SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
Philippe Tixador, Laëtitia Herzog, Fabienne Reine, Emilie Jaumain, Jérôme Chapuis, Annick Le Dur, Hubert Laude*, Vincent Béringue*
INRA (Institut National de la Recherche Agronomique), UR892, Virologie Immunologie Moléculaires, Jouy-en-Josas, France
Abstract Top Prions are unconventional infectious agents thought to be primarily composed of PrPSc, a multimeric misfolded conformer of the ubiquitously expressed host-encoded prion protein (PrPC). They cause fatal neurodegenerative diseases in both animals and humans. The disease phenotype is not uniform within species, and stable, self-propagating variations in PrPSc conformation could encode this ‘strain’ diversity. However, much remains to be learned about the physical relationship between the infectious agent and PrPSc aggregation state, and how this varies according to the strain. We applied a sedimentation velocity technique to a panel of natural, biologically cloned strains obtained by propagation of classical and atypical sheep scrapie and BSE infectious sources in transgenic mice expressing ovine PrP. Detergent-solubilized, infected brain homogenates were used as starting material. Solubilization conditions were optimized to separate PrPSc aggregates from PrPC. The distribution of PrPSc and infectivity in the gradient was determined by immunoblotting and mouse bioassay, respectively. As a general feature, a major proteinase K-resistant PrPSc peak was observed in the middle part of the gradient. This population approximately corresponds to multimers of 12–30 PrP molecules, if constituted of PrP only. For two strains, infectivity peaked in a markedly different region of the gradient. This most infectious component sedimented very slowly, suggesting small size oligomers and/or low density PrPSc aggregates. Extending this study to hamster prions passaged in hamster PrP transgenic mice revealed that the highly infectious, slowly sedimenting particles could be a feature of strains able to induce a rapidly lethal disease. Our findings suggest that prion infectious particles are subjected to marked strain-dependent variations, which in turn could influence the strain biological phenotype, in particular the replication dynamics.
Author Summary Top Prions are unconventional transmissible agents causing fatal neurodegenerative diseases in human and animals. They are thought to be formed from polymers of abnormal conformations of the host-encoded prion protein (PrP), but little is known about the physical organization of the infectious particles and any relationship between packing order and infectivity. As an additional layer of complexity, different PrP conformational variants associated with distinct biological phenotypes, or ‘strains’, can propagate in the same host. We subjected PrP polymers from eight different ovine and hamster prion strains to sedimentation velocity centrifugation, which allows separation of macromolecular complexes according to their size, density or shape. We showed that, whereas the PrP sedimentation profiles share common features, the infectivity profiles exhibit striking differences amongst the strains. For four of them, the infectious component was predominantly associated with slowly sedimenting particles, suggestive of small size oligomers and/or low density PrP aggregates. Such particles appeared to be a feature of strains able to induce a rapidly lethal disease in the recipient host. Our findings suggest that prion infectious particles are subjected to marked strain-dependent variations, which in turn could influence the strain biological phenotype, in particular the replication dynamics.
Citation: Tixador P, Herzog L, Reine F, Jaumain E, Chapuis J, et al. (2010) The Physical Relationship between Infectivity and Prion Protein Aggregates Is Strain-Dependent. PLoS Pathog 6(4): e1000859. doi:10.1371/journal.ppat.1000859
Editor: Neil Mabbott, University of Edinburgh, United Kingdom
Received: July 6, 2009; Accepted: March 16, 2010; Published: April 15, 2010
Copyright: © 2010 Tixador et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was supported by a joint grant from INRA-Ile-de-France region and by a Fondation pour la Recherche Médicale fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: firstname.lastname@example.org (HL); email@example.com (VB)
Vet. Res. (2010) 41:48 Original article
Pathogenesis of natural goat scrapie: modulation by host PRNP genotype and effect of co-existent conditions
Lorenzo GONZÁLEZ, Stuart MARTIN, Stephen A. C. HAWKINS, Wilfred GOLDMANN, Martin JEFFREY and Sílvia SISÓ
Received: 13 January 2010 Accepted: 7 April 2010
After detection of a high prevalence of scrapie in a large dairy goat herd, 72 infected animals were examined by immunohistochemistry with prion protein (PrP) antibody Bar224 to study the pathogenesis of the infection. Tissues examined included the brain and thoracic spinal cord (TSC), a wide selection of lymphoreticular system (LRS) tissues, the distal ileum and its enteric nervous system (ENS), and other organs, including the mammary gland. The whole open reading frame of the PRNP gene was sequenced and antibodies to caprine arthritis-encephalitis virus (CAEV) infection were determined. Unexpectedly, accumulation of disease-associated PrP (PrPd) in the brain was more frequent in methionine carriers at codon 142 (24/32, 75.0%) than amongst isoleucine homozygotes (14/40, 35.0%). The latter, however, showed significantly greater amounts of brain PrPd than the former (average scores of 9.3 and 3.0, respectively). A significant proportion of the 38 goats that were positive in brain were negative in the ENS (44.7%) or in the TSC (39.5%). These results, together with the early and consistent involvement of the circumventricular organs and the hypothalamus, point towards a significant contribution of the haematogenous route in the process of neuroinvasion. Chronic enteritis was observed in 98 of the 200 goats examined, with no association with either scrapie infection or presence of PrPd in the gut. Lymphoproliferative interstitial mastitis was observed in 13/31 CAEV-positive and scrapie infected goats; PrPd in the mammary gland was detected in five of those 13 goats, suggesting a possible contribution of CAEV infection in scrapie transmission via milk.
