP mice. Our transmission study demonstrates that CH 1641-like scrapie is likely to be more virulent than classical scrapie in cattle.
WS-02
Scrapie in swine: A diagnostic challenge
Justin J Greenlee1, Robert A Kunkle1, Jodi D Smith1, Heather W. Greenlee2
1National Animal Disease Center, US Dept. of Agriculture, Agricultural Research Service, United States; 2Iowa State University College of Veterinary Medicine
A naturally occurring prion disease has not been recognized in swine, but the agent of bovine spongiform encephalopathy does transmit to swine by experimental routes. Swine are thought to have a robust species barrier when exposed to the naturally occurring prion diseases of other species, but the susceptibility of swine to the agent of sheep scrapie has not been thoroughly tested.
Since swine can be fed rations containing ruminant derived components in the United States and many other countries, we conducted this experiment to test the susceptibility of swine to U.S. scrapie isolates by intracranial and oral inoculation. Scrapie inoculum was a pooled 10% (w/v) homogenate derived from the brains of clinically ill sheep from the 4th passage of a serial passage study of the U.S scrapie agent (No. 13-7) through susceptible sheep that were homozygous ARQ at prion protein residues 136, 154, and 171, respectively. Pigs were inoculated intracranially (n=19) with a single 0.75 ml dose or orally (n=24) with 15 ml repeated on 4 consecutive days. Necropsies were done on a subset of animals at approximately six months post inoculation (PI), at the time the pigs were expected to reach market weight. Remaining pigs were maintained and monitored for clinical signs of TSE until study termination at 80 months PI or when removed due to intercurrent disease (primarily lameness). Brain samples were examined by immunohistochemistry (IHC), western blot (WB), and enzyme-linked immunosorbent assay (ELISA). Brain tissue from a subset of pigs in each inoculation group was used for bioassay in mice expressing porcine PRNP.
At six-months PI, no evidence of scrapie infection was noted by any diagnostic method. However, at 51 months of incubation or greater, 5 animals were positive by one or more methods: IHC (n=4), WB (n=3), or ELISA (n=5). Interestingly, positive bioassay results were obtained from all inoculated groups (oral and intracranial; market weight and end of study).
Swine inoculated with the agent of scrapie by the intracranial and oral routes do not accumulate abnormal prion protein (PrPSc) to a level detectable by IHC or WB by the time they reach typical market age and weight. However, strong support for the fact that swine are potential hosts for the agent of scrapie comes from positive bioassay from both intracranially and orally inoculated pigs and multiple diagnostic methods demonstrating abnormal prion protein in intracranially inoculated pigs with long incubation times.
Curriculum Vitae
Dr. Greenlee is Research Veterinary Medical Officer in the Virus and Prion Research Unit at the National Animal Disease Center, US Department of Agriculture, Agricultural Research Service. He applies his specialty in veterinary anatomic pathology to focused research on the intra- and interspecies transmission of prion diseases in livestock and the development of antemortem diagnostic assays for prion diseases. In addition, knockout and transgenic mouse models are used to complement ongoing experiments in livestock species. Dr. Greenlee has publications in a number of topic areas including prion agent decontamination, effects of PRNP genotype on susceptibility to the agent of sheep scrapie, characterization of US scrapie strains, transmission of chronic wasting disease to cervids and cattle, features of H-BSE associated with the E211 K polymorphism, and the development of retinal assessment for antemortem screening for prion diseases in sheep and cattle. Dr. Greenlee obtained his DVM degree and completed the PhD/residency program in Veterinary Pathology at Iowa State University. He is a Diplomate of the American College of Veterinary Pathologists.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Comparison of two US sheep scrapie isolates supports identification as separate strains
Authors
item Moore, Sarah - item Smith, Jodi item West Greenlee, Mary - item Nicholson, Eric item Richt, Juergen item Greenlee, Justin
Submitted to: Veterinary Pathology Publication Type: Peer Reviewed Journal Publication Acceptance Date: December 22, 2015 Publication Date: N/A
Interpretive Summary: Scrapie is a fatal disease of sheep and goats that causes damaging changes in the brain. The infectious agent is an abnormal protein called a prion that has misfolded from its normal state. Whether or not a sheep will get scrapie is determined primarily by their genetics. Furthermore, different scrapie strains exist that may result in a different expression of disease such as shorter incubation periods, unusual clinical signs, or unique patterns of lesions within the brain. This study evaluated two U.S. scrapie isolates in groups of sheep with varying susceptibilities to scrapie. Our data indicates that there are differences in incubation periods, sheep genotype susceptibilities, and lesion profiles that support designating these scrapie isolates as unique strains. The identification of a new scrapie strain in the United States means that control measures, methods of decontamination, and the potential for transmission to other species may need to be reevaluated. This information is useful to sheep farmers and breeders that are selectively breeding animals with genotypes resistant to the most prevalent strain of scrapie and could impact future regulations for the control of scrapie in the United States. Technical Abstract: Scrapie is a naturally occurring transmissible spongiform encephalopathy (TSE) of sheep and goats. There are different strains of sheep scrapie that are associated with unique molecular, transmission, and phenotype characteristics, but very little is known about the potential presence of scrapie strains within sheep in the US. Scrapie strain and PRNP genotype could both affect susceptibility, potential for transmission, incubation period, and control measures required for eliminating scrapie from a flock. Here we evaluate two US scrapie isolates, No. 13-7 and x124, after intranasal inoculation to compare clinical signs, incubation periods (IP), spongiform lesions, and patterns of PrPSc deposition in sheep with scrapie-susceptible PRNP genotypes (QQ171). After inoculation with x124, susceptibility and IP were associated with valine at codon 136 (V136) of the prion protein: VV136 had short IPs (6.9 months), AV136 sheep were 11.9 months, and AA136 sheep did not develop scrapie. All No.13-7 inoculated sheep developed scrapie with IP’s of 20.1 months for AA136 sheep, 22.8 months for AV136 sheep, and 26.7 months for VV136 sheep. Patterns of immunoreactivity in the brain were influenced by challenge isolate and host genotype. Differences in PrPSc profiles versus isolate were most striking when examining brains from sheep with the VV136 genotype. In summary, intranasal inoculation with isolates x124 and No. 13-7 resulted in differences in IP, sheep genotype susceptibility, and PrPSc profile that support designation as separate strains.
Last Modified: 6/6/2016
31
Appendix I VISIT TO USA - OR A E WRATHALL — INFO ON BSE AND SCRAPIE
Dr Clark lately of the scrapie Research Unit, Mission Texas has
successfully transmitted ovine and caprine scrapie to cattle. The
experimental results have not been published but there are plans to do
this. This work was initiated in 1978. A summary of it is:-
Expt A 6 Her x Jer calves born in 1978 were inoculated as follows with
a 2nd Suffolk scrapie passage:-
i/c 1ml; i/m, 5ml; s/c 5ml; oral 30ml.
1/6 went down after 48 months with a scrapie/BSE-like disease.
Expt B 6 Her or Jer or HxJ calves were inoculated with angora Goat
virus 2/6 went down similarly after 36 months.
Expt C Mice inoculated from brains of calves/cattle in expts A & B were resistant, only 1/20 going down with scrapie and this was the reason given for not publishing.
Diagnosis in A, B, C was by histopath. No reports on SAF were given.
Dr Warren Foote indicated success so far in eliminating scrapie in offspring from experimentally— (and naturally) infected sheep by ET. He had found difficulty in obtaining embryos from naturally infected sheep (cf SPA).
Prof. A Robertson gave a brief accout of BSE. The us approach was to
32
accord it a very low profile indeed. Dr A Thiermann showed the picture in the "Independent" with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs.
BSE was not reported in USA.
4. Scrapie incidents (ie affected flocks) have shown a dramatic increase since 1978. In 1953 when the National Control scheme was started there were 10-14 incidents, in 1978 - 1 and in 1988 so far 60.
5. Scrapie agent was reported to have been isolated from a solitary fetus.
6. A western blotting diagnostic technique (? on PrP) shows some promise.
7. Results of a questionnaire sent to 33 states on the subject of the national sheep scrapie programme survey indicated
17/33 wished to drop it
6/33 wished to develop it
8/33 had few sheep and were neutral
Information obtained from Dr Wrathall‘s notes of a meeting of the u.s.
Animal Health Association at Little Rock, Arkansas Nov. 1988.
33
In Confidence - Perceptions of unconventional slow virus diseases of animals in the USA - APRIL-MAY 1989 - G A H Wells
3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs. ...
also see hand written notes ;
Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle
Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.
snip...
The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...
EVIDENCE OF SCRAPIE IN SHEEP AS A RESULT OF FOOD BORNE EXPOSURE
This is provided by the statistically significant increase in the incidence of sheep scrape from 1985, as determined from analyses of the submissions made to VI Centres, and from individual case and flock incident studies. ........
RISK OF BSE TO SHEEP VIA FEED
OPII-1
Disease incidence and incubation period of BSE and CH1641 in sheep is associated with PrP gene polymorphisms.
Goldman WI, Hunter N., Benson G., Foster J. and Hope J. AFRC&MRC Neuropathogenesis Unit, Institute for Animal Health, West Mains Rd. Edinburgh EH9 3JF. U.K.
The relative survival periods of mice with different Sine genotype have long been used for scrapie strain typing. The PrP protein. a key molecule in the pathogenesis of scrapie and related diseases, is a product of the Sine locus and homologous proteins are also linked to disease-incidence loci in sheep and man. In sheep alleles of this locus (Sip) encode several PrP protein variants, of which one has been associated with short incubation periods of Cheviot sheep infected with SSBP/1 scrapie. Other isolates, i.e. BSE or CH1641. cause a different pattern of incubation periods and a lower disease incidence in the same flock of Cheviot sheep. Using transmission to sheep of known PrP genotype as our criterion for agent strain typing. we have found a link between BSE and CH1641. a C-group strain of scrapie. Disease susceptibility of sheep to these isolates is associated with different PrP genotypes compared to SSBP/1 scrapie.
OPII –2
Transmission of Bovine Spongiform Encephalopathy in sheep, goats and mice.
Foster J., Hope J., McConnell I. and Fraser H. Institute for Animal Health, AFRC and MRC Neuropathogenesis Unit, Kings Buildings, West Mains Road, Edinburgh EH9 3JF
Bovine Spongiform Encephalopathy (BSE) has been transmitted in two lines of genetically selected sheep [differing in their susceptibilities to the SSBP/1 source of scrapie), and to goats by intracerebral injection and by oral dosing. Incubation periods in sheep for both routes of challenge ranged from 440-994 days. In goats this range was 506-1508 days. Both routes of infection in sheep and goats were almost equally efficient. In mice, primary transmission of BSE identified a sinc-independant genetic control of incubation period. Also, intermediate passage of BSE in sheep or goats did not alter these primary transmission properties. Hamsters were susceptible to BSE only after intervening passage through mice.
Wednesday, January 18, 2012
BSE IN GOATS CAN BE MISTAKEN FOR SCRAPIE
February 1, 2012
Wednesday, January 18, 2012
Selection of Distinct Strain Phenotypes in Mice Infected by Ovine Natural Scrapie Isolates Similar to CH1641 Experimental Scrapie
Journal of Neuropathology & Experimental Neurology:
February 2012 - Volume 71 - Issue 2 - p 140–147
Scrapie-like disorder in a Nyala (Tragelaphus angasi)
IN CONFIDENCE
Spongiform encephalopathy has so far only been recorded in the sheep and goat, man, mink, and several deer including the mule deer, black tailed deer and the elk (most, if not all, of the deer incidents occurred in wild life parts in Wyoming and Colorado). Clinical cases in deer all occurred from 3 1/2 to 5 years old and usually 60-80% losses occurred over a 4 year period...
