Wednesday, September 17, 2014

Cost benefit analysis of the development and use of ante-mortem tests for transmissible spongiform encephalopathies

Cost benefit analysis of the development and use of ante-mortem tests for transmissible spongiform encephalopathiesProject Code: M03067

 

 14/02/2014

 

The FSA’s Strategic Plan for 2005–2010 committed the Agency to promote and aid the development of a sensitive, rapid live test for TSEs by 2010. This study carried out a cost-benefit analysis of the implementation of such tests.

 

The review of the state of the science has not identified any ante-mortem test for BSE that is currently ready for use or for approval. Taking into account the likely timescale for approval and modification of policy to enable the introduction of live animal tests, and the attitude of commercial companies to the challenges and risks involved, there appears to be little scope for their introduction in the foreseeable future.

 

This study has demonstrated that although desirable, it is not necessary to have a live animal test that works at all stages of incubation. It has been shown that improving sensitivity from 3 to 12 months before clinical onset has a real impact, and potential benefits. This could help to define the minimum specification for a live animal test, i.e. 100% specificity and 95% sensitivity within 12 months of clinical onset, at least for the protection of the food chain. Applying an ante-mortem test to all cattle slaughtered increases the costs significantly with no additional benefit in terms of TSE exposure, resulting in a cost effectiveness value of 0.4.

 


 

July 2010

 

Cost Effectiveness Study of the use of Ante-mortem TSE Tests

 

Food Standards Agency

 

Page i

 

DNV

 

Final Report v 4 M03067 21-07-10

 

Reference to part of this report which may lead to misinterpretation is not permissible

 

Executive Summary

 

This report presents the results of a study carried out by Det Norske Veritas (DNV) for the Food Standards Agency (FSA) to assess the cost effectiveness of the introduction of ante-mortem tests for Transmissible Spongiform Encephalopathies (TSEs) in the United Kingdom. The study has focused on the implementation of ante-mortem tests for BSE in cattle at the current stage of the BSE epidemic, when prevalence levels are low.

 

The study has included a review of the state of the science relating to the development and approval of ante-mortem TSE tests. This included a review of the literature intended to inform the development of possible test scenarios, and consultation with scientists and companies known to be involved in the research and development of ante-mortem tests. This review led to the definition of a set of possible scenarios for the introduction of live animal tests for TSEs. These were discussed and reviewed at an Expert Workshop held in September 2009 and involving experts from a range of stakeholders, including regulators, the meat industry, veterinarians and people involved in test development. The outcome of the Expert Workshop was that the cost effectiveness assessment should focus on the introduction of a live test on healthy cattle carried out on farm before being sent for slaughter and involve either all cattle sent for slaughter or just adult cattle (over 48 months old at slaughter) as currently tested post-mortem. Testing of healthy cattle pre-slaughter at abattoirs was also considered, but it was felt that this would only be possible if the test provided an almost instant result and that this was unlikely to be achieved.

 

The cost effectiveness of the introduction of an ante-mortem TSE test has been evaluated by considering the range of costs that would be associated with implementing ante-mortem testing for the agreed scenarios compared with the benefit, measured as the estimated change in exposure to TSE infectivity resulting from the use of the test. The potential for TSE infectivity to enter the human food supply has been evaluated using a model based on the DNV SRM Controls Model that was developed for the FSA and used to estimate the impact of alternative supervision strategies for SRM Controls. The DNV SRM Controls Model has been previously reviewed by the Spongiform Encephalopathy Advisory Committee (SEAC) and the results for assessing alternative options for supervision of SRM controls accepted.

 

Study Conclusions:

 

1. The review of the state of the science has not identified any ante-mortem test for BSE that is currently ready for use or for approval. Taking into account the likely timescale for approval and modification of policy to enable the introduction of live animal tests, and the attitude of commercial companies to the challenges and risks involved, there appears to be little scope for their introduction in the foreseeable future.

