Full Scientific Reports
Experimental oral transmission of United States origin scrapie to neonatal sheep
Amir N. Hamir1, Robert A. Kunkle, Justin J. Greenlee and Juergen A. Richt Correspondence: 1Corresponding Author: Amir N. Hamir, National Animal Disease Center, ARS, USDA, 2300 Dayton Avenue, PO Box 70, Ames, IA 50010. mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000111/!x-usc:mailto:firstname.lastname@example.org
Scrapie, a transmissible spongiform encephalopathy (TSE), is a naturally occurring fatal neurodegenerative disease of sheep and goats. The current study documents incubation periods, pathologic findings, and distribution of abnormal prion proteins (PrPSc) by immunohistochemistry and Western blot in tissues of genetically susceptible and resistant neonatal lambs inoculated with pooled brain homogenates from 13 U.S. origin scrapie-affected ewes. Nine Suffolk lambs with genotypes AA/RR/QQ (n = 5) and AA/RR/QR (n = 4) at codons 136, 154, and 171, respectively) were orally inoculated, within 12 hr of birth, with 1 ml of a 10% (w/v) brain homogenate prepared from scrapie-affected sheep brains. Inoculated animals were euthanized when advanced clinical signs of scrapie were observed. All QQ sheep developed clinical signs of scrapie, with a mean survival time of 24 months. Spongiform lesions in the brains and PrPSc deposits in the central nervous system and lymphoid tissues were present in these sheep. None of the QR sheep succumbed to the disease. A previous study that used a larger volume (30 ml of 10% brain suspension) of the same inoculum in 4-month-old Suffolk lambs of susceptible genotype documented longer survival periods (average 32 months), and only 5 of 9 inoculated sheep developed scrapie. Findings of this study suggest that orally exposed neonatal lambs of a susceptible (QQ) genotype exhibit a higher attack rate and shorter incubation period than older (4-month-old) lambs exposed to a larger dose (30x) of the same inoculum.
Key Words: Immunohistochemistry • neonatal sheep • scrapie • spongiform encephalopathy • Western blothttp://jvdi.org/cgi/content/abstract/21/1/64?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=prion&searchid=1&FIRSTINDEX=0&volume=21&issue=1&resourcetype=HWCIT
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.http://www.neuroprion.org/resources/pdf_docs/conferences/prion2008/abstract-book-prion2008.pdf
INFECTED AND SOURCE FLOCKS
There were 20 scrapie infected and source flocks with open statuses (Figure 3) as of April, 30, 2008. Twenty eight new infected and source flocks have been designated in FY 2008 (Figure 4); three source flocks were reported in April. ...snip
POSITIVE SCRAPIE CASES
As of April 30, 2008, 122 new scrapie cases have been confirmed and reported by the National Veterinary Services Laboratories (NVSL) in FY 2008 (Figure 6). Of these, 103 were field cases and 19* were Regulatory Scrapie Slaughter Surveillance (RSSS) cases (collected in FY 2008 and reported by May 20, 2008). Positive cases reported for April 2008 are depicted in Figure 7. Eighteen cases of scrapie in goats have been confirmed by NVSL since implementation of the regulatory changes in FY 2002 (Figure 8). The most recent positive goat case was confirmed in February 2008 and originated from the same herd in Michigan as the other FY 2008 goat cases. ...snip
CAPRINE SCRAPIE PREVALENCE STUDY (CSPS)
However, four positive goats have been identified this fiscal year through field investigations. One was a clinical suspect submitted for testing and the other three originated from the birth herd of the clinical case.
ANIMALS SAMPLED FOR SCRAPIE TESTING
As of April 30, 2008, 26,703 animals have been sampled for scrapie testing: 23,378 RSSS, 1,517 goats for the CSPS study, 1,466 regulatory field cases, 270 regulatory third eyelid biopsies, and 72 regulatory rectal biopsies (chart 8).
TESTING OF LYMPHOID TISSUE OBTAINED BY RECTAL BIOPSY WAS APPROVED BY USDA AS AN OFFICIAL LIVE-ANIMAL TEST ON JANUARY 11, 2008. ...