The clinical and neuropathological findings in F22 are consistent with the spongiform encephalopathies of animals and man. The agents causing spongiform encephalopathy in various species cannot be unequivocally distinguished and some isolates of human agent cause neurologic disease in goats indistinguishable from scrapie. The spongiform encephalopathies are invariably fatal once clinical signs of disease are evident and as very high fatality rates (79% of 67 animals) are recorded in Mule deer it is important that an awareness of the disease is maintained at Marwell.
STRICTLY IN CONFIDENCE
EXTRACT FROM MINUTES OF SCIENTIFIC COMMITTEE MEETING HELD ON 29 SEPTEMBER 1994
BSE: S33/94
a) Sampling of Ruminant Feeding stuffs for Ruminant Protein:
The voluntary sampling‘ on farms with suspected cases of BSE had commenced on 1 July 1994. The ELISA technique detected the presence of ruminant meat and bone meal to a level of 0.25% in finished feeding stuffs. MAFF had released a pre-publication copy of a paper discussing this technique which had been developed at the VI Centre Luddington. It provided detail of the use of the technique in meat and bone meal. It did not, however, discuss the extension of the assay for use in compound feeding stuffs. At the request of UKASTA, MAFF was looking at making the service commercially available in order for individual compounders to do their own testing. MAFF estimated that the charge for such testing would be £35 per sample (plus VAT).
It was reported that Luddington was carrying out further work in identifying potential sources of interference, from individual raw materials, which might produce a false positive result It was understood that glutens were considered to present a particular problem. During a discussion the Committee suggested that the conditioning temperatures, in different mills, might have varying effects on the breakdown of proteins in animal feeding stuffs.
A number of sites where cross contamination between animal proteins and other types of raw materials might occur were identified. These included not only on-farm but in-store, in the country of origin, in boats, in transport as well as different points within the feed mill. It was noted, however, that it might be counter productive to stress these varying numbers and sites.
Concern was expressed that the MAFF had commenced on-farm testing without necessarily thinking through the consequences for the whole of the agricultural industry. Officials were aware that one course of action open to feed compounders was to stop using meat and bone meal in the manufacture of any feeding stuff. An alternative for the industry was the establishment of ruminant feed only Such a step would only be open to those companies with more than one manufacturing site.
Cont'd/...2
94/9.29/3.1
b)
-2-
A decision by the industry as a whole to stop using meat and bone meal would have cost implications for the whole livestock industry. Not only would there be poorer returns to beef producers but also higher raw material costs for compounders when producing pig and poultry feeding stuffs. There would also be the problem of disposing of the unwanted animal by-products. Thus, it was agreed that whatever the actual consequences the effect o:n the livestock industry as a whole would be very damaging.
Proposed Survey of Past a.nd Present Practices in Members Feed Mills:
A copy of the draft questionnaire was circulated to Committee members “Strictly in Confidence". This was designed to investigate the likelihood that feed produced after the introduction of the ruminant feed ban could have become contaminated with ruminant derived protein and whether the likelihood of contamination had changed over time. In discussing the contents, UKASTA had not given any indication, on behalf of members, that they wanted them to complete the questionnaire when finalised. MAFF had also been made fully aware of UKASTA's concern that information submitted in response to the questionnaire by individual companies might, at some future time, be subpoenaed by a Court. This would be in any case taken against the company by a farmer seeking compensation for BSE in his herd.
The Committee was advised that a member company was still in debate over a case concerning the Fowl Pest outbreak in 1984. Lawyers acting for poultry producers had. submitted subpoenas for relevant Ministry documents. MAFF Legal Department was looking at the papers and aimed to resist the subpoena. However, the outcome of this action would not be known until March 1995. At the very least, it was considered that compounders should not: complete the questionnaire until the outcome of the Fowl Pest discussions were known. It was also reported that another company had been recommended, by its legal advisors, not to complete the questionnaire.
At a scientific level, it was noted that the aim of the CVL was to explain why BABs had occurred. Unfortunately, in the investigations it was necessary to identify the name and address of individual mills on the questionnaire in order to reconcile information on BABs regarding feeding practices on farm. It would not be possible for questionnaires to be sent to the CVL via UKASTA on an anonymous basis. UKASTA was seeking guidance from the Association's solicitors on what powers MAFF might have to require completion of the questionnaire.
It was suggested that whilst the CVL was finalising details of the questionnaire UKASTA should co-operate. Thus members were asked to send to the Secretariat their comments on the contents of the questionnaire by mid-November. Views were particularly required on which questions were difficult and/ or impossible to answer both because they were
Cont'd/...3 94/9.29/3.2
-3-
impractical as well as being able to put individual companies in a vulnerable position. These were to be passed on to the CVL with a request for amendments and/ or detailed responses in time for the Committee to discuss at the December meeting. Members were asked to discuss the questionnaire with as few people as possible because of the sensitive nature of this subject.
Members were also asked to keep the Secretariat informed of the nature of any enquiries which MAFF officials might address to them. It was also noted, by one member company who no longer used meat and bone meal, that since taking such action they had not received any queries from MAFF.
C) Recent Legislation:
The MAFF was implementing the two EU Decisions agreed in May. The ban on the use of mammalian meat and bone meal in ruminant feedingstuffs was to be incorporated into the BSE Order. At the same time the SBO ban was to be extended to cover the thymus and intestines of calves less than six months of age.
The European legislation on the rendering industry introduced a processing time/ temperature combination based on the results of rendering trials which had achieved an 80-fold diminution of the BSE agent. The legislation was not due to be brought into operation until the end of 1994. It was, however, hoped that UK rendering plants could have their processes validated and thus be in compliance with the new legislation by the end of October. Although it was not possible to prove zero infectivity, MAFF considered that adherence to the new standards would be a huge step forward in the control of BSE.
The Ministry was also reviewing the SBO legislation in order to make it more straightforward an.d simple to operate. The Committee also noted that, because of the nature of the material concerned, it would be extremely difficult to enforce the legislation. Concern was expressed, therefore, that the Ministry might just be introducing controls on paper. Effective auditing of the legislation should be introduced; for example by weighing the amount of SBO's collected and comparing this against the number of animals slaughtered.
In the light of all these concerns, the Committee considered that an easy reaction would be for the feed industry to stop using meat and bone meal in the manufacture of any animal feeding stuff. However, whereas this would be relatively painless, if somewhat expensive, for the feed industry, it would have serious repercussions throughout the whole of the livestock industry. It would also beg the question as to why it was safe for humans to eat meat whilst the by-products of the butchery trade that we use to produce meat and bone meal were unsatisfactory for animals.
Cont'd/...4
94/9.29/3.3
-4-
d) Origins of BSE:
A transcript of the Radio 4 interview with Mr. Keith Meldrum, Chief Veterinary Officer, held on 22 September was circulated. This raised the possibility of BSE being of bovine as opposed to ovine origin. Clarification had, therefore, been sought from the CVL. The response was that it was not possible to dismiss the possibility that BSE was bovine in origin. However, it was more difficult to support such a theory given current knowledge whereby the BSE epidemic had seen a sudden increase in numbers in the mid 1980's. It was thus still considered that the epidemic was explained by :-
- High level of sheep numbers in the UK;
- A change in the rendering practices in the late 1970's which permitted infected ovine material to survive the production process;
- The recycling of bovine material in the cattle population.
For BSE to be solely of bovine origin there would have had to have been a high prevalence of infected animals prior to the mid—1980‘s and this was not seen. It was thus possible that there was an element of politics in the comments made by Mr. Meldrum and it was probably no coincidence that a report of possible BSE cases in northern Germany had emerged at about the same time.
Meeting with Minister:
The Committee was advised that if necessary the Association would request
a meeting with the Minister to outline members‘ concerns regarding BSE and associated matters.
94/9.29/3.4
STRICTLY IN CONFIDENCE
1988: Letter entitled ‘Scrapie, Time to take HB Parry Seriously’ (YB88/6.8/4.1)
24. In this letter I stated that BSE had been officially confirmed as a TSE (when much of the veterinary profession still favoured a variety of alternate hypotheses). I also suggested that scrapie should be made a notifiable disease, and drew attention to the work of HB 'James' Parry and the possibility that natural scrapie in sheep might be of genetic origin.
25. I withdrew the letter following advice from Professor Barlow (who as far as I can recall had been contacted by MAFF and the Veterinary Record) that it might not be in my interests to pursue publication at that moment in time.
26. I received a letter from the then editor, Edward Boden, questioning my permission to release the information that BSE was indeed a proven TSE. I had no permission, though was unaware that any was needed, to inform my profession of this urgent and important fact.
snip...
Surveillance for emerging scrapie-like diseases in animals in the UK
36. Working with Gerald Wells and other pathologists from the State Veterinary Service, I was involved with surveillance for neurological disease of animals in the UK. This was with particular reference to surveillance for, and subsequent confirmation of TSEs. During my time of employment, novel TSEs arose in domestic cats and in exotic ungulates in zoological collections. I also became involved in the investigation of a putative TSE in hound packs detected by Robert Higgins.
FSE, and BSE in exotic ungulates published in reviews:
1991 (Wells and McGill) ref 5
7
1992 (Wells and McGill) ref 7
FSE discussed in para 15.
37. Putative TSE in hounds - work started 1990 –(see para 41)
Robert Higgins, a Veterinary Investigation Officer at Thirsk, had been working on a hound survey in 1990. Gerald Wells and I myself received histological sections from this survey along with the accompanying letter (YB90/11.28/1.1) dated November 1990. This letter details spongiform changes found in brains from hunt hounds failing to keep up with the rest of the pack, along with the results of SAF extractions from fresh brain material from these same animals. SAFs were not found in brains unless spongiform changes were also present. The spongiform changes were not pathognomonic (ie. conclusive proof) for prion disease, as they were atypical, being largely present in white matter rather than grey matter in the brain and spinal cord. However, Tony Scott, then head of electron microscopy work on TSEs, had no doubt that these SAFs were genuine and that these hounds therefore must have had a scrapie-like disease. I reviewed all the sections myself (original notes appended) and although the pathology was not typical, I could not exclude the possibility that this was a scrapie-like disorder, as white matter vacuolation is seen in TSEs and Wallerian degeneration was also present in the white matter of the hounds, another feature of scrapie.
38. I reviewed the literature on hound neuropathology, and discovered that micrographs and descriptive neuropathology from papers on ‘hound ataxia’ mirrored those in material from Robert Higgins’ hound survey. Dr Tony Palmer (Cambridge) had done much of this work, and I obtained original sections from hound ataxia cases from him. This enabled me provisionally to conclude that Robert Higgins had in all probability detected hound ataxia, but also that hound ataxia itself was possibly a TSE. Gerald Wells confirmed in ‘blind’ examination of single restricted microscopic fields that there was no distinction between the white matter vacuolation present in BSE and scrapie cases, and that occurring in hound ataxia and the hound survey cases.
39. Hound ataxia had reportedly been occurring since the 1930’s, and a known risk factor for its development was the feeding to hounds of downer cows, and particularly bovine offal. Circumstantial evidence suggests that bovine offal may also be causal in FSE, and TME in mink. Despite the inconclusive nature of the neuropathology, it was clearly evident that this putative canine spongiform encephalopathy merited further investigation.
40. The inconclusive results in hounds were never confirmed, nor was the link with hound ataxia pursued. I telephoned Robert Higgins six years after he first sent the slides to CVL. I was informed that despite his submitting a yearly report to the CVO including the suggestion that the hound work be continued, no further work had been done since 1991. This was surprising, to say the very least.
41. The hound work could have provided valuable evidence that a scrapie-like agent may have been present in cattle offal long before the BSE epidemic was recognised. The MAFF hound survey remains unpublished.