Key words: scrapie / goat / prion neuroinvasion / transmissible spongiform encephalopathy / CAEV
The pathogenesis of scrapie in this heavily infected goat herd appeared to follow two different patterns depending on the polymorphisms at codon 142 of the PRNP gene. In goats of the wild-type genotype (isoleucine homozygotes), neuroinvasion did not occur until a high proportion of LRS tissues were positive, but once it happened, PrPd reached high levels in the brain and was often accompanied by the development of clinical disease. In other words, infection in goats of this genotype appeared to follow a conventional and progressive pattern. In contrast, methionine carriers showed an unpredictable pattern, so that accumulation of PrPd in the brain occurred regardless of the degree of lymphoid involvement, without reaching high values, and these goats rarely progressed to clinical disease. The age at which individual goats were exposed to infection cannot be known. However, even if the age were to be considered as an indicator of the duration of the infection this would not explain the discrepancies. Methionine carriers with PrPd in the brain were clearly younger than brain-positive isoleucione homozygotes but, while isoleucine homozygous goats without brain PrPd were younger than those positive in brain, the ages of methionine carriers with or without brain involvement was not significantly different. One possible explanation of the differences between the two groups would be a certain degree of interference of the methionine polymorphism on the ability of PrPd to accumulate in lymphoid tissues. Thus, it has been shown that sheep homozygous for the VRQ allele have a more extensive and earlier LRS involvement than ARR/VRQ sheep [1, 5, 7, 9, 11, 13, 26], and to a lesser extent than those of the ARQ/VRQ genotype [9, 11, 15, 26]1. The distinct pathogenesis of disease in codon 142 methionine carriers compared to isoleucine homozygotes did not appear to result from differences in the mechanisms of neuroinvasion. In this respect, several findings were common to most infected goats:
(1) a late and inconsistent involvement, as judged by PrPd accumulation, of the ENS and the TSC, which were negative even in a high proportion (44.7% and 39.5%, respectively) of the 38 goats that showed PrPd in the brain. This is in contrast with the findings reported from oral TSE experiments in sheep [27-29] and hamsters [2, 18]. A problem of low sensitivity of our approach could be argued, as only samples of distal ileum and thoracic segments of the spinal cord were examined. However, those areas of the gut and spinal cord have been repeatedly shown to be the more consistently positive than other gut or spinal segments in early stages of infection in sheep [28, 29].
(2) a highly consistent (68/72) and widespread involvement of LRS tissues, particularly amongst isoleucine homozygotes, which strongly suggests a widespread and persistent haematogenous dissemination of the scrapie agent. (3) an early involvement of the hypothalamus, which in some cases was the only structure of the neuroparenchyma affected in addition to the DMNV, in agreement with the reports for chronic wasting disease-infected deer .
(4) a consistent and early accumulation of PrPd in CVO, which in many cases preceded the involvement of neighbouring areas of the neuroparenchyma, and which is in agreement with recent findings in natural and experimental sheep TSE [22, 23].
Taken together, all these findings strongly suggest an important contribution of the blood in the process of neuroinvasion, which contrasts with the prevailing hypothesis of a neural neuroinvasion pathway, mainly derived from the oral experiments in sheep and rodents mentioned above. Whether this is particular to high prevalence natural infection, or to exposure to the agent by other routes than the oral, remains to be determined. The early and consistent involvement of the medial retropharyngeal lymph node and the palatine tonsil has been widely reported [1, 7, 16, 19, 26, 27], and it is believed to result from the early exposure of those tissues to infectivity following ingestion of the scrapie agent [1, 27, 29]. If that were the case, it would be difficult to explain the late and inconsistent involvement of the distal ileum Peyer’s patches observed in our study. We actually believe that those two LRS tissues are early and consistently involved due to a combination of pathogenetic mechanisms that include (i) exposure to the infectious agent after ingestion and possibly rumination, (ii) exposure to blood-borne infectious agent, and, distinctly, (iii) exposure to infectious agent which, coming from the blood and through the choroid plexus, would be present in the interstitial fluid of the brain and in the cerebrospinal fluid (CSF), even in the absence of detectable PrPd in the neuroparenchyma; the CSF in the subarachnoidal space would drain through the cribriform plate into an extracranial lymphatic network in the nasal submucosa and nasopharynx to reach the retropharyngeal lymph node . Some of the infectivity contained in the CSF would be excreted in the nasal cavity itself , and would represent another source of exposure for the pharyngeal (not examined in our study) and the palatine tonsils, which in turn also drain into the retropharyngeal lymph node. Although a link between enteritis and susceptibility to scrapie has been reported in an experimental murine model , such a relationship has not been found in our study, not even between inflammatory lesions and presence of PrPd in the gut. The most likely explanation would be that, in our study, scrapie infection and the development of enteric lesions were temporally unrelated, with scrapie infection occurring early in life and nonspecific enteritis being a late and progressive event.
Perhaps surprisingly, infections by CAE lentivirus and the scrapie agent, which in the 200 goats studied both showed a similar prevalence, also appeared to be unrelated. Transmission of CAEV through milk was demonstrated a long time ago and, more recently, transmission of sheep scrapie via milk has also been shown , and it is likely that it also occurs in goats. Moreover, detection of PrPd in the mammary gland of scrapie infected goats was only recorded in a proportion of those with CAEV-induced lymphoproliferative mastitis, in complete agreement with the findings reported by Lacroux et al.  in sheep. These authors, however, also found that milk from ewes both with and without PrPd in the mammary glands was infectious in rodent bioassay. This suggests that accumulation of PrPd in the mammary gland is unnecessary for excretion of the scrapie agent in the milk or for transmission of infection by this route. Assuming this to be true, the absence of a relationship between the two infections in the present study would be explained: goats could transmit via the milk either of the two infections, independently of their co-occurrence or otherwise, and regardless of any associated mastitis.
OLDER STUDIES BELOW ;
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.
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.
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.
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).
EMBO reports 4, 5, 530–533 (2003) doi:10.1038/sj.embor.embor827 AOP Published online: 11 April 2003
Widespread PrPSc accumulation in muscles of hamsters orally infected with scrapie
Achim Thomzig, Christine Kratzel, Gudrun Lenz, Dominique Krüger & Michael Beekes
Robert Koch-Institut, P26, Nordufer 20, D-13353 Berlin, Germany
To whom correspondence should be addressed Michael Beekes Tel: +49 30 4547 2396; Fax: +49 30 4547 2609; BeekesM@rki.de
Received 13 February 2003; Accepted 13 March 2003; Published online 11 April 2003.