 

2. Test specificity is likely to be critical to the acceptance of live animal testing, by both industry and consumers. The prospect of substantial numbers of false positive results that perpetuate fear of undetected or unconfirmed infection may undermine any attempts to introduce such tests.

 

3. Assuming that an ante-mortem test would be able to detect infectivity for a wider range of the incubation period than is currently possible with the present post-mortem tests, at least for the last 12 months of the incubation period, then it is estimated that the median exposure would reduce from 3 bovine oral ID50 units with the present post-mortem testing programme (range 0.2 to 52) to 0.02 bovine oral ID50 units (range <0 .01="" 0.5="" 100="" 48="" a="" and="" animals="" ante-mortem="" applied="" div="" food="" for="" months="" older="" only="" sensitivity.="" slaughtered="" test="" than="" the="" to="" with="">
 

July 2010

 

Cost Effectiveness Study of the use of Ante-mortem TSE Tests

 

Food Standards Agency

 

Page ii

 

DNV

 

Final Report v 4 M03067 21-07-10

 

Reference to part of this report which may lead to misinterpretation is not permissible

 

4. The estimated exposure for an ante-mortem test with 95% sensitivity is a median value of 0.3 (range 0.02 to 6) bovine oral ID50 units; this is still significantly less than the exposure with the present post-mortem test.

 

5. Testing the prime beef cattle in addition to those over 48 months of age at slaughter, does not result in any significant further reduction in exposure to TSE infectivity, as the untested prime beef animals contribute only 3% of the total exposure.

 

6. The cost of applying an ante-mortem test to over 48 month old cattle on farm prior to being sent for slaughter is estimated to be only slightly greater than that for the present post-mortem test; £6.9 million per year as opposed to £6.2 million. The higher costs of sampling on farm with the need for cattle handling and for a veterinarian to take the sample is partly off set by a reduction in MHS supervision costs.

 

7. The higher cost for ante-mortem testing is balanced by the additional reduction in TSE exposure, so that the cost effectiveness of the ante-mortem test applied to over 48 month animals is estimated to be 2.1 bovine oral ID50 units per £million spent as opposed to 0.9 for the post-mortem test. However, the significance of this increase in cost effectiveness needs to take into account the fact that the TSE exposure to the UK population from beef consumption is already at a very low level.

 

8. Applying an ante-mortem test to all cattle slaughtered increases the costs significantly with no additional benefit in terms of TSE exposure, resulting in a cost effectiveness value of 0.4.

 

9. With no data on the actual cost of an ante-mortem test it has been assumed that this would be the same as for the post-mortem test. If this cost were higher it would reduce the cost effectiveness of the ante-mortem test; however it has been shown that the ante-mortem test remains more cost effective provided that the cost of the test is no more than 3 times that of the post-mortem test.

 

10. The sampling costs for the ante-mortem test could be reduced by using a technical officer rather than a veterinarian to take the sample. It has been shown that this would increase the cost effectiveness only slightly from 2.1 to 2.4 Bovine oral ID50 units per million GBP.

 

11. If the introduction of a reliable ante-mortem test were to enable a change in the EU requirements for removing and disposing of SRM, this could result in a substantial cost saving, estimated to be £16 million. This estimated cost saving is greater than the cost of the test. However, discussions with the EU indicate that rapid ante-mortem tests will never be accepted as alternatives to the removal of SRM.

 

12. This study has demonstrated that although desirable, it is not necessary to have a live animal test that works at all stages of incubation. It has been shown that improving sensitivity from 3 to 12 months before clinical onset has a real impact, and potential benefits. This could help to define the minimum specification for a live animal test, i.e., 100% specificity and 95% sensitivity within 12 months of clinical onset, at least for the protection of the food chain.

 

13. This study has focussed on the application of TSE testing in cattle. Whilst there are grounds for greater optimism for the development of ante-mortem tests in small ruminants, there is currently little evidence of a test approach that could be used in a similar way as that investigated for bovines in this study.