Histopathological support to various other published MAFF experiments
Seriously’ (YB88/6.8/4.1)
HB Parry Seriously’ (YB88/6.8/4.1)
IF the scrapie agent is generated from ovine DNA and thence causes disease in other species, then perhaps, bearing in mind the possible role of scrapie in CJD of humans (Davinpour et al, 1985), scrapie and not BSE should be the notifiable disease.
1: Neuroepidemiology. 1985;4(4):240-9.
Sheep consumption: a possible source of spongiform encephalopathy in humans.
Davanipour Z, Alter M, Sobel E, Callahan M.
A fatal spongiform encephalopathy of sheep and goats (scrapie) shares many characteristics with Creutzfeldt-Jakob disease (CJD), a similar dementing illness of humans. To investigate the possibility that CJD is acquired by ingestion of contaminated sheep products, we collected information on production, slaughtering practices, and marketing of sheep in Pennsylvania. The study revealed that sheep were usually marketed before central nervous system signs of scrapie are expected to appear; breeds known to be susceptible to the disease were the most common breeds raised in the area; sheep were imported from other states including those with a high frequency of scrapie; use of veterinary services on the sheep farms investigated and, hence, opportunities to detect the disease were limited; sheep producers in the area knew little about scrapie despite the fact that the disease has been reported in the area, and animal organs including sheep organs were sometimes included in processed food. Therefore, it was concluded that in Pennsylvania there are some 'weak links' through which scrapie-infected animals could contaminate human food, and that consumption of these foods could perhaps account for spongiform encephalopathy in humans. The weak links observed are probably not unique to Pennsylvania.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3915057&dopt=Abstract
Thursday, August 20, 2015 Doctor William J. Hadlow
William J. Hadlow Dr. Hadlow (Ohio State ’48), 94, Hamilton, Montana, died June 20, 2015.
Spongiform Encephalopathy in Captive Wild ZOO BSE INQUIRY
spontaneous TSE Prion disease
***>Transmission of scrapie prions to primate after an extended silent incubation period
***>Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.
Like lambs to the slaughter
* 31 March 2001 *
Debora MacKenzie *
Magazine issue 2284
Suspect symptoms
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
Exclusive from New Scientist magazine
Four years ago, Terry Singeltary watched his mother die horribly from a degenerative brain disease. Doctors told him it was Alzheimer's, but Singeltary was suspicious.
The diagnosis didn't fit her violent symptoms, and he demanded an autopsy. It showed she had died of sporadic Creutzfeldt-Jakob disease.
Photo: Murdo McLeod
Most doctors believe that sCJD is caused by a prion protein deforming by chance into a killer. But Singeltary thinks otherwise.
He is one of a number of campaigners who say that some sCJD, like the variant CJD related to BSE, is caused by eating meat from infected animals.
Their suspicions have focused on sheep carrying scrapie, a BSE-like disease that is widespread in flocks across Europe and North America.
Now scientists in France have stumbled across new evidence that adds weight to the campaigners' fears.
To their complete surprise, the researchers found that one strain of scrapie causes the same brain damage in mice as sCJD.
"This means we cannot rule out that at least some sCJD may be caused by some strains of scrapie," says team member Jean-Philippe Deslys of the French Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses, south-west of Paris.
Hans Kretschmar of the University of Göttingen, who coordinates CJD surveillance in Germany, is so concerned by the findings that he now wants to trawl back through past sCJD cases to see if any might have been caused by eating infected mutton or lamb.
Brain damage Scrapie has been around for centuries and until now there has been no evidence that it poses a risk to human health.
But if the French finding means that scrapie can cause sCJD in people, countries around the world may have overlooked a CJD crisis to rival that caused by BSE.
Deslys and colleagues were originally studying vCJD, not sCJD.
They injected the brains of macaque monkeys with brain from BSE cattle, and from French and British vCJD patients. The brain damage and clinical symptoms in the monkeys were the same for all three.
Mice injected with the original sets of brain tissue or with infected monkey brain also developed the same symptoms.
As a control experiment, the team also injected mice with brain tissue from people and animals with other prion diseases: a French case of sCJD; a French patient who caught sCJD from human-derived growth hormone; sheep with a French strain of scrapie; and mice carrying a prion derived from an American scrapie strain.
As expected, they all affected the brain in a different way from BSE and vCJD.
But while the American strain of scrapie caused different damage from sCJD, the French strain produced exactly the same pathology. Multiple strains "The main evidence that scrapie does not affect humans has been epidemiology," says Moira Bruce of the neuropathogenesis unit of the Institute for Animal Health in Edinburgh, who was a member of the same team as Deslys.
"You see about the same incidence of the disease everywhere, whether or not there are many sheep, and in countries such as New Zealand with no scrapie," she says.
In the only previous comparisons of sCJD and scrapie in mice, Bruce found they were dissimilar. But there are more than 20 strains of scrapie, and six of sCJD.
"You would not necessarily see a relationship between the two with epidemiology if only some strains affect only some people," says Deslys.
Bruce is cautious about the mouse results, but agrees they require further investigation.
Other trials of scrapie and sCJD in mice, she says, are in progress.
Deformed proteins People can have three different genetic variations of the human prion protein, and each type of protein can fold up two different ways.
Kretschmar has found that these six combinations correspond to six clinical types of sCJD: each type of normal prion produces a particular pathology when it spontaneously deforms to produce sCJD. But if these proteins deform because of infection with a disease-causing prion, the relationship between pathology and prion type should be different, as it is in vCJD.
"If we look at brain samples from sporadic CJD cases and find some that do not fit the pattern," says Kretschmar, "that could mean they were caused by infection."
There are 250 deaths per year from sCJD in the US, and a similar incidence elsewhere.
Singeltary and other US activists think that some of these people died after eating contaminated meat or "nutritional" pills containing dried animal brain.
Governments will have a hard time facing activists like Singeltary if it turns out that some sCJD isn't as spontaneous as doctors have insisted.
Deslys's work on macaques also provides further proof that the human disease vCJD is caused by BSE.
And the experiments showed that vCJD is much more virulent to primates than BSE, even when injected into the bloodstream rather than the brain. This, says Deslys, means that there is an even bigger risk than we thought that vCJD can be passed from one patient to another through contaminated blood transfusions and surgical instruments.
More at: Proceedings of the National Academy of Sciences (vol 98, p 4142)
Correspondence about this story should be directed to letters@newscientist.com 1900 GMT, 28 March 2001
* New Scientist
http://www.newscientist.com/dailynews/news.jsp?id=ns9999560
http://www.newscientist.com/article.ns?id=mg16922840.300
http://www.newscientist.com/article.ns?id=mg16922840.300
RESEARCH ARTICLE
The emergence of classical BSE from atypical/Nor98 scrapie
Alvina Huor, View ORCID ProfileJuan Carlos Espinosa, View ORCID ProfileEnric Vidal, Hervé Cassard, View ORCID ProfileJean-Yves Douet, Séverine Lugan, Naima Aron, View ORCID ProfileAlba Marín-Moreno, Patricia Lorenzo, Patricia Aguilar-Calvo, Juan Badiola, Rosa Bolea, Martí Pumarola, Sylvie L. Benestad, Leonore Orge, Alana M. Thackray, Raymond Bujdoso, View ORCID ProfileJuan-Maria Torres, and View ORCID ProfileOlivier Andreoletti PNAS December 26, 2019 116 (52) 26853-26862; first published December 16, 2019 https://doi.org/10.1073/pnas.1915737116
Edited by Michael B. A. Oldstone, Scripps Research Institute, La Jolla, CA, and approved November 15, 2019 (received for review September 11, 2019)
Significance
The origin of transmissible BSE in cattle remains unestablished. Sheep scrapie is a potential source of this known zoonotic. Here we investigated the capacity of sheep scrapie to propagate in bovine PrP transgenic mice. Unexpectedly, transmission of atypical but not classical scrapie in bovine PrP mice resulted in propagation of classical BSE prions. Detection of prion seeding activity by in vitro protein misfolding cyclic amplification demonstrated BSE prions in the original atypical scrapie isolates. BSE prion seeding activity was also detected in ovine PrP mice inoculated with limiting dilutions of atypical scrapie. Our data demonstrate that classical BSE prions can emerge during intra- and interspecies passage of atypical scrapie and provide an unprecedented insight into the evolution of mammalian prions.
Abstract
Atypical/Nor98 scrapie (AS) is a prion disease of small ruminants. Currently there are no efficient measures to control this form of prion disease, and, importantly, the zoonotic potential and the risk that AS might represent for other farmed animal species remains largely unknown. In this study, we investigated the capacity of AS to propagate in bovine PrP transgenic mice. Unexpectedly, the transmission of AS isolates originating from 5 different European countries to bovine PrP mice resulted in the propagation of the classical BSE (c-BSE) agent. Detection of prion seeding activity in vitro by protein misfolding cyclic amplification (PMCA) demonstrated that low levels of the c-BSE agent were present in the original AS isolates. C-BSE prion seeding activity was also detected in brain tissue of ovine PrP mice inoculated with limiting dilutions (endpoint titration) of ovine AS isolates. These results are consistent with the emergence and replication of c-BSE prions during the in vivo propagation of AS isolates in the natural host. These data also indicate that c-BSE prions, a known zonotic agent in humans, can emerge as a dominant prion strain during passage of AS between different species. These findings provide an unprecedented insight into the evolution of mammalian prion strain properties triggered by intra- and interspecies passage. From a public health perspective, the presence of c-BSE in AS isolates suggest that cattle exposure to small ruminant tissues and products could lead to new occurrences of c-BSE.
snip...
Our data reported here showed that c-BSE prions are present as a minor variant in natural isolates of ovine AS. In addition, transmission of ovine AS to bovine PrP mice demonstrated that c-BSE can emerge during these transmissions as the dominant prion strain. These results provide a cogent argument in favor of the conformational selection model as the mechanism for prion strain mutation during interspecies prion transmission. This would be expected to occur by selection of a preexisting PrPSc variant in AS isolates, one best suited to the new replicative environment. Within this conceptual framework, the occurrence of prion strain mutation is dependent upon the particular repertoire of PrPSc variants associated with distinct prion strains. This notion is supported by our observation that c-BSE prions emerged during serial transmission of ovine AS in tgBov mice but not from serial passage of classical scrapie in the same mouse line [Table 1 and Cassard et al. (15)].
The diversity of prion strains that exist in small ruminants remains undefined, although it is established that at least 5 different natural ovine prion strains exist, including AS (6, 36⇓⇓–39). According to the conformational selection model, each of these different ovine prion strains is associated with a unique and stable PrPSc conformer and a distinct set of minor variants. The tgBov mouse line has previously been reported to support the propagation of a variety of natural ovine prions, of which several displayed significantly shorter incubation periods than c-BSE (15). Strikingly, in our experiments, the diversity of prion variants in the AS isolates (7 different cases) revealed by the serial passage in tgBov was restricted to the c-BSE agent (Table 1). This consistent emergence of a single prion strain argues against the view that AS prion replication in sheep can randomly generate all of the existing stable PrPSc variants associated with a particular ovine PrPC amino acid sequence. Instead, our data support the view that individual prion strains are associated with a restricted repertoire of stable PrPSc variants in a given host. Whether AS is unique in its ability to generate c-BSE prion particles during its replication process remains to be established.