Scrapie, bovine spongiform encephalopathy and chronic wasting disease are orally communicable, transmissible spongiform encephalopathies (TSEs). As zoonotic transmissions of TSE agents may pose a risk to human health, the identification of reservoirs for infectivity in animal tissues and their exclusion from human consumption has become a matter of great importance for consumer protection. In this study, a variety of muscles from hamsters that were orally challenged with scrapie was screened for the presence of a molecular marker for TSE infection, PrPSc (the pathological isoform of the prion protein PrP). Sensitive western blotting revealed consistent PrPSc accumulation in skeletal muscles from forelimb and hindlimb, head, back and shoulder, and in tongue. Previously, our animal model has provided substantial baseline information about the peripheral routing of infection in naturally occurring and orally acquired ruminant TSEs. Therefore, the findings described here highlight further the necessity to investigate thoroughly whether muscles of TSE-infected sheep, cattle, elk and deer contain infectious agents.
EMBO reports 4, 5, 530–533 (2003) doi:10.1038/sj.embor.embor827 AOP Published online: 11 April 2003
Nobel Lecture, December 13, 1976
ALSO, see in animal Scrapie;
New World monkeys : capuchin, spider, squirrel
Old World monkeys : cynomolgus macaque, rhesus
J Infect Dis. 1994 Apr;169(4):814-20.
Intracerebral transmission of scrapie to cattle.
Cutlip RC, Miller JM, Race RE, Jenny AL, Katz JB, Lehmkuhl HD, DeBey BM, Robinson MM.
USDA, Agriculture Research Service, National Animal Disease Center, Ames, IA 50010.
To determine if sheep scrapie agent(s) in the United States would induce a disease in cattle resembling bovine spongiform encephalopathy, 18 newborn calves were inoculated intracerebrally with a pooled suspension of brain from 9 sheep with scrapie. Half of the calves were euthanatized 1 year after inoculation. All calves kept longer than 1 year became severely lethargic and demonstrated clinical signs of motor neuron dysfunction that were manifest as progressive stiffness, posterior paresis, general weakness, and permanent recumbency. The incubation period was 14-18 months, and the clinical course was 1-5 months. The brain from each calf was examined for lesions and for protease-resistant prion protein. Lesions were subtle, but a disease-specific isoform of the prion protein was present in the brain of all calves. Neither signs nor lesions were characteristic of those for bovine spongiform encephalopathy.
PMID: 8133096 [PubMed - indexed for MEDLINE]
Second passage of a US scrapie agent in cattle
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R.C. Cutlip, J.M. Miller and H.D. Lehmkuhl
United States Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Ames, Iowa, USA
Received 10 September 1996; accepted 31 July 1997. Available online 25 May 2006.
Scrapie and bovine spongiform encephalopathy are similar chronic neurodegenerative diseases of sheep and cattle. An earlier study showed that, on first passage in cattle, a US scrapie agent caused an encephalopathy that was distinct from bovine spongiform encephalopathy (BSE). The present report describes a second passage in cattle, carried out because diseases caused by the spongiform encephalopathy agents often change in character with additional passages in abnormal hosts. For this work, young calves were inoculated intracerebrally with a pooled suspension of brain from cattle that had died of encephalopathy after experimental inoculation with brain from scrapie-affected sheep. The second passage disease was essentially identical with the first passage disease, as judged by clinical signs, histopathological findings and distribution of “prion protein scrapie” (PrPsc). This represents additional evidence to suggest that the US sheep scrapie agent tested is incapable of causing BSE in cattle.
Correspondence to: R. C. Cutlip, USDA, Agricultural Research Service, National Animal Disease Center, P.O. Box 70, 2300 Dayton Road, Ames, Iowa 50010, USA.
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. ........
Macaque Models of Human Infectious Disease
Macaques have served as models for more than 70 human infectious diseases of diverse etiologies, including a multitude of agents—bacteria, viruses, fungi, parasites, prions. The remarkable diversity of human infectious diseases that have been modeled in the macaque includes global, childhood, and tropical diseases as well as newly emergent, sexually transmitted, oncogenic, degenerative neurologic, potential bioterrorism, and miscellaneous other diseases. Historically, macaques played a major role in establishing the etiology of yellow fever, polio, and prion diseases. With rare exceptions (Chagas disease, bartonellosis), all of the infectious diseases in this review are of Old World origin. Perhaps most surprising is the large number of tropical (16), newly emergent (7), and bioterrorism diseases (9) that have been modeled in macaques. Many of these human diseases (e.g., AIDS, hepatitis E, bartonellosis) are a consequence of zoonotic infection. However, infectious agents of certain diseases, including measles and tuberculosis, can sometimes go both ways, and thus several human pathogens are threats to nonhuman primates including macaques. Through experimental studies in macaques, researchers have gained insight into pathogenic mechanisms and novel treatment and vaccine approaches for many human infectious diseases, most notably acquired immunodeficiency syndrome (AIDS), which is caused by infection with human immunodeficiency virus (HIV). Other infectious agents for which macaques have been a uniquely valuable resource for biomedical research, and particularly vaccinology, include influenza virus, paramyxoviruses, flaviviruses, arenaviruses, hepatitis E virus, papillomavirus, smallpox virus, Mycobacteria, Bacillus anthracis, Helicobacter pylori, Yersinia pestis, and Plasmodium species. This review summarizes the extensive past and present research on macaque models of human infectious disease.
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
28 Mar 01
Like lambs to the slaughter 31 March 2001 by Debora MacKenzie Magazine issue 2284. Subscribe and get 4 free issues. 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.
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.
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.
"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." 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.
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.