 

July 2010

 

Cost Effectiveness Study of the use of Ante-mortem TSE Tests

 

Food Standards Agency

 

SNIP...

 

2.2.5 Lymphoreticular biopsies

 

Despite the extensive body of evidence that lymphoreticular biopsies can be used for the screening of sheep exposed to scrapie (Espenes et al, 2006; Gonzalez et al, 2005, 2006, 2008, a, b; O’Rourke et al, 1998, 2000, 2002), or farmed and wild cervids infected with CWD (Keane et al, 2009; Spraker et al, 2009; Wild et al, 2002), there is no published evidence of any attempt to use lymphoid biopsies as a matrix for testing in bovines. Nevertheless, in the context of BSE, where testing of cattle must provide equivalent protection to the removal of SRM, none of the evidence from sheep and cervids suggests that satisfactory levels of sensitivity and specificity would have been achieved, even if bovine LRS had been found to be PrPres–positive.

 

2.3 Consultations

 

2.3.1 Consultation with test-developers

 

A questionnaire was sent via the Veterinary Laboratories Agency (VLA) to 23 companies or institutes that had requested materials from the VLA TSE archive in the past for the purposes of test development or validation, with particular emphasis on live tests. Another company known to be involved in both research and continued test development, but which had not received materials from the VLA, was approached directly. In addition, some scientists funded by the FSA and Defra in recent years under the banner of “diagnostics” were sent an equivalent questionnaire, either via their funding body (FSA), or directly in the case of staff at the VLA and the Roslin Biocentre. Four detailed questionnaires, and one background note, were received from scientists contacted via the FSA or directly. Two commercial companies, currently involved in marketing post-mortem tests for BSE and scrapie, responded with a completed questionnaire. Three

 

July 2010 Cost Effectiveness Study of the use of Ante-mortem TSE Tests Food Standards Agency Page 6 DNV Final Report v 4 M03067 21-07-10 Reference to part of this report which may lead to misinterpretation is not permissible

 

others confirmed their withdrawal from this field of development. Many others are known, on the basis of historical personal contact, to have re-directed their activities.

 

The following represents a summary of relevant detail provided in the six completed questionnaires. All six confirmed a desire to develop a test for use on blood, while two also expressed an interest in testing milk, and one also targeted CSF. Four approaches involved the detection of PrPSc, one used proteomics while the fifth targeted up-regulation of ERAF. The latter approach has since been abandoned because of the considerable variability in results from healthy large animals and humans which confounded discrimination between infected and healthy individuals.

 

Only three of the six responses indicated a desire or scope to test bovines; these three did not include the commercial companies. All six were interested in testing sheep both as an end in itself and as a model for test development. Only three groups had an immediate interest in developing a test for humans, while two felt there was scope for testing cervids (but subsequently abandoned by one).

 

It was suggested that a test for BSE in bovines could possibly be available within two to three years, but only if it was firstly demonstrated that test methodology that worked on sheep could actually detect PrPSc in bovine blood. The key challenge to test development was the continuing lack of understanding of pathogenesis.

 

The commercial companies confirmed that the absence of national and international policy for the future use of live tests was a factor that hindered test development. Because of the inability to define a future market, the costs of developing a test could not be compared with potential future income in order to offer confidence that there would be returns on investment.

 

In summary, none of the respondents indicated that a live test for BSE was likely to be available in the immediate future. Nevertheless, it is known that at least three commercial companies that were not amongst the respondents are still interested in marketing a test for CJD in humans, and can legitimately be considered to have a real interest in the testing of bovines. This is no longer a priority for them however, and will probably not be progressed if they fail to gain approval for the testing of human blood.