Classical BSE was first recognized in 1984 and 1985 as a novel prion disease affecting cattle in the United Kingdom (40). Epidemiological data clearly established that the number of cases of c-BSE was amplified by the recycling of infected animal carcasses into cattle feed in the form of meat and bone meal (MBM) (41). Since bovine prion disease had not been recognized in cattle prior to the c-BSE epizootic and the disease is apparently noncontagious between cattle, several hypotheses were proposed to explain its emergence. These range from the spontaneous occurrence of c-BSE in cattle to the passage and adaptation of a prion originating from another species (42, 43). Our studies here that show the presence of c-BSE prions in AS isolates, combined with the demonstrated presence of AS in the United Kingdom long before the appearance of the c-BSE epizootic in cattle, suggests that the recycling of AS cases in MBM might be a source of bovine prion disease (20). In addition to its potential role in the initial emergence of c-BSE in cattle, the presence of c-BSE prions in natural cases of AS has current and direct implications for both the continued risk of this ovine prion disease to other farmed animals and for human exposure risks. The distribution of AS cases are widespread across the world (17⇓–19). A recent retrospective analysis of surveillance data collected over a period exceeding 10 y in the European Union (EU) concluded that the prevalence of detected AS cases has remained relatively stable in the different member states, with between 2 and 6 positive cases per 10,000 tested animals per year. This implies that a substantial number of AS-infected animals could enter either the animal or human food chain each year (44, 45), and each case represents a potential source of exposure to the c-BSE agent for farmed animals (MBM derived from rendered small ruminants) and human consumers (consumption of healthy slaughtered animals), respectively. The epidemiological features of AS within the EU is likely to reflect the situation of the disease in other countries that breed and maintain small ruminants.
In Europe, the c-BSE crisis and the emergence of vCJD resulted in the implementation of a strong and coherent policy (EU regulation 999/2001) aimed at control and eradication of this animal prion disease. The total feed ban on the use of MBM in animal feed and the systematic retrieval from the food chain of ruminant tissues that have the potential to contain high levels of prion infectivity, so-called Specified Risk Material (SRM) measures, were instrumental for control of c-BSE in cattle and prevention of dietary human exposure to these bovine prions (46, 47). As a side effect, these measures also strongly limited the exposure of farmed animals and human consumers to the other TSE agents circulating in farmed animal species, including AS.
With the decline of the c-BSE epizootic in cattle and the combined increase in pressure from industry, EU authorities have begun to consider discontinuing certain TSE control measures. The abrogation of the SRM measures for small ruminants and the partial reauthorization of the use of processed animal protein, formerly known as MBM, in animal feed are part of the EU authorities’ agenda. Our observation of the presence of the c-BSE agent in AS-infected small ruminants suggests that modification of the TSE control measures could result in an increased risk of exposure to c-BSE prions for both animals and humans. Whether or not this exposure will result in further c-BSE transmission in cattle and/or humans remains an open and important question.
Friday, December 14, 2012
DEFRA U.K. What is the risk of Chronic Wasting Disease CWD being introduced into Great Britain? A Qualitative Risk Assessment October 2012
snip...
In the USA, under the Food and Drug Administration's BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system. However, this recommendation is guidance and not a requirement by law.
Animals considered at high risk for CWD include:
1) animals from areas declared to be endemic for CWD and/or to be CWD eradication zones and
2) deer and elk that at some time during the 60-month period prior to slaughter were in a captive herd that contained a CWD-positive animal.
Therefore, in the USA, materials from cervids other than CWD positive animals may be used in animal feed and feed ingredients for non-ruminants.
The amount of animal PAP that is of deer and/or elk origin imported from the USA to GB can not be determined, however, as it is not specified in TRACES. It may constitute a small percentage of the 8412 kilos of non-fish origin processed animal proteins that were imported from US into GB in 2011.
Overall, therefore, it is considered there is a __greater than negligible risk___ that (nonruminant) animal feed and pet food containing deer and/or elk protein is imported into GB.
There is uncertainty associated with this estimate given the lack of data on the amount of deer and/or elk protein possibly being imported in these products.
snip...
36% in 2007 (Almberg et al., 2011). In such areas, population declines of deer of up to 30 to 50% have been observed (Almberg et al., 2011). In areas of Colorado, the prevalence can be as high as 30% (EFSA, 2011).
The clinical signs of CWD in affected adults are weight loss and behavioural changes that can span weeks or months (Williams, 2005). In addition, signs might include excessive salivation, behavioural alterations including a fixed stare and changes in interaction with other animals in the herd, and an altered stance (Williams, 2005). These signs are indistinguishable from cervids experimentally infected with bovine spongiform encephalopathy (BSE).
Given this, if CWD was to be introduced into countries with BSE such as GB, for example, infected deer populations would need to be tested to differentiate if they were infected with CWD or BSE to minimise the risk of BSE entering the human food-chain via affected venison.
snip...
The rate of transmission of CWD has been reported to be as high as 30% and can approach 100% among captive animals in endemic areas (Safar et al., 2008).
snip...
In summary, in endemic areas, there is a medium probability that the soil and surrounding environment is contaminated with CWD prions and in a bioavailable form. In rural areas where CWD has not been reported and deer are present, there is a greater than negligible risk the soil is contaminated with CWD prion.
snip...
In summary, given the volume of tourists, hunters and servicemen moving between GB and North America, the probability of at least one person travelling to/from a CWD affected area and, in doing so, contaminating their clothing, footwear and/or equipment prior to arriving in GB is greater than negligible. For deer hunters, specifically, the risk is likely to be greater given the increased contact with deer and their environment. However, there is significant uncertainty associated with these estimates.
snip...
Therefore, it is considered that farmed and park deer may have a higher probability of exposure to CWD transferred to the environment than wild deer given the restricted habitat range and higher frequency of contact with tourists and returning GB residents.
snip...
TUESDAY, APRIL 18, 2017
*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
TUESDAY, JANUARY 17, 2017
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEEDVIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE 2016 to 2017 BSE TSE PRION
THIS April, 4, 2017 violation of the mad cow 21 CFR 589.2000 OAI is very serious for the great state of Michigan, some 20 years post FDA mad cow feed of August 1997. if would most likely take a FOIA request and a decade of wrangling to find out more.
TUESDAY, JANUARY 17, 2017
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEEDVIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE 2016 to 2017 BSE TSE PRION
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEEDVIOLATIONS OFFICIAL ACTION INDICATED OAI UPDATE 2016 to 2017 BSE TSE PRION
I would kindly like to comment on this FDA BSE/Ruminant Feed Inspections Firms Inventory (excel format)4 format, for reporting these breaches of BSE TSE prion protocols, from the extensive mad cow feed ban warning letters the fda use to put out for each violations. simply put, this excel format sucks, and the FDA et al intentionally made it this difficult to follow the usda fda mad cow follies. this is an intentional format to make it as difficult as possible to follow these breaches of the mad cow TSE prion safety feed protocols. to have absolutely no chronological or numerical order, and to format such violations in a way that they are almost impossible to find, says a lot about just how far the FDA and our fine federal friends will go through to hide these continued violations of the BSE TSE prion mad cow feed ban, and any breaches of protocols there from. once again, the wolf guarding the henhouse $$$
NAI = NO ACTION INDICATED
OAI = OFFICIAL ACTION INDICATED
VAI = VOLUNTARY ACTION INDICATED
RTS = REFERRED TO STATE
OAI (Official Action Indicated) when inspectors find significant objectionable conditions or practices and believe that regulatory sanctions are warranted to address the establishment’s lack of compliance with the regulation. An example of an OAI classification would be findings of manufacturing procedures insufficient to ensure that ruminant feed is not contaminated with prohibited material. Inspectors will promptly re-inspect facilities classified OAI after regulatory sanctions have been applied to determine whether the corrective actions are adequate to address the objectionable conditions.
2016
ONE more thing, please remember, the label does not have to say ''deer ration'' for cervid to be pumped up with. you can get the same ''high protein'' from many sources of high protein feed for animals other than cattle, and feed them to cervid...
Saturday, August 29, 2009
FOIA REQUEST FEED RECALL 2009 Product may have contained prohibited materials Bulk Whole Barley, Recall # V-256-2009
Friday, September 4, 2009
FOIA REQUEST ON FEED RECALL PRODUCT 429,128 lbs. feed for ruminant animals may have been contaminated with prohibited material Recall # V-258-2009
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINES -- CLASS II
___________________________________
PRODUCT
Bulk cattle feed made with recalled Darling’s 85% Blood Meal, Flash Dried, Recall # V-024-2007
CODE
Cattle feed delivered between 01/12/2007 and 01/26/2007
RECALLING FIRM/MANUFACTURER
Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007. Firm initiated recall is ongoing.
REASON
Blood meal used to make cattle feed was recalled because it was cross-contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
42,090 lbs.
DISTRIBUTION
WI ___________________________________
PRODUCT
Custom dairy premix products: MNM ALL PURPOSE Pellet, HILLSIDE/CDL Prot-Buffer Meal, LEE, M.-CLOSE UP PX Pellet, HIGH DESERT/ GHC LACT Meal, TATARKA, M CUST PROT Meal, SUNRIDGE/CDL PROTEIN Blend, LOURENZO, K PVM DAIRY Meal, DOUBLE B DAIRY/GHC LAC Mineral, WEST PIONT/GHC CLOSEUP Mineral, WEST POINT/GHC LACT Meal, JENKS, J/COMPASS PROTEIN Meal, COPPINI – 8# SPECIAL DAIRY Mix, GULICK, L-LACT Meal (Bulk), TRIPLE J – PROTEIN/LACTATION, ROCK CREEK/GHC MILK Mineral, BETTENCOURT/GHC S.SIDE MK-MN, BETTENCOURT #1/GHC MILK MINR, V&C DAIRY/GHC LACT Meal, VEENSTRA, F/GHC LACT Meal, SMUTNY, A-BYPASS ML W/SMARTA, Recall # V-025-2007
CODE
The firm does not utilize a code - only shipping documentation with commodity and weights identified.
RECALLING FIRM/MANUFACTURER
Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007. Firm initiated recall is complete.
REASON
Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
9,997,976 lbs.
DISTRIBUTION
ID and NV
END OF ENFORCEMENT REPORT FOR MARCH 21, 2007
###
Tuesday, April 19, 2016
Docket No. FDA-2013-N-0764 for Animal Feed Regulatory Program Standards Singeltary Comment Submission
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission
Greetings again FDA and Mr. Pritchett et al,
MY comments and source reference of sound science on this very important issue are as follows ;
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission
I kindly wish to once again submit to Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed.
Thank you kindly for allowing me to comment again, ...and again...and again, on a topic so important, why it is 'NON-BINDING' is beyond me.
this should have been finalized and made 'BINDING' or MANDATORY OVER A DECADE AGO.
but here lay the problem, once made 'BINDING' or 'MANDATORY', it is still nothing but ink on paper.
we have had a mad cow feed ban in place since August 1997, and since then, literally 100s of millions of pounds BANNED MAD COW FEED has been sent out to commerce and fed out (see reference materials).
ENFORCEMENT OF SAID BINDING REGULATIONS HAS FAILED US TOO MANY TIMES.
so, in my opinion, any non-binding or voluntary regulations will not work, and to state further, 'BINDING' or MANDATORY regulations will not work unless enforced.
with that said, we know that Chronic Wasting Disease CWD TSE Prion easily transmits to other cervid through the oral route.
the old transmission studies of BSE TSE floored scientist once they figured out what they had, and please don't forget about those mink that were fed 95%+ dead stock downer cow, that all came down with TME. please see ;
It is clear that the designing scientists must also have shared Mr Bradleys surprise at the results because all the dose levels right down to 1 gram triggered infection...snip...see full text Singeltary submission;
Greetings again FDA and Mr. Pritchett et al,
MY comments and source reference of sound science on this very important issue are as follows ;
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission
I kindly wish to once again submit to Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed.
Thank you kindly for allowing me to comment again, ...and again...and again, on a topic so important, why it is 'NON-BINDING' is beyond me.
this should have been finalized and made 'BINDING' or MANDATORY OVER A DECADE AGO.
but here lay the problem, once made 'BINDING' or 'MANDATORY', it is still nothing but ink on paper.
we have had a mad cow feed ban in place since August 1997, and since then, literally 100s of millions of pounds BANNED MAD COW FEED has been sent out to commerce and fed out (see reference materials).