PLEASE NOTE, (FIGURE 6), Scrapie Confirmed Cases in FY 2008 MAP, PA 3, 1**, Two cases-state of ID UNKNOWN, 1 case Nor98-like**http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.ppshttp://scrapie-usa.blogspot.com/
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.http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
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.
Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved September 12, 2005 (received for review March 21, 2005)http://www.pnas.org/cgi/content/abstract/0502296102v1
NOR-98 ATYPICAL SCRAPIE 5 cases documented in USA in 5 different states USA 007http://nor-98.blogspot.com/2008/04/seac-spongiform-encephalopathy-advisory.html
Tuesday, June 3, 2008 SCRAPIE USA UPDATE JUNE 2008 NOR-98 REPORTED PAhttp://nor-98.blogspot.com/2008/06/scrapie-usa-update-june-2008-nor-98.htmlhttp://nor-98.blogspot.com/
Monday, December 1, 2008 When Atypical Scrapie cross species barriershttp://nor-98.blogspot.com/2008/12/when-atypical-scrapie-cross-species.html
Monday, September 1, 2008 RE-FOIA OF DECLARATION OF EXTRAORDINARY EMERGENCY BECAUSE OF AN ATYPICAL T.S.E. (PRION DISEASE) OF FOREIGN ORIGIN IN THE UNITED STATES [No. 00-072-1] September 1, 2008
Greetings again BSE-L members,
I had a pleasant surprise this past Saturday. I got an unexpected package from O.I.G. on my old F.O.I.A. request, of the final test results of the infamous mad sheep of mad river valley. IF you all remember, back on Thu, 24 Apr 2008 15:00:20 -0500 I wrote ;
With great disgust, I must report, that after years and years of wrangling over the infamous mad sheep of mad river valley, I have failed in getting an official answer via FOIA on the outcome of the TSE testing of those imported Belgium sheep. The USA Government refuses to tell the public, exactly what the testing outcome was, and in doing so, shows just how corrupt this administration has been. and the excuse given in their answer to my final appeal, which they have now officially denied, was bizarre to say the least ;
"I am denying your FOIA appeal. This is the final agency decision. You may seek judicial review of this decision in the United States district court for the judicial district in which you reside or have your principal place of business or in the District of Columbia, pursuant to 5 U.S.C. & 552(a)(4)(B)."
FOIA OF DECLARATION OF EXTRAORDINARY EMERGENCY BECAUSE OF AN ATYPICAL T.S.E. (PRION DISEASE) OF FOREIGN ORIGIN IN THE UNITED STATES [Docket No. 00-072-1] ...snip...end...TSS
NOW, out of the wild blue, AFTER them telling me they denied my FOIA appeal for the final time, any further action would have to be judicial review in the United States district court, I get 25+ pages, a lot of redacted names, etc, but this is the first time they sent me anything about this in the 6 years of waiting for my FOIA request. IT will take me a long time to get this online due to the fact you cannot hardly read it, very poor quality and eligibility of text. BUT, the just of it is, somebody (REDACTED) screwed those tests up. I will work to get all the data online next week or so, but it is odd how much they were concerned for human and animal health from an atypical scrapie of foreign origin back then, but yet when we document it here in the USA, you don't hear a word about it. it's a completely different story.
IN SHORT ;
August 15, 2000
OIG case # NY-3399-56 REDACTED, VT
''Enclosed is OIG's notification that they have scheduled an investigation of the following individual. REDACTED is alleged to have provided possibly inaccurate test results involving diseased sheep. However, because the results were determined to be inconclusive, no actual violation was actually committed.''
[only bush et al could have interpreted it that way. don't all criminals wish this is the way the system worked. ...tss]
JULY, 28, 2000
Case Opening Memorandum
An investigation regarding the subject identified below will be conduced and a report submitted at the conclusion of the investigation. If you have or should later receive additional information concerning this matter, please forward it to this office.
If you believe that administrative action should be taken before all criminal and other legal matters are completed, please coordinate that action with this office in order not to jeopardize the ongoing investigation.
The fact that this subject is under investigation should not be discussed with anyone who does not have a need to know and all inquiries on the investigation should be referred to the office of Inspector General.