Then follow up with PNAS studies from which new scientist article written from;
Published online before print March 20, 2001 Proc. Natl. Acad. Sci. USA, 10.1073/pnas.041490898 Abstract of this Article Reprint (PDF) Version of this Article Similar articles found in: PNAS Online PubMed PubMed Citation Search Medline for articles by: Lasmézas, C. I. Deslys, J.-P. Alert me when: new articles cite this article Download to Citation Manager Neurobiology
Adaptation of the bovine spongiform encephalopathy agent to primates and comparison with Creutzfeldt- Jakob disease: Implications for human health
Corinne Ida Lasmézas*, [dagger] , Jean-Guy Fournier*, Virginie Nouvel*, Hermann Boe*, Domíníque Marcé*, François Lamoury*, Nicolas Kopp [Dagger ] , Jean-Jacques Hauw§, James Ironside¶, Moira Bruce  , Dominique Dormont*, and Jean-Philippe Deslys*
* Commissariat à l'Energie Atomique, Service de Neurovirologie, Direction des Sciences du Vivant/Département de Recherche Medicale, Centre de Recherches du Service de Santé des Armées 60-68, Avenue du Général Leclerc, BP 6, 92 265 Fontenay-aux-Roses Cedex, France; [Dagger ] Hôpital Neurologique Pierre Wertheimer, 59, Boulevard Pinel, 69003 Lyon, France; § Laboratoire de Neuropathologie, Hôpital de la Salpêtrière, 83, Boulevard de l'Hôpital, 75013 Paris, France; ¶ Creutzfeldt-Jakob Disease Surveillance Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; and  Institute for Animal Health, Neuropathogenesis Unit, West Mains Road, Edinburgh EH9 3JF, United Kingdom
Edited by D. Carleton Gajdusek, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France, and approved December 7, 2000 (received for review October 16, 2000)
Abstract Top Abstract Introduction Materials and Methods Results Discussion Conclusions References
There is substantial scientific evidence to support the notion that bovine spongiform encephalopathy (BSE) has contaminated human beings, causing variant Creutzfeldt-Jakob disease (vCJD). This disease has raised concerns about the possibility of an iatrogenic secondary transmission to humans, because the biological properties of the primate-adapted BSE agent are unknown. We show that (i) BSE can be transmitted from primate to primate by intravenous route in 25 months, and (ii) an iatrogenic transmission of vCJD to humans could be readily recognized pathologically, whether it occurs by the central or peripheral route. Strain typing in mice demonstrates that the BSE agent adapts to macaques in the same way as it does to humans and confirms that the BSE agent is responsible for vCJD not only in the United Kingdom but also in France. The agent responsible for French iatrogenic growth hormone-linked CJD taken as a control is very different from vCJD but is similar to that found in one case of sporadic CJD and one sheep scrapie isolate. These data will be key in identifying the origin of human cases of prion disease, including accidental vCJD transmission, and could provide bases for vCJD risk assessment.
Introduction Top Abstract Introduction Materials and Methods Results Discussion Conclusions References
The recognition of a variant of the human transmissible spongiform encephalopathy (TSE) Creutzfeldt-Jakob Disease (vCJD) in the U.K. in 1996 raised the major concern that it would correspond to human infection with the agent responsible for bovine spongiform encephalopathy (BSE; ref. 1). Transmission of BSE to macaques provided the first experimental evidence as it produced a disease close to vCJD in humans (2). Strain typing in inbred mice (consisting of measuring the incubation period and establishing lesion profiles corresponding to the strain-specific distribution of brain vacuolation) allows reliable identification of TSE strains (3). This method, together with biochemical methods, has revealed a single phenotype for the agents of BSE and the British cases of vCJD (4-6). Mice expressing only the bovine prion protein (PrP) were highly susceptible to vCJD and BSE, which induced the same disease (7). Thus, it is now well established that BSE has caused vCJD, probably by alimentary contamination. In this respect, the finding of abnormal PrP labeling in the gastrointestinal tract and lymphatic tissues of orally BSE-contaminated lemurs shows that the BSE agent can infect primates by the oral route (8). About 1 million contaminated cattle may have entered the human food chain, and the future number of vCJD cases could range from 63 to 136,000 depending on the incubation period of BSE in humans (9). Unlike sporadic CJD (sCJD) and iatrogenic CJD (iCJD) linked to the administration of contaminated growth hormone extracted from human hypophyses, in vCJD, the infectious agent seems to be widely distributed in lymphoid organs, as pathological PrP (PrPres) can be detected in tonsils, lymph nodes, spleen, and appendix even in the preclinical phase of the disease (10, 11). This raises a public health issue with regard to the risk of iatrogenic transmission of vCJD through surgical instruments, grafts, blood transfusion, or parenteral administration of biological products of human origin. However, this risk is difficult to assess, because it largely depends on factors such as the virulence of the BSE agent adapted to primates and the efficiency of secondary transmission to humans by a peripheral route such as the i.v. one. A further issue is whether vCJD accidentally acquired from humans would be recognized. The latter poses the question of a phenotypic variation of the BSE agent after successive transmissions in humans: does it retain its strain characteristics, and does it induce a pathology similar to that observed in the previous host? A 9-year history of transmission of BSE to primates and mice enables us today to clarify a number of these important points.
Although BSE has mainly affected the U.K., two definite cases and one probable case of vCJD have now been reported in France in people who have never resided in the U.K. (12, 13). We strain-typed the first of these cases to establish its origin. Strain typing in C57BL/6 mice of BSE, French, and British vCJD was compared with that of BSE passaged in nonhuman primates, thus allowing us to study the effect of serial passages in primates. Comparisons were also made with French cases of sCJD and iCJD and two strains of scrapie (one of French and one of U.S. origin). Our findings provide experimental demonstration that the same agent, namely that responsible for the cattle disease BSE, has caused vCJD both in France and in the U.K., in line with biochemical data and with the fact that, until 1996, about 10% of the beef consumed in France was imported from the U.K. We found that the BSE agent in nonhuman primates is similar to that causing vCJD in humans and tends to evolve rapidly toward a primate-adapted variant. Furthermore, we showed that the strain responsible for iCJD is closely related to that of one patient with sCJD, and, more unexpectedly, that these agents were similar to the French scrapie strain studied (but different from the U.S. scrapie strain). This finding requires a cautious interpretation for several reasons, not least because of the inevitably limited number of TSE strains that can be studied by such a cumbersome method as strain typing. Nonetheless, it also prompts reconsideration of the possibility that, in some instances, sheep and human TSEs can share a common origin.