ENFORCEMENT OF SAID BINDING REGULATIONS HAS FAILED US TOO MANY TIMES.
so, in my opinion, any non-binding or voluntary regulations will not work, and to state further, 'BINDING' or MANDATORY regulations will not work unless enforced.
with that said, we know that Chronic Wasting Disease CWD TSE Prion easily transmits to other cervid through the oral route.
the old transmission studies of BSE TSE floored scientist once they figured out what they had, and please don't forget about those mink that were fed 95%+ dead stock downer cow, that all came down with TME. please see ;
It is clear that the designing scientists must also have shared Mr Bradleys surprise at the results because all the dose levels right down to 1 gram triggered infection...snip...see full text Singeltary submission;
NATURE|Vol 457|26 February 2009
> Epidemiological investigations conducted by USDA personnel failed to reveal any evidence of a feed source contaminated with TSE material fed to this animal
LMAO!
BANNED MAD COW FEED IN COMMERCE IN ALABAMA
Date: September 6, 2006 at 7:58 am PST PRODUCT
a) EVSRC Custom dairy feed, Recall # V-130-6;
b) Performance Chick Starter, Recall # V-131-6;
c) Performance Quail Grower, Recall # V-132-6;
d) Performance Pheasant Finisher, Recall # V-133-6.
CODE None RECALLING FIRM/MANUFACTURER Donaldson & Hasenbein/dba J&R Feed Service, Inc., Cullman, AL, by telephone on June 23, 2006 and by letter dated July 19, 2006. Firm initiated recall is complete.
REASON
Dairy and poultry feeds were possibly contaminated with ruminant based protein.
VOLUME OF PRODUCT IN COMMERCE 477.72 tons
DISTRIBUTION AL
______________________________
PRODUCT Bulk custom dairy pre-mixes,
Recall # V-120-6 CODE None RECALLING FIRM/MANUFACTURER Ware Milling Inc., Houston, MS, by telephone on June 23, 2006. Firm initiated recall is complete. REASON Possible contamination of dairy animal feeds with ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 350 tons
DISTRIBUTION AL and MS
______________________________
PRODUCT
a) Tucker Milling, LLC Tm 32% Sinking Fish Grower, #2680-Pellet, 50 lb. bags, Recall # V-121-6;
b) Tucker Milling, LLC #31120, Game Bird Breeder Pellet, 50 lb. bags, Recall # V-122-6;
c) Tucker Milling, LLC #31232 Game Bird Grower, 50 lb. bags, Recall # V-123-6;
d) Tucker Milling, LLC 31227-Crumble, Game Bird Starter, BMD Medicated, 50 lb bags, Recall # V-124-6;
e) Tucker Milling, LLC #31120, Game Bird Breeder, 50 lb bags, Recall # V-125-6;
f) Tucker Milling, LLC #30230, 30 % Turkey Starter, 50 lb bags, Recall # V-126-6;
g) Tucker Milling, LLC #30116, TM Broiler Finisher, 50 lb bags, Recall # V-127-6
CODE All products manufactured from 02/01/2005 until 06/20/2006 RECALLING FIRM/MANUFACTURER Recalling Firm: Tucker Milling LLC, Guntersville, AL, by telephone and visit on June 20, 2006, and by letter on June 23, 2006. Manufacturer: H. J. Baker and Brothers Inc., Stamford, CT. Firm initiated recall is ongoing.
REASON Poultry and fish feeds which were possibly contaminated with ruminant based protein were not labeled as "Do not feed to ruminants".
VOLUME OF PRODUCT IN COMMERCE 7,541-50 lb bags
DISTRIBUTION AL, GA, MS, and TN
END OF ENFORCEMENT REPORT FOR AUGUST 9, 2006
###
Subject: MAD COW FEED RECALL AL AND FL VOLUME OF PRODUCT IN COMMERCE 125 TONS Products manufactured from 02/01/2005 until 06/06/2006
Date: August 6, 2006 at 6:16 pm PST PRODUCT
a) CO-OP 32% Sinking Catfish, Recall # V-100-6;
b) Performance Sheep Pell W/Decox/A/N, medicated, net wt. 50 lbs, Recall # V-101-6;
c) Pro 40% Swine Conc Meal -- 50 lb, Recall # V-102-6;
d) CO-OP 32% Sinking Catfish Food Medicated, Recall # V-103-6;
e) "Big Jim's" BBB Deer Ration, Big Buck Blend, Recall # V-104-6;
f) CO-OP 40% Hog Supplement Medicated Pelleted, Tylosin 100 grams/ton, 50 lb. bag, Recall # V-105-6;
g) Pig Starter Pell II, 18% W/MCDX Medicated 282020, Carbadox -- 0.0055%, Recall # V-106-6;
h) CO-OP STARTER-GROWER CRUMBLES, Complete Feed for Chickens from Hatch to 20 Weeks, Medicated, Bacitracin Methylene Disalicylate, 25 and 50 Lbs, Recall # V-107-6;
i) CO-OP LAYING PELLETS, Complete Feed for Laying Chickens, Recall # 108-6;
j) CO-OP LAYING CRUMBLES, Recall # V-109-6;
k) CO-OP QUAIL FLIGHT CONDITIONER MEDICATED, net wt 50 Lbs, Recall # V-110-6;
l) CO-OP QUAIL STARTER MEDICATED, Net Wt. 50 Lbs, Recall # V-111-6;
m) CO-OP QUAIL GROWER MEDICATED, 50 Lbs, Recall # V-112-6 CODE
Product manufactured from 02/01/2005 until 06/06/2006
RECALLING FIRM/MANUFACTURER Alabama Farmers Cooperative, Inc., Decatur, AL, by telephone, fax, email and visit on June 9, 2006. FDA initiated recall is complete.
REASON Animal and fish feeds which were possibly contaminated with ruminant based protein not labeled as "Do not feed to ruminants".
VOLUME OF PRODUCT IN COMMERCE 125 tons
DISTRIBUTION AL and FL
END OF ENFORCEMENT REPORT FOR AUGUST 2, 2006
###
MAD COW FEED RECALL USA EQUALS 10,878.06 TONS NATIONWIDE Sun Jul 16, 2006 09:22 71.248.128.67
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINE -- CLASS II
______________________________
PRODUCT
a) PRO-LAK, bulk weight, Protein Concentrate for Lactating Dairy Animals, Recall # V-079-6;
b) ProAmino II, FOR PREFRESH AND LACTATING COWS, net weight 50lb (22.6 kg), Recall # V-080-6;
c) PRO-PAK, MARINE & ANIMAL PROTEIN CONCENTRATE FOR USE IN ANIMAL FEED, Recall # V-081-6;
d) Feather Meal, Recall # V-082-6 CODE
a) Bulk
b) None
c) Bulk
d) Bulk
RECALLING FIRM/MANUFACTURER H. J. Baker & Bro., Inc., Albertville, AL, by telephone on June 15, 2006 and by press release on June 16, 2006. Firm initiated recall is ongoing.
REASON
Possible contamination of animal feeds with ruminent derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 10,878.06 tons
DISTRIBUTION Nationwide
END OF ENFORCEMENT REPORT FOR July 12, 2006
###
10,000,000+ LBS. of PROHIBITED BANNED MAD COW FEED I.E. BLOOD LACED MBM IN COMMERCE USA 2007
Date: March 21, 2007 at 2:27 pm PST
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINES -- CLASS II
___________________________________
PRODUCT
Bulk cattle feed made with recalled Darling's 85% Blood Meal, Flash Dried, Recall # V-024-2007
CODE
Cattle feed delivered between 01/12/2007 and 01/26/2007
RECALLING FIRM/MANUFACTURER
Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007.
Firm initiated recall is ongoing.
REASON
Blood meal used to make cattle feed was recalled because it was cross- contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
42,090 lbs.
DISTRIBUTION
WI
___________________________________
PRODUCT
Custom dairy premix products: MNM ALL PURPOSE Pellet, HILLSIDE/CDL Prot- Buffer Meal, LEE, M.-CLOSE UP PX Pellet, HIGH DESERT/ GHC LACT Meal, TATARKA, M CUST PROT Meal, SUNRIDGE/CDL PROTEIN Blend, LOURENZO, K PVM DAIRY Meal, DOUBLE B DAIRY/GHC LAC Mineral, WEST PIONT/GHC CLOSEUP Mineral, WEST POINT/GHC LACT Meal, JENKS, J/COMPASS PROTEIN Meal, COPPINI - 8# SPECIAL DAIRY Mix, GULICK, L-LACT Meal (Bulk), TRIPLE J - PROTEIN/LACTATION, ROCK CREEK/GHC MILK Mineral, BETTENCOURT/GHC S.SIDE MK-MN, BETTENCOURT #1/GHC MILK MINR, V&C DAIRY/GHC LACT Meal, VEENSTRA, F/GHC LACT Meal, SMUTNY, A- BYPASS ML W/SMARTA, Recall # V-025-2007
CODE
The firm does not utilize a code - only shipping documentation with commodity and weights identified.
RECALLING FIRM/MANUFACTURER
Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007. Firm initiated recall is complete.
REASON
Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
9,997,976 lbs.
DISTRIBUTION
ID and NV
END OF ENFORCEMENT REPORT FOR MARCH 21, 2007
Saturday, August 14, 2010
BSE Case Associated with Prion Protein Gene Mutation (g-h-BSEalabama) and VPSPr PRIONPATHY
(see mad cow feed in COMMERCE IN ALABAMA...TSS)
2009 UPDATE ON ALABAMA AND TEXAS MAD COWS 2005 and 2006
H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism:
clinical and pathologic features in wild-type and E211K cattle following intracranial inoculation
H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism: clinical and pathologic features in wild-type and E211K cattle following intracranial inoculation
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism: clinical and pathologic features in wild-type and E211K cattle following intracranial inoculation
Authors
item Moore, Sarah - item West Greenlee, Mary - item Smith, Jodi item Nicholson, Eric item Vrentas, Catherine item Greenlee, Justin
Submitted to: Prion
Publication Type: Abstract Only
Publication Acceptance Date: August 12, 2015
Publication Date: May 25, 2015
Citation: Moore, S.J., West Greenlee, M.H., Smith, J., Nicholson, E., Vrentas, C., Greenlee, J. 2015. H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism: clinical and pathologic features in wild-type and E211K cattle following intracranial inoculation. Prion 2015. p. S5.
Technical Abstract: In 2006 an H-type bovine spongiform encephalopathy (BSE) case was reported in an animal with an unusual polymorphism (E211K) in the prion protein gene. Although the prevalence of this polymorphism is low, cattle carrying the K211 allele are predisposed to rapid onset of H-type BSE when exposed. The purpose of this study was to investigate the phenotype of this BSE strain in wild-type (E211E) and E211K heterozygous cattle. One calf carrying the wild-type allele and one E211K calf were inoculated intracranially with H-type BSE brain homogenate from the US 2006 case that also carried one K211 allelle. In addition, one wild-type calf and one E211K calf were inoculated intracranially with brain homogenate from a US 2003 classical BSE case. All animals succumbed to clinical disease. Survival times for E211K H-type BSE inoculated catttle (10 and 18 months) were shorter than the classical BSE inoculated cattle (both 26 months). Significant changes in retinal function were observed in H-type BSE challenged cattle only. Animals challenged with the same inoculum showed similar severity and neuroanatomical distribution of vacuolation and disease-associated prion protein deposition in the brain, though differences in neuropathology were observed between E211K H-type BSE and classical BSE inoculated animals. Western blot results for brain tissue from challenged animals were consistent with the inoculum strains. This study demonstrates that the phenotype of E211K H-type BSE remains stable when transmitted to cattle without the E211K polymorphism, and exhibits a number of features that differ from classical BSE in both wild-type and E211K cattle.