FOR OFFICIAL USE ONLY FEBRUARY 7, 2002
SUBJECT OIG CASE NY-3399-56 REDACTED VT HEALTH/SANITATION VIOLATION
TO: William Buisch, Regional Director Eastern Region, VS Raleigh, NC
Enclosed is the official investigation report on REDACTED. If you will recall, REDACTED is alleged to have provided possible inaccurate test results involving diseased sheep.
OIG is closing their file upon issuance of the Report of Investigation (copy enclosed). We are, therefore, also closing our case file.
Resource Management Systems and Evaluation Staff
REDACTED IES, Riverdale, MD (w/cy of incoming)
APHIS:RMSES: REDACTED 2/7/02 "NY-3399-56-REDACTED Closure''
NOW, the question is, who screwed those test up, and was it done on purpose, just to cover someone's ass for letting those sheep in here in the first place ???
WHICH tests were compromised, one of them, all of them, and, can we trust the outcome of any of these test under the circumstances here ???
"It is significant that four of the sheep which first tested positive on REDACTED Western blot tests, thereby providing the type of confirmation the plaintiffs argue is lacking on the current record."
UNDER what circumstances were these test compromised ???
MY basic, simple question, was not answered in layman term, i.e. exactly what strain of TSE did those sheep have ???
IS this the best we can do ???
>>>"REDACTED is alleged to have provided possibly inaccurate test results involving diseased sheep. However, because the results were determined to be inconclusive, no actual violation was actually committed.''<<<http://www.usda.gov/oig/webdocs/sarc070619.pdf
FOR IMMEDIATE RELEASE Statement May 4, 2004 Media Inquiries: 301-827-6242 Consumer Inquiries: 888-INFO-FDA
Statement on Texas Cow With Central Nervous System Symptoms
On Friday, April 30 th , the Food and Drug Administration learned that a cow with central nervous system symptoms had been killed and shipped to a processor for rendering into animal protein for use in animal feed. FDA, which is responsible for the safety of animal feed, immediately began an investigation. On Friday and throughout the weekend, FDA investigators inspected the slaughterhouse, the rendering facility, the farm where the animal came from, and the processor that initially received the cow from the slaughterhouse. FDA's investigation showed that the animal in question had already been rendered into "meat and bone meal" (a type of protein animal feed).
Over the weekend FDA was able to track down all the implicated material. That material is being held by the firm, which is cooperating fully with FDA. Cattle with central nervous system symptoms are of particular interest because cattle with bovine spongiform encephalopathy or BSE, also known as "mad cow disease," can exhibit such symptoms. In this case, there is no way now to test for BSE. But even if the cow had BSE, FDA's animal feed rule would prohibit the feeding of its rendered protein to other ruminant animals (e.g., cows, goats, sheep, bison).http://www.fda.gov/bbs/topics/news/2004/new01061.html
BESIDES the Texas mad cow that sat on the shelf for 7+ months before the Honorable Phyllis Fong of the OIG finally did the end around Johanns et al and finally had Weybridge bring that negative cow back from the dead to finally being a confirmed mad cow (hint, hint, getting MRR implemented first), was this simply another bumbling of BSE protocol, or just same old same old; Jim Rogers (202) 690-4755 USDA Press Office (202) 720-4623 Statement by Chief Veterinary Medical Officer John Clifford Animal and Plant Health Inspection Service Regarding Non-Definitive BSE Test Results July 27, 2005
Our laboratory ran the IHC test on the sample and received non-definitive results that suggest the need for further testing. As we have previously experienced, it is possible for an IHC test to yield differing results depending on the “slice” of tissue that is tested. Therefore, scientists at our laboratory and at Weybridge will run the IHC test on additional “slices” of tissue from this animal to determine whether or not it was infected with BSE. We will announce results as soon as they are compiled, which we expect to occur by next week. I would note that the sample was taken in April, at which time the protocols allowed for a preservative to be used (protocols changed in June 2005). The sample was not submitted to us until last week, because the veterinarian set aside the sample after preserving it and simply forgot to send it in. On that point, I would like to emphasize that while that time lag is not optimal, it has no implications in terms of the risk to human health. The carcass of this animal was destroyed, therefore there is absolutely no risk to human or animal health from this animal.
please see full text ;http://bse-atypical.blogspot.com/2008/06/mad-cows-and-computer-models-us.html
USDA: In 9,200 cases only one type of test could be used
WASHINGTON (AP)--The U.S. Department of Agriculture acknowledged Aug. 17 that its testing options for bovine spongiform encephalopathy were limited in 9,200 cases despite its effort to expand surveillance throughout the U.S. herd.