The BSE Inquiry / Statement No 410 Dr Helen Grant Issued 13/05/1999 (not scheduled to give oral evidence) BSE INQUIRY STATEMENT OF DR HELEN GRANT MD FRCP
1. My credentials in the matters of BSE and CJD are: a. 1970-1982 Consultant Neuropathologist at the Middlesex Hospital. b. 1985-1989 Consultant Neuropathologist at the Charing Cross Hospital. c. I have carried out six autopsies on CJD victims and reported on a similar number of cerebral biopsies from CJD patients. 1. Through my interest in slow viruses (particularly with reference to multiple sclerosis) I was one of only a few people to be aware of both Scrapie and CJD in 1988. 2
. I have never had any formal links with the farming community, renderers, pet food manufacturers, etc. However, slaughterhouse workers began telephoning me as early as February 1989 after they learned through the media of my concern and knowledge about TSEs. Several of them rang me because they had had no instructions from the Health and Safety Executive about precautions to be taken to avoid infection from BSE carcases. (I have kept some of the correspondence with these workers together with my list of precautions to be taken in abattoirs).
3. I asked the slaughterhouses workers in detail to explain the routine slaughtering practices and was astonished to learn that sheep’s brains were generally left inside the skull whereas cattle brains were routinely removed to be added to our "meat products" – meat pies, pates, tinned items and stock cubes. I therefore feared that this almost indestructible infective agent was being swallowed by all beef eaters in the UK in large doses which would inevitably infect genetically susceptible people.
4. I was horrified because I suddenly realised why Government assurances about BSE – namely "we have lived with scrapie for two-and-a-half centuries and it has not done us any harm so we won’t have any trouble with BSE" – were based on a false premise which was that cattle brains and sheep’s brains were dealt with in the same way in the abattoirs which they obviously were not. Since sheep’s brains were seldom removed from the skulls (which is why cattle caught scrapie in the first place) we humans have never been seriously exposed over the centuries to the scrapie agent. Simple economics is the reason: sheep’s brains are too small to make the intricate process of their removal worthwhile.
5. I appeared on the BBC nine o’clock television news on February 27, 1989 (the day the Southwood Report was published) in my capacity as consultant neuropathologist at Charing Cross hospital. I was asked among other things to comment on the possible human hazard of BSE and I warned that I thought there was a risk because cattle brains were going into our food chain. I added: "Who knows? Some of us may be incubating it already." Some of us were.
6. I was called to give evidence to the House of Commons Agriculture Select Committee on 13 June 1990 (IBD 1 Tab 7 p 42). On re-reading it, I see no reason to change anything in my evidence except the numbers of animals mentioned. The Government of the day was hardly disposed to ask my advice about BSE on a regular basis given my critical attitude since early 1989. But the then Labour Opposition, understandably anxious for information, turned to me frequently. Opposition Members included David Clark MP, Ron Davies MP and Ian McCartney MP. It was my technical information which helped Ron Davies MP to make his effective speech about BSE in the House of Commons on 17 May 1989 (M 7 Tab 7). Shortly afterwards, the Minister for Agriculture, John MacGregor, announced that legislation would be brought in to ban all cattle brains from human food (YB 89/6.13/5.1-5.2). The long summer recess delayed this legislation and the "specified offals" ban was finally enacted on 9 November 1989 (L2 Tab 4) (9 February 1990 in Scotland) (L10 Tab 9). Of course this was more than a year (15 months) after cattle had been protected in the same way.
7. Apart from my involvement with CJD I have of course been interested in that worldwide scourge, multiple sclerosis (MS). This led me to ponder the question of "slow virus infection – now labelled "prion infection" (an inaccurate title. In my opinion prion is a short title for an organism which causes Transmissible Spongiform Encephalopathy (TSE) such as scrapie, CJD, BSE, Kuru and others. Prion diseases has therefore become widely used instead of the cumbersome alternative (YB 94/4.25/10.1)) – which is one of the aetiological factors involved in MS. Scrapie, the ovine TSE, was then and still is by far the most extensively researched slow virus infection. I therefore read up all the papers on the subject as they appeared during the 1950s, ‘60s and ‘70s and was therefore immediately aware of the human hazard posed by the BSE catastrophe. Vets generally did not know about CJD (why should they?) and neuropathologists were mostly ignorant of scrapie. I happened to know about both in those early days due to my interest in "slow viruses".
8. I was in receipt of no extra funds beyond those provided by the NHS and the University of London to run my laboratories and pay my salary as a senior lecturer/honorary Consultant and I suffered no constraints over my publications, lectures to my students, or statements to the media. However, I became increasingly aware after 1988 that questioning official dogma about BSE brought difficulties to one’s career. I was myself about to retire from the Charing Cross Hospital, where I worked as a Consultant Neuropathologist, but I observed with horror that the good reputations of dissenting scientists in the field, not least Dr Stephen Dealler and especially Dr Harash Narang were systematically undermined.
9. My primary function has been to teach medical under-graduates and post-graduates about diseases of the brain and nervous system and, of course, to fulfil my clinical functions as a consultant neuropathologist at two London teaching hospitals. This, of course, meant that I conducted both biopsies and autopsies including those on patients with CJD: it was not primarily to publish scientific articles. My scientific publications include only one case which I think in retrospect may be CJD before that was known to be an infection with this agent. ("Post Traumatic Dementia": Helen C Grant, Behrman et al. Archiv für Psyciatre und Zeitschrift für die ges. Neurologie. 1965; 207: 128) More importantly I have carried out several biopsies and autopsies on CJD patients. My duties also included the initiation and supervision of research projects. When my trainees and PhD students published their resulting scientific papers I took the view that the work was theirs, they should get the credit (not I) and therefore I made it a matter of principle not to add my name as co-author.
10. I corresponded frequently from February 1989 onwards with Government ministers including John MacGregor, Donald Thomson, Gillian Shepherd and Angela Browning. But I received only short and reassuring replies containing what I believed to be inaccurate information. Because official bodies treated my early warnings with hostility, I soon learned that the only way to convey my concerns was to contribute relevant letters to the broadsheet newspapers and to speak to responsible members of the press, the broadcasting services and informed members of Opposition parties.
11. Since February 1989 I have answered innumerable letters from members of the public understandably anxious – if not panicky – about the effect on their diets of the outbreak. They came/come from a cross-section of the community: parents ("is the milk safe?"), restaurateurs, doctors, butchers, journalists, Education Committees. Since I retired finally in March 1989 I have had the time to answer them all eventually.
12. The BSE/CJD problem is quite incomprehensible without knowledge of the facts set out in Annex 1. The infective agent has unique and sinister properties.