*** All animals succumbed to clinical disease. Survival times for E211K H-type BSE inoculated catttle (10 and 18 months) were shorter than the classical BSE inoculated cattle (both 26 months). ***
-------- Original Message --------
Subject: re-BSE prions propagate as either variant CJD-like or sporadic CJD
Date: Thu, 28 Nov 2002 10:23:43 -0000
From: "Asante, Emmanuel A" e.asante@ic.ac.uk
To: "'flounder@wt.net'" flounder@wt.net
Dear Terry,
I have been asked by Professor Collinge to respond to your request. I am a Senior Scientist in the MRC Prion Unit and the lead author on the paper. I have attached a pdf copy of the paper for your attention.
Thank you for your interest in the paper.
In respect of your first question, the simple answer is, ***yes. As you will find in the paper, we have managed to associate the alternate phenotype to type 2 PrPSc, the commonest sporadic CJD. It is too early to be able to claim any further sub-classification in respect of Heidenhain variant CJD or Vicky Rimmer's version. It will take further studies, which are on-going, to establish if there are sub-types to our initial finding which we are now reporting. The main point of the paper is that, as well as leading to the expected new variant CJD phenotype, BSE transmission to the 129-methionine genotype can lead to an alternate phenotype which is indistinguishable from type 2 PrPSc.
I hope reading the paper will enlighten you more on the subject. If I can be of any further assistance please to not hesitate to ask. Best wishes.
Emmanuel Asante
< >
____________________________________
Dr. Emmanuel A Asante MRC Prion Unit & Neurogenetics Dept. Imperial College School of Medicine (St. Mary's) Norfolk Place, LONDON W2 1PG Tel: +44 (0)20 7594 3794 Fax: +44 (0)20 7706 3272 email: e.asante@ic.ac.uk (until 9/12/02) New e-mail: e.asante@prion.ucl.ac.uk (active from now)
_________end...TSS___________________
***Our study demonstrates susceptibility of adult cattle to oral transmission of classical BSE. ***
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. ***
P.86: Estimating the risk of transmission of BSE and scrapie to ruminants and humans by protein misfolding cyclic amplification
Morikazu Imamura, Naoko Tabeta, Yoshifumi Iwamaru, and Yuichi Murayama National Institute of Animal Health; Tsukuba, Japan
To assess the risk of the transmission of ruminant prions to ruminants and humans at the molecular level, we investigated the ability of abnormal prion protein (PrPSc) of typical and atypical BSEs (L-type and H-type) and typical scrapie to convert normal prion protein (PrPC) from bovine, ovine, and human to proteinase K-resistant PrPSc-like form (PrPres) using serial protein misfolding cyclic amplification (PMCA).
Six rounds of serial PMCA was performed using 10% brain homogenates from transgenic mice expressing bovine, ovine or human PrPC in combination with PrPSc seed from typical and atypical BSE- or typical scrapie-infected brain homogenates from native host species. In the conventional PMCA, the conversion of PrPC to PrPres was observed only when the species of PrPC source and PrPSc seed matched. However, in the PMCA with supplements (digitonin, synthetic polyA and heparin), both bovine and ovine PrPC were converted by PrPSc from all tested prion strains. On the other hand, human PrPC was converted by PrPSc from typical and H-type BSE in this PMCA condition.
Although these results were not compatible with the previous reports describing the lack of transmissibility of H-type BSE to ovine and human transgenic mice, ***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
================
ull test Singeltary et al PLOS
THURSDAY, JULY 20, 2017
USDA OIE Alabama Atypical L-type BASE Bovine Spongiform Encephalopathy BSE animal feeds for ruminants rule, 21 CFR 589.200
THURSDAY, JUNE 25, 2020
First Report of the Potential Bovine Spongiform Encephalopathy (BSE)-Related Somatic Mutation E211K of the Prion Protein Gene (PRNP) in Cattle
WEDNESDAY, JUNE 10, 2020
Radical Change in Zoonotic Abilities of Atypical BSE Prion Strains as Evidenced by Crossing of Sheep Species Barrier in Transgenic Mice
PRION 2018 CONFERENCE
P98 The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge
Greenlee JJ (1), Moore SJ (1), and West Greenlee MH (2) (1) United States Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Virus and Prion Research Unit, Ames, IA, United States (2) Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, IA, United States.
reading up on this study from Prion 2018 Conference, very important findings ;
***> This study demonstrates that the H-type BSE agent is transmissible by the oronasal route.
***> These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
PRION 2018 CONFERENCE ABSTRACT
WEDNESDAY, OCTOBER 24, 2018
Experimental Infection of Cattle With a Novel Prion Derived From Atypical H-Type Bovine Spongiform Encephalopathy
MONDAY, JANUARY 09, 2017
Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle
CDC Volume 23, Number 2—February 2017
*** Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
*** Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
TUESDAY, AUGUST 28, 2018
USDA finds BSE infection in Florida cow 08/28/18 6:43 PM
http://animalhealthreportpriontse..blogspot.com/2018/08/usda-finds-bse-infection-in-florida-cow.html
WEDNESDAY, AUGUST 29, 2018
USDA Announces Atypical Bovine Spongiform Encephalopathy Detection USDA 08/29/2018 10:00 AM EDT
WEDNESDAY, AUGUST 29, 2018
Transmissible Spongiform Encephalopathy TSE Prion Atypical BSE Confirmed Florida Update USA August 28, 2018
***> P.108: Successful oral challenge of adult cattle with classical BSE
Sandor Dudas1,*, Kristina Santiago-Mateo1, Tammy Pickles1, Catherine Graham2, and Stefanie Czub1 1Canadian Food Inspection Agency; NCAD Lethbridge; Lethbridge, Alberta, Canada; 2Nova Scotia Department of Agriculture; Pathology Laboratory; Truro, Nova Scotia, Canada
Classical Bovine spongiform encephalopathy (C-type BSE) is a feed- and food-borne fatal neurological disease which can be orally transmitted to cattle and humans. Due to the presence of contaminated milk replacer, it is generally assumed that cattle become infected early in life as calves and then succumb to disease as adults. Here we challenged three 14 months old cattle per-orally with 100 grams of C-type BSE brain to investigate age-related susceptibility or resistance. During incubation, the animals were sampled monthly for blood and feces and subjected to standardized testing to identify changes related to neurological disease. At 53 months post exposure, progressive signs of central nervous system disease were observed in these 3 animals, and they were euthanized. Two of the C-BSE animals tested strongly positive using standard BSE rapid tests, however in 1 C-type challenged animal, Prion 2015 Poster Abstracts S67 PrPsc was not detected using rapid tests for BSE. Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.
***Our study demonstrates susceptibility of adult cattle to oral transmission of classical BSE.
We are further examining explanations for the unusual disease presentation in the third challenged animal.
***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
P.86: Estimating the risk of transmission of BSE and scrapie to ruminants and humans by protein misfolding cyclic amplification
Morikazu Imamura, Naoko Tabeta, Yoshifumi Iwamaru, and Yuichi Murayama
National Institute of Animal Health; Tsukuba, Japan
To assess the risk of the transmission of ruminant prions to ruminants and humans at the molecular level, we investigated the ability of abnormal prion protein (PrPSc) of typical and atypical BSEs (L-type and H-type) and typical scrapie to convert normal prion protein (PrPC) from bovine, ovine, and human to proteinase K-resistant PrPSc-like form (PrPres) using serial protein misfolding cyclic amplification (PMCA).
Six rounds of serial PMCA was performed using 10% brain homogenates from transgenic mice expressing bovine, ovine or human PrPC in combination with PrPSc seed from typical and atypical BSE- or typical scrapie-infected brain homogenates from native host species. In the conventional PMCA, the conversion of PrPC to PrPres was observed only when the species of PrPC source and PrPSc seed matched. However, in the PMCA with supplements (digitonin, synthetic polyA and heparin), both bovine and ovine PrPC were converted by PrPSc from all tested prion strains. On the other hand, human PrPC was converted by PrPSc from typical and H-type BSE in this PMCA condition.
Although these results were not compatible with the previous reports describing the lack of transmissibility of H-type BSE to ovine and human transgenic mice, our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.
P.170: Potential detection of oral transmission of H type atypical BSE in cattle using in vitro conversion
***P.170: Potential detection of oral transmission of H type atypical BSE in cattle using in vitro conversion
Sandor Dudas, John G Gray, Renee Clark, and Stefanie Czub Canadian Food Inspection Agency; Lethbridge, AB Canada
Keywords: Atypical BSE, oral transmission, RT-QuIC
The detection of bovine spongiform encephalopathy (BSE) has had a significant negative impact on the cattle industry worldwide. In response, governments took actions to prevent transmission and additional threats to animal health and food safety. While these measures seem to be effective for controlling classical BSE, the more recently discovered atypical BSE has presented a new challenge. To generate data for risk assessment and control measures, we have challenged cattle orally with atypical BSE to determine transmissibility and mis-folded prion (PrPSc) tissue distribution. Upon presentation of clinical symptoms, animals were euthanized and tested for characteristic histopathological changes as well as PrPSc deposition.
The H-type challenged animal displayed vacuolation exclusively in rostral brain areas but the L-type challenged animal showed no evidence thereof. To our surprise, neither of the animals euthanized, which were displaying clinical signs indicative of BSE, showed conclusive mis-folded prion accumulation in the brain or gut using standard molecular or immunohistochemical assays. To confirm presence or absence of prion infectivity, we employed an optimized real-time quaking induced conversion (RT-QuIC) assay developed at the Rocky Mountain Laboratory, Hamilton, USA.
Detection of PrPSc was unsuccessful for brain samples tests from the orally inoculated L type animal using the RT-QuIC. It is possible that these negative results were related to the tissue sampling locations or that type specific optimization is needed to detect PrPSc in this animal. We were however able to consistently detect the presence of mis-folded prions in the brain of the H-type inoculated animal. Considering the negative and inconclusive results with other PrPSc detection methods, positive results using the optimized RT-QuIC suggests the method is extremely sensitive for H-type BSE detection. This may be evidence of the first successful oral transmission of H type atypical BSE in cattle and additional investigation of samples from these animals are ongoing.
Detection of PrPBSE and prion infectivity in the ileal Peyer’s patch of young calves as early as 2 months after oral challenge with classical bovine spongiform encephalopathy
Ivett Ackermann1 , Anne Balkema‑Buschmann1 , Reiner Ulrich2 , Kerstin Tauscher2 , James C. Shawulu1 , Markus Keller1 , Olanrewaju I. Fatola1 , Paul Brown3 and Martin H. Groschup1*
Abstract
In classical bovine spongiform encephalopathy (C-BSE), an orally acquired prion disease of cattle, the ileal Peyer’s patch (IPP) represents the main entry port for the BSE agent. In earlier C-BSE pathogenesis studies, cattle at 4–6 months of age were orally challenged, while there are strong indications that the risk of infection is highest in young animals. In the present study, unweaned calves aged 4–6 weeks were orally challenged to determine the earli‑ est time point at which newly formed PrPBSE and BSE infectivity are detectable in the IPP. For this purpose, calves were culled 1 week as well as 2, 4, 6 and 8 months post-infection (mpi) and IPPs were examined for BSE infectivity using a bovine PrP transgenic mouse bioassay, and for PrPBSE by immunohistochemistry (IHC) and protein misfolding cyclic amplifcation (PMCA) assays. For the frst time, BSE prions were detected in the IPP as early as 2 mpi by transgenic mouse bioassay and PMCA and 4 mpi by IHC in the follicular dendritic cells (FDCs) of the IPP follicles. These data indi‑ cate that BSE prions propagate in the IPP of unweaned calves within 2 months of oral uptake of the agent.