 

2.4 Consultation with the European Commission/EFSA

 

The European Commission was consulted with respect to its medium term expectations, in the context of the TSE RoadMap (EC, 2005), which acknowledges a need to de-regulate with time, and its open-call for test developers to submit tests for approval. The benchmark of 100% sensitivity and specificity established in the first evaluation of post-mortem tests conducted in 1999 remains a serious challenge to the approval of any live animal test. The absence of a definitive gold standard to confirm the status of preclinical animals irrespective of stage of incubation remains a major obstacle to evaluating the true performance of ante-mortem tests. At present the EFSA guidelines for the evaluation of a live animal test are limited to a preliminary evaluation of sensitivity and specificity (EFSA, 2007b). How a formal evaluation of suitability for use on a wider scale will be conducted is partly dependent on the analyte to be measured, and whether appropriate test materials are available to enable such studies to be carried out. It is not however expected that rapid ante-mortem tests will ever be accepted as alternatives to the removal of SRM. It is also clear that tests will be expected to have diagnostic sensitivity not less than 100% (95% confidence limit not less than 98.5%)(EFSA 2007a).

 

July 2010

 

Cost Effectiveness Study of the use of Ante-mortem TSE Tests Food Standards Agency Page 7 DNV Final Report v 4 M03067 21-07-10 Reference to part of this report which may lead to misinterpretation is not permissible

 

The Commission cannot offer a forward plan for the integration of live animal testing within the EU programme of statutory testing.

 

Although it has no plans to extend the call for test evaluations any further than 2012, and cannot confirm its policy regarding the likely context in which such a test might be introduced, much will inevitably depend on timing, the prevalence of infection and costs of introduction at the time. If live animal tests are not available until such time as the EU testing programme has been reduced significantly, because of the low prevalence of BSE, the issue of equivalence with SRM removal will be less of an issue, and may enable a flexible and positive approach to application for herd certification if such a demand exists.

 

2.5 Consultation with the OIE

 

The OIE confirmed that although it could accommodate live animal tests within guidelines for international trade, and for diagnosis of BSE, it has not yet drafted protocols for the evaluation of live-animal tests, and has no plans to draft any at present. Consequently it has no proposals for the context in which it may accept the introduction of live tests, and will no doubt await evidence of successful development before taking this issue forward.

 

2.6 Small Ruminants

 

With respect to small ruminants it is clear that while there are grounds for greater optimism than with bovines, significant challenges remain. There is a need for clarity on the extent to which genotype confers resistance to infection with specific strains (absolute or relative) when exposed by natural routes. Within specific breed/genotype/scrapie strain combinations there is a need to confirm the performance of putative tests. Finally there will be difficulties in confirming the effectiveness of a test with respect to all strain/genotype combinations present within a national flock. Where there may only be a limited number of strains involved, there may be scope for live tests to be used in specific scenarios, such as flock/herd certification or culling of exposed animals. At the moment there is little evidence of a test approach that can be used for scenarios equivalent to those discussed for cattle in this study.

 

2.7 Conclusion

 

The review of the state of the science identified no test for BSE that is currently ready for use or for approval. Taking into account the likely timescale for approval and modification of policy to enable the introduction of live animal tests, and the attitude of commercial companies to the challenges and risks involved, there appears to be little scope for their use in the foreseeable future.

 

An issue that has also been highlighted by the review and the stakeholder consultation is that test specificity is likely to be critical to the acceptance of live animal testing, by both industry and consumers. While test sensitivity is already recognised as important when perception of risk is so important in determining the climate of national and international acceptability, the prospect of substantial numbers of false positive results that perpetuate fear of undetected or unconfirmed infection may undermine any attempts to introduce such tests. Realistically there is a need for not one but two tests that are capable of detecting infected animals at any stage of incubation, one for screening and one for confirmation. Failure to confirm the results of a primary positive result will critically undermine confidence in any screening programme. It will also be important to ensure that approaches to diagnosis in the screening and confirmatory tests are sufficiently different to ensure that they are not compromised for the same reason, in order to discriminate between false and true positives.

 

July 2010

 

Cost Effectiveness Study of the use of Ante-mortem TSE Tests

 

Food Standards Agency

 

 SNIP...