In those cases, only one type of test was used--one that failed to detect the disease in an infected Texas cow.
The department posted the information on its website because of an inquiry from The Associated Press.
Conducted over the past 14 months, the tests have not been included in the department's running tally of BSE tests since last summer. That total reached 439,126 on Aug. 17. "There's no secret program," the department's chief veterinarian, John Clifford, said in an interview. "There has been no hiding, I can assure you of that."
Officials intended to report the tests later in an annual report, Clifford said.
These 9,200 cases were different because brain tissue samples were preserved with formalin, which makes them suitable for only one type of test--immunohistochemistry, or IHC. In the Texas case, officials had declared the cow free of disease in November after an IHC test came back negative. The department's inspector general ordered an additional kind of test, which confirmed the animal was infected.
Veterinarians in remote locations have used the preservative on tissue to keep it from degrading on its way to the department's laboratory in Ames, Iowa. Officials this year asked veterinarians to stop using preservative and send fresh or chilled samples within 48 hours.
The department recently investigated a possible case of BSE that turned up in a preserved sample. Further testing ruled out the disease two weeks ago.
Scientists used two additional tests--rapid screening and Western blot--to help detect BSE in the country's second confirmed case, in a Texas cow in June. They used IHC and Western blot to confirm the first case, in a Washington state cow in December 2003.
"The IHC test is still an excellent test," Clifford said. "These are not simple tests, either." Clifford pointed out that scientists reran the IHC several times and got conflicting results. That happened, too, with the Western blot test. Both tests are accepted by international animal health officials.
WELL, someone did call me from Bio-Rad about this, however it was not Susan Berg. but i had to just about take a blood oath not to reveal there name. IN fact they did not want me to even mention this, but i feel it is much much to important. I have omitted any I.D. of this person, but thought I must document this ;
Bio-Rad, TSS phone conversation 12/28/04..........
snip... FULL TEXT ;http://foiamadsheepmadrivervalley.blogspot.com/2008/09/re-foia-of-declaration-of-extraordinary.html
FOIA MAD SHEEP MAD RIVER VALLEYhttp://foiamadsheepmadrivervalley.blogspot.com/
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. ........http://www.bseinquiry.gov.uk/files/yb/1994/02/07002001.pdf
TRANSMISSION TO CHIMPANZEE'S
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 filed isolates subsequently strain typed in mice be 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 chimpanzees 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 man's susceptibility. In the meantime no doubt the negativity would be used defensively. IT WOULD HOWEVER BE COUNTERPRODUCTIVE IF THE EXPERIMENT BECAME POSITIVE. We may learn more about public reactions following next Monday's meeting.
23 September 1990
CVO (+ Mr Wells' comments)
Dr T W A Little
Dr B J Shreeve
AGRICULTURAL RESEARCH COUNCIL REPORT OF THE ADVISORY COMMITTE ON SCRAPIE
Office Note CHAIRMAN: PROFESSOR PETER WILDY
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.