Issued on behalf of the witness by: The BSE Inquiry Press Office 6th Floor Hercules House Hercules Road London SE1 7DU Fax: 0171 803 0893 Website: http://www.bse.org.uk Email: firstname.lastname@example.org
NOR-98 ATYPICAL SCRAPIE USA 4 CASES DETECTED JANUARY 2010
Scrapie Flock Certification Program
As of January 31, 2010, there were 1,701 flocks participating in the Scrapie Flock Certification Program (SFCP). Of these flocks, 1,094 were complete monitored flocks, 551 were certified, 51 were export monitored, and 5 were selective monitored flocks (Figures 1 and la). Six flocks were enrolled or certified during January (Figure 2). SFCP open statuses by fiscal year from FY 1997 to FY 2010 are depicted in Chart 1.
Infected and Source Flocks
As of January 31, 2010, there were 11 scrapie infected and source flocks with open statuses (Figure 3). There were no flocks designated as infected or source in January. In FY 2010, two new infected flocks and two new source flocks were reported (Figure 4); eight flocks completed a clean-up plan and were released (Figure 5). The ratio of infected and source flocks released to newly identified infected and source flocks for FY 2010 = 2 : 1. New infected and source statuses from FY 1997 to FY 2010 are depicted in Chart 2.
Positive Scrapie Cases
As of January 31, 2010, 24 positive cases in sheep or goats were reported by the National Veterinary Services Laboratories (NVSL); 14 were field cases and 10 were Regulatory Scrapie Slaughter Surveillance (RSSS) cases collected between October 1,2009 and January 31,2010 and confirmed by February 19,2010 (Figure 6). Three RSSS cases and one field case were diagnosed as Nor98-like scrapie. Field cases are positive animals tested as part of a disease investigation including potentially exposed, exposed, and suspect animals. Twenty one cases of scrapie in goats have been confirmed by NVSL since implementation of the regulatory changes in FY 2002 (Figure 7). The most recent positive goat case was confirmed rectal biopsy positive in November 2009 and originated in the same herd in Michigan as the positive goat cases that were found in FY 2008. The positive goat has been held in quarantine for research by USDA's Agricultural Research Service since 2008.
Regulatory Scrapie Slaughter Surveillance (RSSS)
RSSS started April 1, 2003. It is a targeted slaughter surveillance program which is designed to identify infected flocks. Samples have been collected from 246,453 animals since April 1, 2003. There have been 431 NVSL confirmed positive animals since the beginning ofRSSS. As of January 31, 2010, 15,184 samples have been collected in FY 2010. Seven samples collected in FY 2010 have tested positive for classical scrapie"; the face colors of the positive sheep were 5 black-face and 2 mottled-face. Three samples (2 mottled-face and 1 white-face sheep) tested positive for Nor98-like scrapie. The percent of samples that have tested positive for each face color from FY 2003 through 2010 is depicted in Chart 3. Cumulative regional sample collection numbers are shown in Chart 4 and are based upon the state in which the animal was tagged. The number ofRSSS animals collected for FY 2010 by month and by region where collected is shown in Chart 5. A monthly comparison ofRSSS collections by fiscal year is displayed in Chart 6. A retrospective 6 month rolling average of the percent positive, black-faced sheep sampled at RSSS collections sites is shown in Chart 7.
*RSSS positives are reported based on collection date and may have been confirmed after January 31,2010.
Animals Sampled for Scrapie Testing
As of January 31, 2010,15,693 animals have been sampled for scrapie testing: 15,184 RSSS samples, 428 regulatory field cases, and 81 live-animal biopsies (Chart 8).
This report is based on information and test results available at the time of report generation. Numbers are subject to change due to later reporting of test results and updates in the database.
Unusual event if you consider the officials hypothisis that Nor-98 atypical scrapie is a spontaneous event. seems there was a great deal of spontaneous mutations for the this time period. ...TSS
Atypical Nor-98 states in this report for January 2010 include ; Maine, Pennsylvania, Ohio, and Oregon
kind regards, terry
Monday, December 14, 2009
Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types
hmmm, this is getting interesting now...
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.
see full text ;
Monday, December 14, 2009
Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types
Epidemiology of Scrapie in the United States 1977
1: Cent Eur J Public Health 2003 Mar;11(1):19-22
Analysis of unusual accumulation of Creutzfeldt-Jakob disease cases in Orava and Liptov regions (northern Slovak focus) 1983-2000.
Mad'ar R, Maslenova D, Ranostajova K, Straka S, Baska T.
Institute of Epidemiology, Jessenius Faculty of Medicine, Comenius University, Sklabinska 26, Martin, 037 53 Slovakia. MADAR@jfmed.uniba.sk
While familial cases of Creutzfeldt-Jakob disease are extremely rare all over the world, 3 familial clusters were observed between 1983-2000 in a relatively small area situated in the North of Slovakia. Prevalence of CJD in this area exceeded the overall prevalence in Slovakia more than 8 times. The majority of CJD patients admitted consuming sheep brain. Most patients lived in small secluded villages with rather common familial intermarriage. CJD affected both sexes equally. All patients were prior to the disease mentally normal individuals. Shortly after the onset of CJD their mental status deteriorated remarkably with an average survival rate of 3.6 months.
1: Eur J Epidemiol 1991 Sep;7(5):520-3
"Clusters" of CJD in Slovakia: the first laboratory evidence of scrapie.
Mitrova E, Huncaga S, Hocman G, Nyitrayova O, Tatara M.
Institute of Preventive and Clinical Medicine, Bratislava.
Epidemic-like occurrence of Creutzfeldt-Jakob disease was observed in 1987 in Slovakia (Orava). Search for the cause of CJD focus indicated a coincidence of genetic and environmental risks in clustering patients. Since Spongiform Encephalopathies might be transmitted orally, (Bovine Spongiform Encephalopathy), the possibility of zoonotic source of CJD cases in Orava was also considered. A deficient knowledge about the occurrence of scrapie in Slovakia stimulated an examination of sheep with signs of CNS disorders in two flocks of Valasky breed in Orava. In one flock, neurohistopathological examination revealed in sheep brains lesions characteristic for scrapie. Frozen brain tissue of these animals were used for the detection of scrapie associated fibrils. They were found in 2 animals from the same flock. This is the first laboratory confirmation of scrapie in Czecho-Slovakia. The possible epidemiological and economical implications are emphasized.