 

PLEASE SEE FULL TEXT ;

 


 

BOTTOM LINE $$$

 

IF YOU TEST, YOU FIND, and the more you test, the more you will find.

 

HUMANS ARE EXPENDABLE WITH A SLOW, LONG INCUBATING, 100% FATAL DISEASE, ONCE CLINICAL DISEASE...tss

 

 

Transmissible Spongiform Encephalopathy TSE Prion Disease North America 2014

 

Transmissible Spongiform Encephalopathy TSE Prion Disease have now been discovered in a wide verity of species across North America. typical C-BSE, atypical L-type BASE BSE, atypical H-type BSE, atypical H-G BSE, of the bovine, typical and atypical Scrapie strains, in sheep and goats, with atypical Nor-98 Scrapie spreading coast to coast in about 5 years. Chronic Wasting Disease CWD in cervid is slowly spreading without any stopping it in Canada and the USA and now has mutated into many different strains. Transmissible Mink Encephalopathy TME outbreaks. These Transmissible Spongiform Encephalopathy TSE Prion Disease have been silently mutating and spreading in different species in North America for decades.

 

The USDA, FDA, et al have assured us of a robust Triple BSE TSE prion Firewall, of which we now know without a doubt, that it was nothing but ink on paper. Since the 1997 mad cow feed ban in the USA, literally tons and tons of banned mad cow feed has been put out into commerce, never to return, as late as December of 2013, serious, serious breaches in the FDA mad cow feed ban have been documented. The 2004 enhanced BSE surveillance program was so flawed, that one of the top TSE prion Scientist for the CDC, Dr. Paul Brown stated ; Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive.

 

see ;

 


 

The BSE surveillance and testing have also been proven to be flawed, and the GAO and OIG have both raised serious question as to just how flawed it has been (see GAO and OIG reports). North America has more documented TSE prion disease, in different documented species (excluding the Zoo BSE animals in the EU), then any other place on the Globe. This does not include the very likelihood that TSE prion disease in the domestic feline and canine have been exposed to high doses of the TSE prion disease vid pet food. To date, it’s still legal to include deer from cwd zone into pet food or deer food. Specified Risk Material i.e. SRM bans still being breach, as recently as just last month.

 

nvCJD or what they now call vCJD, another case documented in Texas last month, with very little information being released to the public on about this case? with still the same line of thought from federal officials, ‘it can’t happen here’, so another vCJD blamed on travel of a foreign animal disease from another country, while ignoring all the BSE TSE Prion risk factors we have here in the USA and Canada, and the time that this victim and others, do spend in the USA, and exposed to these risk factors, apparently do not count in any way with regard to risk factor. a flawed process of risk assessment.

 

sporadic CJD, along with new TSE prion disease in humans, of which the young are dying, of which long duration of illness from onset of symptoms to death have been documented, only to have a new name added to the pot of prion disease i.e. sporadic GSS, sporadic FFI, and or VPSPR. I only ponder how a familial type disease could be sporadic with no genetic link to any family member? when the USA is the only documented Country in the world to have documented two different cases of atypical H-type BSE, with one case being called atypical H-G BSE with the G meaning Genetic, with new science now showing that indeed atypical H-type BSE is very possible transmitted to cattle via oral transmission (Prion2014). sporadic CJD and VPSPR have been rising in Canada, USA, and the UK, with the same old excuse, better surveillance. You can only use that excuse for so many years, for so many decades, until one must conclude that CJD TSE prion cases are rising. a 48% incease in CJD in Canada is not just a blip or a reason of better surveillance, it is a mathematical rise in numbers. More and more we are seeing more humans exposed in various circumstance in the Hospital, Medical, Surgical arenas to the TSE Prion disease, and at the same time in North America, more and more humans are becoming exposed to the TSE prion disease via consumption of the TSE prion via deer and elk, cattle, sheep and goats, and for those that are exposed via or consumption, go on to further expose many others via the iatrogenic modes of transmission of the TSE prion disease i.e. friendly fire. I pondered this mode of transmission via the victims of sporadic FFI, sporadic GSS, could this be a iatrogenic event from someone sub-clinical with sFFI or sGSS ? what if?