3.57 The experiment which might have determined whether BSE and scrapie were caused by the same agent (ie, the feeding of natural scrapie to cattle) was never undertaken in the UK. It was, however, performed in the USA in 1979, when it was shown that cattle inoculated with the scrapie agent endemic in the flock of Suffolk sheep at the United States Department of Agriculture in Mission, Texas, developed a TSE quite unlike BSE.339 The findings of the initial transmission, though not of the clinical or neurohistological examination, were communicated in October 1988 to Dr Watson, Director of the CVL, following a visit by Dr Wrathall, one of the project leaders in the Pathology Department of the CVL, to the United States Department of Agriculture.340 The results were not published at this point, since the attempted transmission to mice from the experimental cow brain had been inconclusive. The results of the clinical and histological differences between scrapie-affected sheep and cattle were published in 1995. Similar studies in which cattle were inoculated intracerebrally with scrapie inocula derived from a number of scrapie-affected sheep of different breeds and from different States, were carried out at the US National Animal Disease Centre.341 The results, published in 1994, showed that this source of scrapie agent, though pathogenic for cattle,
*** did not produce the same clinical signs of brain lesions characteristic of BSE. ***
3.58 There are several possible reasons why the experiment was not performed in the UK. It had been recommended by Sir Richard Southwood (Chairman of the Working Party on Bovine Spongiform Encephalopathy) in his letter to the Permanent Secretary of MAFF, Mr (now Sir) Derek Andrews, on 21 June 1988,342 though it was not specifically recommended in the Working Party Report or indeed in the Tyrrell Committee Report (details of the Southwood Working Party and the Tyrell Committee can be found in vol. 4: The Southwood Working Party, 1988–89 and vol. 11: Scientists after Southwood respectively). The direct inoculation of scrapie into calves was given low priority, because of its high cost and because it was known that it had already taken place in the USA.343 It was also felt that the results of such an experiment would be hard to interpret. While a negative result 337 Fraser, H., Bruce, M., Chree, A., McConnell, I. and Wells, G. (1992) Transmission of Bovine Spongiform Encephalopathy and Scrapie to Mice, Journal of General Virology, 73, 1891–7; Bruce, M., Chree, A., McConnell, I., Foster, J., Pearson, G. and Fraser, H. (1994) Transmission of Bovine Spongiform Encephalopathy and Scrapie to Mice: Strain Variation and the Species Barrier, Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences, 343, 405–11 338 Bruce, M., Will, R., Ironside, J., McConell, I., Drummond, D., Suttie, A., McCordie, L., Chree, A., Hope, J., Birkett, C., Cousens, S., Fraser, H. and Bostock, C. (1997) Transmissions to Mice Indicate that ‘New Variant’ CJD is Caused by the BSE Agent, Nature, 389, 498–501 339 Clark, W., Hourrigan, J. and Hadlow, W. (1995) Encephalopathy in Cattle Experimentally Infected with the Scrapie Agent, American Journal of Veterinary Research, 56, 606–12 340 YB88/10.00/1.1 341 Cutlip, R., Miller, J., Race, R., Jenny, A., Katz, J., Lehmkuhl, H., Debey, B. and Robinson, M. (1994) Intracerebral Transmission of Scrapie to Cattle, Journal of Infectious Diseases, 169, 814–20 342 YB88/6.21/1.2 343 YB88/11.17/2.4 SCIENCE 84 would be informative, a positive result would need to demonstrate that when scrapie was transmitted to cattle, the disease which developed in cattle was the same as BSE.344 Given the large number of strains of scrapie and the possibility that BSE was one of them, it would be necessary to transmit every scrapie strain to cattle separately, to test the hypothesis properly. Such an experiment would be expensive. Secondly, as measures to control the epidemic took hold, the need for the experiment from the policy viewpoint was not considered so urgent. It was felt that the results would be mainly of academic interest.345 3.59 Nevertheless, from the first demonstration of transmissibility of BSE in 1988, the possibility of differences in the transmission properties of BSE and scrapie was clear. Scrapie was transmissible to hamsters, but by 1988 attempts to transmit BSE to hamsters had failed. Subsequent findings increased that possibility.http://www.bseinquiry.gov.uk/pdf/volume2/chapter3.pdf
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.
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. BSE was not reported in the USA.
CWD occurred principally in two locations, this one at Sybille and in a similar faccility at Fort Collins, Colorado, some 120 miles southwest. It was estimated that in total probably 60-70 cases of CWD have occurred.
It was difficult to gain a clear account of incidence and temporal sequence of events (-this presumably is data awaiting publication - see below) but during the period 1981-1984, 10-15 cases occurred at the Sybille facility.
The moribidity amongst mule deer in the facilities ie. those of the natural potentially exposed group has been about 90% with 100% mortality.
Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf
Sunday, December 28, 2008
MAD COW DISEASE USA DECEMBER 28, 2008 an 8 year review of a failed and flawed policyhttp://bse-atypical.blogspot.com/2008/12/mad-cow-disease-usa-december-28-2008-8.html
Terry S. Singeltary Sr.
P.O. Box 42
Bacliff, Texas USA 77518
Labels: Immunohistochemistry • neonatal sheep • scrapie • spongiform encephalopathy • Western blot