Mutation of the prion protein in Libyan Jews with Creutzfeldt-Jakob disease Article Abstract:
Creutzfeldt-Jakob disease (CJD) is a neurodegenerative disease of a class referred to as the spongiform encephalopathies. The disease can be transmitted experimentally and has also been transmitted accidentally. The causative agent in these transmissions is unlike any well characterized infectious agent and is referred to by many as a prion. Creutzfeldt-Jakob disease may occur in families, but is usually sporadic. The incidence of Creutzfeldt-Jakob disease is about one or two cases per million people. However, among Jews from Libya, the incidence is 100 times higher. Many possible explanations have been put forward to account for this unusually high incidence, but none has sustained any scrutiny. One of the more popular notions was that the eating of sheep brains, a popular delicacy in the region, infected people with scrapie, a prion disease of sheep similar to CJD. However, the eating of sheep brain is popular throughout the Mediterranean, and cannot explain the specificity of the increased incidence to Libyan Jews. Mediterranean sheep, if anything, have a lower rate of scrapie than other areas of Europe and North America. A study was undertaken to determine if the increased incidence of CJD among these people might be accounted for by genetic factors. The prion protein genes were analyzed in 11 Libyan Jews with Creutzfeldt-Jakob disease. Investigation of one patient revealed that a mutation had occurred in the 200th codon of the gene, that is, the 200th set of three DNA bases. The net result of this change would be to substitute a lysine for glutamine in the resulting protein. After this mutation was identified, it was confirmed in the other 10 Libyan patients. It is interesting to note that the mutation was not present in a Moroccan Jew with CJD. The results suggest that the increased incidence of Creutzfeldt-Jakob disease in this population is the result of a gene carried by this group. In eight of the present cases, a family history of CJD could be confirmed. Although not all families were cooperative in providing information of the ancestral heritage, all the families for which such information was available could be traced to Djerba, which is an island off the coast of Tunisia. (Consumer Summary produced by Reliance Medical Information, Inc.)
author: Scarlato, Guglielmo, Prusiner, Stanley B., Hsiao, Karen, Meiner, Zeev, Kahana, Esther, Cass, Carin, Kahana, Irit, Avrahami, Dana, Abramsky, Oded, Gabizon, Ruth Publisher: Massachusetts Medical Society Publication Name: The New England Journal of Medicine Subject: Health ISSN: 0028-4793 Year: 1991
The EMBO Journal, Vol. 19, No. 17 pp. 4425-4430, 2000 Â© European Molecular Biology Organization
Evidence of a molecular barrier limiting susceptibility of humans, cattle and sheep to chronic wasting disease
G.J. Raymond1, A. Bossers2, L.D. Raymond1, K.I. O?Rourke3, L.E. McHolland4, P.K. Bryant III4, M.W. Miller5, E.S. Williams6, M. Smits2 and B. Caughey1,7
1NIAID/NIH Rocky Mountain Laboratories, Hamilton, MT 59840, 3USDA/ARS/ADRU, Pullman, WA 99164-7030, 4USDA/ARS/ABADRL, Laramie, WY 82071, 5Colorado Division of Wildlife, Wildlife Research Center, Fort Collins, CO 80526-2097, 6Department of Veterinary Sciences, University of Wyoming, Laramie, WY 82070, USA and 2ID-Lelystad, Institute for Animal Science and Health, Lelystad, The Netherlands 7Corresponding author e-mail: email@example.com Received June 7, 2000; revised July 3, 2000; accepted July 5, 2000.
Clearly, it is premature to draw firm conclusions about CWD passing naturally into humans, cattle and sheep, but the present results suggest that CWD transmissions to humans would be as limited by PrP incompatibility as transmissions of BSE or sheep scrapie to humans. Although there is no evidence that sheep scrapie has affected humans, it is likely that BSE has caused variant CJD in 74 people (definite and probable variant CJD cases to date according to the UK CJD Surveillance Unit). Given the presumably large number of people exposed to BSE infectivity, the susceptibility of humans may still be very low compared with cattle, which would be consistent with the relatively inefficient conversion of human PrP-sen by PrPBSE. Nonetheless, since humans have apparently been infected by BSE, it would seem prudent to take reasonable measures to limit exposure of humans (as well as sheep and cattle) to CWD infectivity as has been recommended for other animal TSEs.
BSE: TIME TO TAKE H.B. PARRY SERIOUSLY
If the scrapie agent is generated from ovine DNA and thence causes disedase in other species, then perhaps, bearing in mind the possible role of scrpaie in CJD of humans (Davinpour et al, 1985), scrapie and not BSE should be the notifiable disease. ...
Sheep consumption: a possible source of spongiform encephalopathy in humans.
Davanipour Z, Alter M, Sobel E, Callahan M.
Abstract 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.
PMID: 3915057 [PubMed - indexed for MEDLINE]
Tuesday, April 28, 2009
Nor98-like Scrapie in the United States of America
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute,
Norway Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
NOR98 SHOWS MOLECULAR FEATURES REMINISCENT OF GSS
R. Nonno1, E. Esposito1, G. Vaccari1, E. Bandino2, M. Conte1, B. Chiappini1, S. Marcon1, M. Di Bari1, S.L. Benestad3, U. Agrimi1 1 Istituto Superiore di Sanità, Department of Food Safety and Veterinary Public Health, Rome, Italy (firstname.lastname@example.org); 2 Istituto Zooprofilattico della Sardegna, Sassari, Italy; 3 National Veterinary Institute, Department of Pathology, Oslo, Norway
Molecular variants of PrPSc are being increasingly investigated in sheep scrapie and are generally referred to as "atypical" scrapie, as opposed to "classical scrapie". Among the atypical group, Nor98 seems to be the best identified. We studied the molecular properties of Italian and Norwegian Nor98 samples by WB analysis of brain homogenates, either untreated, digested with different concentrations of proteinase K, or subjected to enzymatic deglycosylation. The identity of PrP fragments was inferred by means of antibodies spanning the full PrP sequence. We found that undigested brain homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11), truncated at both the C-terminus and the N-terminus, and not N-glycosylated. After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11. Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at the highest concentrations, similarly to PrP27-30 associated with classical scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment of 17 kDa with the same properties of PrP11, that was tentatively identified as a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in 2% sodium laurylsorcosine and is mainly produced from detergentsoluble, full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a sample with molecular and pathological properties consistent with Nor98 showed plaque-like deposits of PrPSc in the thalamus when the brain was analysed by PrPSc immunohistochemistry. Taken together, our results show that the distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids ~ 90-155. This fragment is produced by successive N-terminal and C-terminal cleavages from a full-length and largely detergent-soluble PrPSc, is produced in vivo and is extremely resistant to PK digestion.