In summary, our study demonstrates for the frst time PrPBSE (by PMCA) and prion infectivity (by mouse bioassay) in the ileal Peyer’s patch (IPP) of young calves as early as 2 months after infection. From 4 mpi nearly all calves showed PrPBSE positive IPP follicles (by IHC), even with PrPBSE accumulation detectable in FDCs in some animals. Finally, our results confrm the IPP as the early port of entry for the BSE agent and a site of initial propagation of PrPBSE and infectivity during the early pathogenesis of the disease. Terefore, our study supports the recommendation to remove the last four metres of the small intestine (distal ileum) at slaughter, as designated by current legal requirements for countries with a controlled BSE risk status, as an essential measure for consumer and public health protection.
A study comparing preclinical cattle infected naturally with BSE to clinically affected cattle either naturally or experimentally infected with BSE by the oral route found the most abundant PrPSc in the brainstem area (39), which is consistent with ascension to the brain from the gut by sympathetic and parasympathetic projections (40). In our experiment, abundant prions were observed in the brainstem of cattle with clinical signs of BSE, which is similar to the amount in their thalamus or midbrain regions. Interestingly, prions in the brainstem of cattle with clinical evidence of BSE seeded the RT-QuIC reactions faster than any other brain region despite the brainstem area having lower EIA OD values (Table 2) in comparison to other brain regions. This suggests that higher concentrations of prions do not necessarily seed the reaction faster. Perhaps prions of the brainstem exist in a preferred conformation for better conversion despite being present in lower concentrations.
snip...
SUNDAY, APRIL 14, 2019
Estimation of prion infectivity in tissues of cattle infected with atypical BSE by real time-quaking induced conversion assay
WEDNESDAY, APRIL 24, 2019
USDA Announces Atypical Bovine Spongiform Encephalopathy Detection Aug 29, 2018 A Review of Science 2019
WEDNESDAY, JULY 31, 2019
The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
O.4.3
Spread of BSE prions in cynomolgus monkeys (Macaca fascicularis) after oral transmission
Edgar Holznagel1, Walter Schulz-Schaeffer2, Barbara Yutzy1, Gerhard Hunsmann3, Johannes Loewer1 1Paul-Ehrlich-Institut, Federal Institute for Sera and Vaccines, Germany; 2Department of Neuropathology, Georg-August University, Göttingen, Germany, 3Department of Virology and Immunology, German Primate Centre, Göttingen, Germany
Background: BSE-infected cynomolgus monkeys represent a relevant animal model to study the pathogenesis of variant Creutzfeldt-Jacob disease (vCJD).
Objectives: To study the spread of BSE prions during the asymptomatic phase of infection in a simian animal model.
Methods: Orally BSE-dosed macaques (n=10) were sacrificed at defined time points during the incubation period and 7 orally BSE-dosed macaques were sacrificed after the onset of clinical signs. Neuronal and non-neuronal tissues were tested for the presence of proteinase-K-resistant prion protein (PrPres) by western immunoblot and by paraffin-embedded tissue (PET) blot technique.
Results: In clinically diseased macaques (5 years p.i. + 6 mo.), PrPres deposits were widely spread in neuronal tissues (including the peripheral sympathetic and parasympathetic nervous system) and in lymphoid tissues including tonsils. In asymptomatic disease carriers, PrPres deposits could be detected in intestinal lymph nodes as early as 1 year p.i., but CNS tissues were negative until 3 – 4 years p.i. Lumbal/sacral segments of the spinal cord and medulla oblongata were PrPres positive as early as 4.1 years p.i., whereas sympathetic trunk and all thoracic/cervical segments of the spinal cord were still negative for PrPres. However, tonsil samples were negative in all asymptomatic cases.
Discussion: There is evidence for an early spread of BSE to the CNS via autonomic fibres of the splanchnic and vagus nerves indicating that trans-synaptical spread may be a time-limiting factor for neuroinvasion. Tonsils were predominantly negative during the main part of the incubation period indicating that epidemiological vCJD screening results based on the detection of PrPres in tonsil biopsies may mostly tend to underestimate the prevalence of vCJD among humans.
P.4.23
Transmission of atypical BSE in humanized mouse models
Liuting Qing1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5, Qingzhong Kong1 1Case Western Reserve University, USA; 2Instituto Zooprofilattico Sperimentale, Italy; 3Friedrich-Loeffler-Institut, Germany; 4National Veterinary Research Institute, Poland; 5Kansas State University (Previously at USDA National Animal Disease Center), USA
Background: Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Atypical BSE cases have been discovered in three continents since 2004; they include the L-type (also named BASE), the H-type, and the first reported case of naturally occurring BSE with mutated bovine PRNP (termed BSE-M). The public health risks posed by atypical BSE were largely undefined.
Objectives: To investigate these atypical BSE types in terms of their transmissibility and phenotypes in humanized mice. Methods: Transgenic mice expressing human PrP were inoculated with several classical (C-type) and atypical (L-, H-, or Mtype) BSE isolates, and the transmission rate, incubation time, characteristics and distribution of PrPSc, symptoms, and histopathology were or will be examined and compared.
Results: Sixty percent of BASE-inoculated humanized mice became infected with minimal spongiosis and an average incubation time of 20-22 months, whereas only one of the C-type BSE-inoculated mice developed prion disease after more than 2 years. Protease-resistant PrPSc in BASE-infected humanized Tg mouse brains was biochemically different from bovine BASE or sCJD. PrPSc was also detected in the spleen of 22% of BASE-infected humanized mice, but not in those infected with sCJD. Secondary transmission of BASE in the humanized mice led to a small reduction in incubation time. The atypical BSE-H strain is also transmissible with distinct phenotypes in the humanized mice, but no BSE-M transmission has been observed so far.
Discussion: Our results demonstrate that BASE is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice.
BSE-H is also transmissible in our humanized Tg mice.
The possibility of more than two atypical BSE strains will be discussed.
Supported by NINDS NS052319, NIA AG14359, and NIH AI 77774.
P03.137
Transmission of BSE to Cynomolgus Macaque, a Non-human Primate; Development of Clinical Symptoms and Tissue Distribution of PrPSC
Yamakawa, Y1; Ono, F2; Tase, N3; Terao, K3; Tannno, J3; Wada, N4; Tobiume, M5; Sato, Y5; Okemoto-Nakamura, Y1; Hagiwara, K1; Sata, T5 1National Institure of Infectious diseases, Cell biology and Biochemistry, Japan; 2Corporation for Production and Research Laboratory Primates., Japan; 3National Institure of Biomedical Innovation, Tsukuba Primate Reserch Center, Japan; 4Yamauchi Univ., Veterinary Medicine, Japan; 5National Institure of Infectious diseases, Pathology, Japan
Two of three cynomolgus monkeys developed abnormal neuronal behavioral signs at 30-(#7) and 28-(#10) months after intracerebral inoculation of 200ul of 10% brain homogenates of BSE affected cattle (BSE/JP6). Around 30 months post inoculation (mpi), they developed sporadic anorexia and hyperekplexia with squeal against environmental stimulations such as light and sound. Tremor, myoclonic jerk and paralysis became conspicuous during 32 to 33-mpi, and symptoms become worsened according to the disease progression. Finally, one monkey (#7) fell into total paralysis at 36-mpi. This monkey was sacrificed at 10 days after intensive veterinary care including infusion and per oral supply of liquid food. The other monkey (#10) had to grasp the cage bars to keep an upright posture caused by the sever ataxia. This monkey was sacrificed at 35-mpi. EEG of both monkeys showed diffuse slowing. PSD characteristic for sporadic CJD was not observed in both monkeys. The result of forearm movement test showed the hypofunction that was observed at onset of clinical symptoms. Their cognitive function determined by finger maze test was maintained at the early stage of sideration. However, it was rapidly impaired followed by the disease progression. Their autopsied tissues were immunochemically investigated for the tissue distribution of PrPSc. Severe spongiform change in the brain together with heavy accumulation of PrPSc having the type 2B/4 glycoform profile confirmed successful transmission of BSE to Cynomolgus macaques. Granular and linear deposition of PrPSC was detected by IHC in the CNS of both monkeys. At cerebral cortex, PrPSC was prominently accumulated in the large plaques. Sparse accumulation of PrPSc was detected in several peripheral nerves of #7 but not in #10 monkey, upon the WB analysis. Neither #7 nor #10 monkey accumulated detectable amounts of PrPSc in their lymphatic organs such as tonsil, spleen, adrenal grands and thymus although PrPSc was barely detected in the submandibular lymph node of #7 monkey. Such confined tissue distribution of PrPSc after intracerebral infection with BSE agent is not compatible to that reported on the Cynomolgus macaques infected with BSE by oral or intra-venous (intra-peritoneal) routs, in which PrPSc was accumulated at not only CNS but also widely distributed lymphatic tissues.
P04.27
Experimental BSE Infection of Non-human Primates: Efficacy of the Oral Route
Holznagel, E1; Yutzy, B1; Deslys, J-P2; Lasmézas, C2; Pocchiari, M3; Ingrosso, L3; Bierke, P4; Schulz-Schaeffer, W5; Motzkus, D6; Hunsmann, G6; Löwer, J1 1Paul-Ehrlich-Institut, Germany; 2Commissariat à l´Energie Atomique, France; 3Instituto Superiore di Sanità, Italy; 4Swedish Institute for Infectious Disease control, Sweden; 5Georg August University, Germany; 6German Primate Center, Germany
Background: In 2001, a study was initiated in primates to assess the risk for humans to contract BSE through contaminated food. For this purpose, BSE brain was titrated in cynomolgus monkeys.
Aims: The primary objective is the determination of the minimal infectious dose (MID50) for oral exposure to BSE in a simian model, and, by in doing this, to assess the risk for humans. Secondly, we aimed at examining the course of the disease to identify possible biomarkers.
Methods: Groups with six monkeys each were orally dosed with lowering amounts of BSE brain: 16g, 5g, 0.5g, 0.05g, and 0.005g. In a second titration study, animals were intracerebrally (i.c.) dosed (50, 5, 0.5, 0.05, and 0.005 mg).
Results: In an ongoing study, a considerable number of high-dosed macaques already developed simian vCJD upon oral or intracerebral exposure or are at the onset of the clinical phase. However, there are differences in the clinical course between orally and intracerebrally infected animals that may influence the detection of biomarkers.
Conclusions: Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate. The difference in the incubation period between 5 g oral and 5 mg i.c. is only 1 year (5 years versus 4 years). However, there are rapid progressors among orally dosed monkeys that develop simian vCJD as fast as intracerebrally inoculated animals.
The work referenced was performed in partial fulfilment of the study “BSE in primates“ supported by the EU (QLK1-2002-01096).http://www.neuroprion.org/resources/pdf_docs/conferences/prion2007/abstract_book.pdf
Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate.
WE know now, and we knew decades ago, that 5.5 grams of suspect feed in TEXAS was enough to kill 100 cows.
look at the table and you'll see that as little as 1 mg (or 0.001 gm) caused 7% (1 of 14) of the cows to come down with BSE;
Risk of oral infection with bovine spongiform encephalopathy agent in primates
Corinne Ida Lasmézas, Emmanuel Comoy, Stephen Hawkins, Christian Herzog, Franck Mouthon, Timm Konold, Frédéric Auvré, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Nicole Salès, Gerald Wells, Paul Brown, Jean-Philippe Deslys Summary The uncertain extent of human exposure to bovine spongiform encephalopathy (BSE)--which can lead to variant Creutzfeldt-Jakob disease (vCJD)--is compounded by incomplete knowledge about the efficiency of oral infection and the magnitude of any bovine-to-human biological barrier to transmission. We therefore investigated oral transmission of BSE to non-human primates. We gave two macaques a 5 g oral dose of brain homogenate from a BSE-infected cow. One macaque developed vCJD-like neurological disease 60 months after exposure, whereas the other remained free of disease at 76 months. On the basis of these findings and data from other studies, we made a preliminary estimate of the food exposure risk for man, which provides additional assurance that existing public health measures can prevent transmission of BSE to man.
snip...