 

Two decades have passed since Dr. Ironside first confirmed his first ten nvCJD victims in 1995. Ten years later, 2005, we had Dr. Gambetti and his first ten i.e. VPSPR in younger victims. now we know that indeed VPSPR is transmissible. yet all these TSE prion disease and victims in the USA and Canada are being pawned off as a spontaneous event, yet science has shown, the spontaneous theory has never been proven in any natural case of TSE prion disease, and scientist have warned, that they have now linked some sporadic CJD cases to atypical BSE, to atypical Scrapie, and to CWD, yet we don’t here about this in the public domain. We must make all human and animal TSE prion disease reportable in every age group, in ever state and internationally, we must have a serious re-evaluation and testing of the USA cattle herds, and we must ban interstate movement of all cervids. Any voluntary effort to do any of this will fail. Folks, we have let the industry run science far too long with regards to the TSE prion disease. While the industry and their lobbyist continues to funnel junk science to our decision policy makers, Rome burns. ...end

 

REFERENCES

 

Sunday, June 29, 2014

 

*** Transmissible Spongiform Encephalopathy TSE Prion Disease North America 2014

 


 

Wednesday, August 27, 2014

 

Highly sensitive detection of small ruminant BSE within TSE mixes by serial Protein Misfolding Cyclic Amplification

 


 

Tuesday, September 2, 2014

 

*** COOL UPDATE September 2, 2014

 


 

Tuesday, August 12, 2014

 

*** MAD COW USDA TSE PRION COVER UP or JUST IGNORANCE, for the record AUGUST 2014

 


 

Monday, July 28, 2014

 

Mitigating the Risk of Transmission and Environmental Contamination of Transmissible Spongiform Encephalopathies 2013 Annual Report

 


 

Sunday, August 24, 2014

 

*** USAHA 117TH ANNUAL MEETING USDA-APHIS–VS CWD Herd Certification Program Goals TSE PRION October 17 – 23, 2013

 


 

Monday, May 05, 2014

 

*** Member Country details for listing OIE CWD 2013 against the criteria of Article 1.2.2., the Code Commission recommends consideration for listing

 


 

*** OIE GROUP RECOMMENDS THAT SCRAPE PRION DISEASE BE DELISTED, WISHES TO CONTINUE SPREADING IT AROUND THE GLOBE

 


 

Monday, November 30, 2009

 

*** USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE, DOES NOT SURPRISE ME $

 


 

why do we not want to do TSE transmission studies on chimpanzees $

 

5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.

 

snip...

 

R. BRADLEY

 


 

1: J Infect Dis 1980 Aug;142(2):205-8

 

Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.

 

Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.

 

Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.

 

snip...

 

The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.

 

PMID: 6997404

 


 

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.

 

snip...

 

76/10.12/4.6

 


 

Nature. 1972 Mar 10;236(5341):73-4.

 

Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).

 

Gibbs CJ Jr, Gajdusek DC.

 

Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0

 

Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)

 

C. J. GIBBS jun. & D. C. GAJDUSEK

 

National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland

 

SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).

 


 


 

Wednesday, February 16, 2011

 

IN CONFIDENCE

 

SCRAPIE TRANSMISSION TO CHIMPANZEES

 

IN CONFIDENCE

 


 

Sunday, December 12, 2010

 

EFSA reviews BSE/TSE infectivity in small ruminant tissues News Story 2 December 2010

 


 

Sunday, April 18, 2010

 

SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010

 


 

Thursday, December 23, 2010

 

Molecular Typing of Protease-Resistant Prion Protein in Transmissible Spongiform Encephalopathies of Small Ruminants, France, 2002-2009

 

Volume 17, Number 1 January 2011

 