*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.
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.
Monday, December 1, 2008
When Atypical Scrapie cross species barriers
Andreoletti O., Herva M. H., Cassard H., Espinosa J. C., Lacroux C., Simon S., Padilla D., Benestad S. L., Lantier F., Schelcher F., Grassi J., Torres, J. M., UMR INRA ENVT 1225, Ecole Nationale Veterinaire de Toulouse.France; ICISA-INlA, Madrid, Spain; CEA, IBiTec-5, DSV, CEA/Saclay, Gif sur Yvette cedex, France; National Veterinary Institute, Postboks 750 Sentrum, 0106 Oslo, Norway, INRA IASP, Centre INRA de Tours, 3738O Nouzilly, France.
Atypical scrapie is a TSE occurring in small ruminants and harbouring peculiar clinical, epidemiological and biochemical properties. Currently this form of disease is identified in a large number of countries. In this study we report the transmission of an atypical scrapie isolate through different species barriers as modeled by transgenic mice (Tg) expressing different species PRP sequence.
The donor isolate was collected in 1995 in a French commercial sheep flock. inoculation into AHQ/AHQ sheep induced a disease which had all neuro-pathological and biochemical characteristics of atypical scrapie. Transmitted into Transgenic mice expressing either ovine or PrPc, the isolate retained all the described characteristics of atypical scrapie.
Surprisingly the TSE agent characteristics were dramatically different v/hen passaged into Tg bovine mice. The recovered TSE agent had biological and biochemical characteristics similar to those of atypical BSE L in the same mouse model. Moreover, whereas no other TSE agent than BSE were shown to transmit into Tg porcine mice, atypical scrapie was able to develop into this model, albeit with low attack rate on first passage.
Furthermore, after adaptation in the porcine mouse model this prion showed similar biological and biochemical characteristics than BSE adapted to this porcine mouse model. Altogether these data indicate.
(i) the unsuspected potential abilities of atypical scrapie to cross species barriers
(ii) the possible capacity of this agent to acquire new characteristics when crossing species barrier
These findings raise some interrogation on the concept of TSE strain and on the origin of the diversity of the TSE agents and could have consequences on field TSE control measures.
"Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. [Many of the neurological diseases can be transmitted by intracerebral inoculation, which causes this moderator to approach intracerebral studies as a tool for study, but not necessarily as a direct indication of transmissibility of natural diseases. - Mod.TG]
"The 1st successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.
"Results -------- "This study demonstrates that atypical scrapie has distinct clinical, pathological, and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.
"Conclusions ------------ Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage."
Lastly, this moderator wishes to thank Terry Singletary for some of his behind the scenes work of providing citations and references for this posting. - Mod.TG]
The HealthMap/ProMED-mail interactive map of Australia is available at
Sunday, March 28, 2010
SPAIN BSE, Nor-98 atypical scrapie, SPORADIC CJD HIGH INCIDENT RATE >2 PER MILLION
NOR-98 ATYPICAL SCRAPIE 5 cases documented in USA in 5 different states USA 2007
Tuesday, June 3, 2008 SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PA
Wednesday, July 1, 2009
Nor98 scrapie identified in the United States J Vet Diagn Invest 21:454-463 (2009)
Wednesday, March 3, 2010
NOR-98 ATYPICAL SCRAPIE USA 4 CASES DETECTED JANUARY 2010
Sunday, March 28, 2010
Nor-98 atypical Scrapie, atypical BSE, spontaneous TSE, trade policy, sound science ?
URGENT DATA ON ATYPICAL BSE RISK FACTORS TO HUMANS AND ANIMALS OIE REFUSE TO ACKNOWLEDGE $
position: Post Doctoral Fellow Atypical BSE in Cattle
Closing date: December 24, 2009
Anticipated start date: January/February 2010
Employer: Canadian and OIE Reference Laboratories for BSE CFIA Lethbridge Laboratory, Lethbridge/Alberta
To date the OIE/WAHO assumes that the human and animal health standards set out in the BSE chapter for classical BSE (C-Type) applies to all forms of BSE which include the H-type and L-type atypical forms. This assumption is scientifically not completely justified and accumulating evidence suggests that this may in fact not be the case. Molecular characterization and the spatial distribution pattern of histopathologic lesions and immunohistochemistry (IHC) signals are used to identify and characterize atypical BSE. Both the L-type and H-type atypical cases display significant differences in the conformation and spatial accumulation of the disease associated prion protein (PrPSc) in brains of afflicted cattle. Transmission studies in bovine transgenic and wild type mouse models support that the atypical BSE types might be unique strains because they have different incubation times and lesion profiles when compared to C-type BSE. When L-type BSE was inoculated into ovine transgenic mice and Syrian hamster the resulting molecular fingerprint had changed, either in the first or a subsequent passage, from L-type into C-type BSE. In addition, non-human primates are specifically susceptible for atypical BSE as demonstrated by an approximately 50% shortened incubation time for L-type BSE as compared to C-type. Considering the current scientific information available, it cannot be assumed that these different BSE types pose the same human health risks as C-type BSE or that these risks are mitigated by the same protective measures.
Sunday, April 4, 2010
USDA AND OIE OUT OF TOUCH WITH RISK FACTOR ON ATYPICAL TSE
Wednesday, March 31, 2010
Atypical BSE in Cattle
Monday, April 5, 2010
Update on Feed Enforcement Activities to Limit the Spread of BSE April 5, 2010
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518