BSE bovine brain inoculum
100 g 10 g 5 g 1 g 100 mg 10 mg 1 mg 0·1 mg 0·01 mg
Primate (oral route)* 1/2 (50%)
Cattle (oral route)* 10/10 (100%) 7/9 (78%) 7/10 (70%) 3/15 (20%) 1/15 (7%) 1/15 (7%)
RIII mice (ic ip route)* 17/18 (94%) 15/17 (88%) 1/14 (7%)
PrPres biochemical detection
The comparison is made on the basis of calibration of the bovine inoculum used in our study with primates against a bovine brain inoculum with a similar PrPres concentration that was inoculated into mice and cattle.8 *Data are number of animals positive/number of animals surviving at the time of clinical onset of disease in the first positive animal (%). The accuracy of bioassays is generally judged to be about plus or minus 1 log. ic ip=intracerebral and intraperitoneal.
Table 1: Comparison of transmission rates in primates and cattle infected orally with similar BSE brain inocula
Published online January 27, 2005
It is clear that the designing scientists must also have shared Mr Bradley’s surprise at the results because all the dose levels right down to 1 gram triggered infection.
it is clear that the designing scientists must have also shared Mr Bradleyâs surprise at the results because all the dose levels right down to 1 gram triggered infection.
I ask Professor Kong ;
Thursday, December 04, 2008 3:37 PM
Subject: RE: re--Chronic Wating Disease (CWD) and Bovine Spongiform Encephalopathies (BSE): Public Health Risk Assessment
IS the h-BSE more virulent than typical BSE as well, or the same as cBSE, or less virulent than cBSE? just curious.....
Professor Kong reply ;
.....snip
As to the H-BSE, we do not have sufficient data to say one way or another, but we have found that H-BSE can infect humans. I hope we could publish these data once the study is complete. Thanks for your interest.
Best regards, Qingzhong Kong, PhD Associate Professor Department of Pathology Case Western Reserve University Cleveland, OH 44106 USA
P.4.23 Transmission of atypical BSE in humanized mouse models
Liuting Qing1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5, Qingzhong Kong1 1Case Western Reserve University, USA; 2Instituto Zooprofilattico Sperimentale, Italy; 3Friedrich-Loeffler-Institut, Germany; 4National Veterinary Research Institute, Poland; 5Kansas State University (Previously at USDA National Animal Disease Center), USA
Background: Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Atypical BSE cases have been discovered in three continents since 2004; they include the L-type (also named BASE), the H-type, and the first reported case of naturally occurring BSE with mutated bovine PRNP (termed BSE-M). The public health risks posed by atypical BSE were argely undefined.
Objectives: To investigate these atypical BSE types in terms of their transmissibility and phenotypes in humanized mice.
Methods: Transgenic mice expressing human PrP were inoculated with several classical (C-type) and atypical (L-, H-, or Mtype) BSE isolates, and the transmission rate, incubation time, characteristics and distribution of PrPSc, symptoms, and histopathology were or will be examined and compared.
Results: Sixty percent of BASE-inoculated humanized mice became infected with minimal spongiosis and an average incubation time of 20-22 months, whereas only one of the C-type BSE-inoculated mice developed prion disease after more than 2 years. Protease-resistant PrPSc in BASE-infected humanized Tg mouse brains was biochemically different from bovine BASE or sCJD. PrPSc was also detected in the spleen of 22% of BASE-infected humanized mice, but not in those infected with sCJD. Secondary transmission of BASE in the humanized mice led to a small reduction in incubation time. The atypical BSE-H strain is also transmissible with distinct phenotypes in the humanized mice, but no BSE-M transmission has been observed so far.
Discussion: Our results demonstrate that BASE is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice. BSE-H is also transmissible in our humanized Tg mice. The possibility of more than two atypical BSE strains will be discussed.
Supported by NINDS NS052319, NIA AG14359, and NIH AI 77774.
see full text ;
The 2004 enhanced BSE surveillance program was so flawed, that one of the top TSE prion Scientist for the CDC, Dr. Paul Brown stated ; Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive.
see ;
CDC - Bovine Spongiform Encephalopathy and Variant Creutzfeldt ... Dr. Paul Brown is Senior Research Scientist in the Laboratory of Central Nervous System ... Address for correspondence: Paul Brown, Building 36, Room 4A-05, ...
PAUL BROWN COMMENT TO ME ON THIS ISSUE
Tuesday, September 12, 2006 11:10 AM
"Actually, Terry, I have been critical of the USDA handling of the mad cow issue for some years, and with Linda Detwiler and others sent lengthy detailed critiques and recommendations to both the USDA and the Canadian Food Agency."
OR, what the Honorable Phyllis Fong of the OIG found ;
Finding 2 Inherent Challenges in Identifying and Testing High-Risk Cattle Still Remain
IT is of my opinion, that the OIE and the USDA et al, are the soul reason, and responsible parties, for Transmissible Spongiform Encephalopathy TSE prion diseases, including typical and atypical BSE, typical and atypical Scrapie, and all strains of CWD, and human TSE there from, spreading around the globe. I have lost all confidence of this organization as a regulatory authority on animal disease, and consider it nothing more than a National Trading Brokerage for all strains of animal TSE, just to satisfy there commodity. AS i said before, OIE should hang up there jock strap now, since it appears they will buckle every time a country makes some political hay about trade protocol, commodities and futures. IF they are not going to be science based, they should do everyone a favor and dissolve there organization. JUST because of low documented human body count with nvCJD and the long incubation periods, the lack of sound science being replaced by political and corporate science in relations with the fact that science has now linked some sporadic CJD with atypical BSE and atypical scrapie, and the very real threat of CWD being zoonosis, I believed the O.I.E. has failed terribly and again, I call for this organization to be dissolved...
Monday, May 05, 2014
Member Country details for listing OIE CWD 2013 against the criteria of Article 1.2.2., the Code Commission recommends consideration for listing
Friday, December 5, 2014
SPECIAL ALERT The OIE recommends strengthening animal disease surveillance worldwide
IN A NUT SHELL ; (Adopted by the International Committee of the OIE on 23 May 2006) 11. Information published by the OIE is derived from appropriate declarations made by the official Veterinary Services of Member Countries. The OIE is not responsible for inaccurate publication of country disease status based on inaccurate information or changes in epidemiological status or other significant events that were not promptly reported to the Central Bureau,
MONDAY, JANUARY 21, 2019
Bovine Spongiform Encephalopathy BSE TSE Prion Surveillance FDA USDA APHIS FSIS UPDATE 2019
USA MAD COW CASE 2018 FLORIDA
WEDNESDAY, SEPTEMBER 26, 2018
JAVMA In Short Update USDA announces detection of atypical BSE
MONDAY, NOVEMBER 30, 2020
***> REPORT OF THE MEETING OF THE OIE SCIENTIFIC COMMISSION FOR ANIMAL DISEASES Paris, 9–13 September 2019 BSE, TSE, PRION
see updated concerns with atypical BSE from feed and zoonosis...terry
WEDNESDAY, DECEMBER 23, 2020
BSE research project final report 2005 to 2008 SE1796 SID5
WEDNESDAY, DECEMBER 23, 2020
Idiopathic Brainstem Neuronal Chromatolysis IBNC BSE TSE Prion a Review 2020
Monday, November 30, 2020
Tunisia has become the second country after Algeria to detect a case of Camel Prion Disease CPD within a year
TUESDAY, NOVEMBER 17, 2020
The European Union summary report on surveillance for the presence of transmissible spongiform encephalopathies (TSE) in 2019 First published 17 November 2020
WEDNESDAY, OCTOBER 28, 2020
EFSA Annual report of the Scientific Network on BSE-TSE 2020 Singeltary Submission
WEDNESDAY, DECEMBER 2, 2020
EFSA Evaluation of public and animal health risks in case of a delayed post-mortem inspection in ungulates EFSA Panel on Biological Hazards (BIOHAZ) ADOPTED: 21 October 2020
i wonder if a 7 month delay on a suspect BSE case in Texas is too long, on a 48 hour turnaround, asking for a friend???
WEDNESDAY, JULY 31, 2019
The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
THURSDAY, SEPTEMBER 24, 2020
The emergence of classical BSE from atypical/ Nor98 scrapie
WEDNESDAY, APRIL 24, 2019
USDA Announces Atypical Bovine Spongiform Encephalopathy Detection Aug 29, 2018 A Review of Science 2019
WEDNESDAY, JULY 31, 2019
The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
THURSDAY, AUGUST 20, 2020
Why is USDA "only" BSE TSE Prion testing 25,000 samples a year?
TUESDAY, SEPTEMBER 22, 2020
APHIS USDA MORE SCRAPIE ATYPICAL Nor-98 Confirmed USA September 15 2020
SUNDAY, OCTOBER 4, 2020
Cattle Meat and Offal Imported from the United States of America, Canada and Ireland to Japan (Prions) Food Safety Commission of Japan
TUESDAY, SEPTEMBER 29, 2020
ISO's Updated 22442 Animal Tissue Standards — What Changed? TSE Prion!
MONDAY, NOVEMBER 23, 2020
Chronic Wasting Disease CWD TSE Prion Cervid State by State and Global Update November 2020
TUESDAY, DECEMBER 01, 2020
Sporadic Creutzfeldt Jakob Disease sCJD and Human TSE Prion Annual Report December 14, 2020
THURSDAY, FEBRUARY 15, 2018
Iatrogenic Creutzfeldt-Jakob disease with Amyloid-β pathology: an international study
http://creutzfeldt-jakob-disease.blogspot.com/2018/02/iatrogenic-creutzfeldt-jakob-disease.html
Iatrogenic Creutzfeldt-Jakob disease with Amyloid-β pathology: an international study
http://creutzfeldt-jakob-disease.blogspot.com/2018/02/iatrogenic-creutzfeldt-jakob-disease.html
WEDNESDAY, DECEMBER 04, 2019
Three Cases of Creutzfeldt-Jakob Disease with Visual Disturbances as Initial Manifestation
Friday, September 27, 2019
Prion disease and recommended procedures for flexible endoscope reprocessing – a review of policies worldwide and proposal for a simplified approach
THURSDAY, SEPTEMBER 26, 2019
Veterinary Biologics Guideline 3.32E: Guideline for minimising the risk of introducing transmissible spongiform encephalopathy prions and other infectious agents through veterinary biologics
SATURDAY, SEPTEMBER 21, 2019
National Variability in Prion Disease–Related Safety Policies for Neurologic Procedures
Wednesday, September 11, 2019
Is the re-use of sterilized implant abutments safe enough? (Implant abutment safety) iatrogenic TSE Prion
FRIDAY, SEPTEMBER 06, 2019
Disinfection of Multi-Use Ocular Equipment for Ophthalmological Procedures: A Review of Clinical Effectiveness, Cost-Effectiveness, and Guidelines
MONDAY, AUGUST 26, 2019
Creutzfeldt Jakob Disease CJD, TSE, Prion, Surveillance Update August 2019
SUNDAY, MARCH 10, 2019
National Prion Disease Pathology Surveillance Center Cases Examined¹ Updated Feb 1, 2019 Variably protease-sensitive prionopathy VPSPr
Wednesday, December 16, 2020
Expanding spectrum of prion diseases Prusiner et al
Terry S. Singeltary Sr.
Bacliff, Texas USA 77518
posted by Terry S. Singeltary Sr. | 11:34 AM
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