 

Thursday, November 18, 2010

 

Increased susceptibility of human-PrP transgenic mice to bovine spongiform encephalopathy following passage in sheep

 


 

Monday, April 25, 2011

 

Experimental Oral Transmission of Atypical Scrapie to Sheep

 

Volume 17, Number 5-May 2011

 


 

Friday, February 11, 2011

 

Atypical/Nor98 Scrapie Infectivity in Sheep Peripheral Tissues

 


 

Thursday, March 29, 2012

 

atypical Nor-98 Scrapie has spread from coast to coast in the USA 2012

 

NIAA Annual Conference April 11-14, 2011San Antonio, Texas

 


 

*** Canada Increased Atypical Scrapie Detections

 

Press reports indicate that increased surveillance is catching what otherwise would have been unreported findings of atypical scrapie in sheep. In 2009, five new cases have been reported in Quebec, Ontario, Alberta, and Saskatchewan. With the exception of Quebec, all cases have been diagnosed as being the atypical form found in older animals. Canada encourages producers to join its voluntary surveillance program in order to gain scrapie-free status. The World Animal Health will not classify Canada as scrapie-free until no new cases are reported for seven years. The Canadian Sheep Federation is calling on the government to fund a wider surveillance program in order to establish the level of prevalence prior to setting an eradication date. Besides long-term testing, industry is calling for a compensation program for farmers who report unusual deaths in their flocks.

 


 

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.

 


 

P.5.21 Parallels between different forms of sheep scrapie and types of Creutzfeldt-Jakob disease (CJD)

 

Wiebke M. Wemheuer1, Sylvie L. Benestad2, Arne Wrede1, Wilhelm E. Wemheuer3, Tatjana Pfander1, Bjørn Bratberg2, Bertram Brenig3,Walter J. Schulz-Schaeffer1 1University Medical Center Goettingen, Germany; 2Institute of Veterinary Medicine Oslo, Norway; 3Institute of Veterinary Medicine Goettingen, Germany

 

Background: Scrapie in sheep and goats is often regarded as the archetype of prion diseases. In 1998, a new form of scrapie - atypical/Nor98 scrapie - was described that differed from classical scrapie in terms of epidemiology, Western blot profile, the distribution of pathological prion protein (PrPSc) in the body and its stability against proteinase K. In a similar way, distinct disease types exist in sporadic Creutzfeldt-Jakob disease (CJD). They differ with regard to their clinical outcome, Western blot profile and PrPSc deposition pattern in the central nervous system (CNS). Objectives: The comparison of PrPSc deposits in sheep scrapie and human sporadic CJD.

 

Methods: Tissues of the CNS of sheep with classical scrapie, sheep with atypical/Nor98 scrapie and 20 patients with sporadic CJD were examined using the sensitive Paraffin Embedded Tissue (PET) blot method. The results were compared with those obtained by immunohistochemistry. With the objective of gaining information on the protein conformation, the PrPSc of classical and atypical/Nor98 sheep scrapie and sporadic CJD was tested for its stability against denaturation with guanidine hydrochloride (GdnHCl) using a Membrane Adsorption Assay.

 

Results: The PrPSc of atypical/Nor98 scrapie cases and of CJD prion type 1 patients exhibits a mainly reticular/synaptic deposition pattern in the brain and is relatively sensitive to denaturation with GdnHCl. In contrast classical scrapie cases and CJD prion type 2 patients have a more complex PrPSc deposition pattern in common that consists of larger PrPSc aggregates and the PrPSc itself is comparatively stable against denaturation.

 

Discussion: The similarity between CJD types and scrapie types indicates that at least two comparable forms of the misfolded prion protein exist beyond species barriers and can elicit prion diseases. It seems therefore reasonable to classify classical and atypical/Nor98 scrapie - in analogy to the existing CJD types - as different scrapie types.

 


 

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.

 


 

Monday, December 1, 2008

 

When Atypical Scrapie cross species barriers

 


 

Thursday, December 20, 2012

 

OIE GROUP RECOMMENDS THAT SCRAPE PRION DISEASE BE DELISTED, WISHES TO CONTINUE SPREADING IT AROUND THE GLOBE

 


 

Monday, November 30, 2009

 

USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE, DOES NOT SURPRISE ME $

 


 

Saturday, August 02, 2014

 

*** Structural effects of PrP polymorphisms on intra- and inter-species prion transmission

 

In contrast, the scrapie prions used in the deer transmission studies of Greenlee and colleagues were isolated from a sheep encoding A136, ***raising the possibility that deer may be susceptible to multiple scrapie strains.

 

snip...

 

Significance

 

The unpredictable recurrences of prion epidemics, their incurable lethality, and the capacity of animal prions to infect humans, provide significant motivation to ascertain the parameters governing disease transmission. The unprecedented spread, and uncertain zoonotic potential of chronic wasting disease (CWD), a contagious epidemic among deer, elk, and other cervids, is of particular concern. Here we demonstrate that naturally occurring primary structural differences in cervid PrPs differentially impact the efficiency of intra- and interspecies prion transmission. Our results not only deliver new information about the role of primary structural variation on prion susceptibility, but also provide functional support to a mechanism in which plasticity of a tertiary structural epitope governs prion protein conversion and intra- and inter-species susceptibility to prions.-

 

snip...

 


 

*** 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.

 


 

now, decades later ;

 

2012

 

PO-039: A comparison of scrapie and chronic wasting disease in white-tailed deer

 

snip...

 

After a natural route of exposure, 100% of WTD were susceptible to scrapie. Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer exhibited two different molecular profiles: samples from obex resembled CWD whereas those from cerebrum were similar to the original scrapie inoculum. On further examination by WB using a panel of antibodies, the tissues from deer with scrapie exhibit properties differing from tissues either from sheep with scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are strongly immunoreactive when probed with mAb P4, however, samples from WTD with scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4 or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly immunoreactive and samples from WTD with scrapie are strongly positive. This work demonstrates that WTD are highly susceptible to sheep scrapie, but on first passage, scrapie in WTD is differentiable from CWD.

 


 

2011

 

*** After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie.

 

see ;

 

Scrapie in Deer: Comparisons and Contrasts to Chronic Wasting Disease (CWD)

 

Justin J. Greenlee of the Virus and Prion Diseases Research Unit, National Animal Disease Center, ARS, USDA, Ames, IA provided a presentation on scrapie and CWD in inoculated deer.

 

Interspecies transmission studies afford the opportunity to better understand the potential host range and origins of prion diseases. We inoculated white-tailed deer intracranially (IC) and by a natural route of exposure (concurrent oral and intranasal inoculation) with a US scrapie isolate. All deer inoculated by the intracranial route had evidence of PrPSc accumulation and those necropsied after 20 months post-inoculation (PI) (3/5) had clinical signs, spongiform encephalopathy, and widespread distribution of PrPSc in neural and lymphoid tissues. A single deer that was necropsied at 15.6 months PI did not have clinical signs, but had widespread distribution of PrPSc. This highlights the facts that 1) prior to the onset of clinical signs PrPSc is widely distributed in the CNS and lymphoid tissues and 2) currently used diagnostic methods are sufficient to detect PrPSc prior to the onset of clinical signs. The results of this study suggest that there are many similarities in the manifestation of CWD and scrapie in white-tailed deer after IC inoculation including early and widespread presence of PrPSc in lymphoid tissues, clinical signs of depression and weight loss progressing to wasting, and an incubation time of 21-23 months. Moreover, western blots (WB) done on brain material from the obex region have a molecular profile consistent with CWD and distinct from tissues of the cerebrum or the scrapie inoculum. However, results of microscopic and IHC examination indicate that there are differences between the lesions expected in CWD and those that occur in deer with scrapie: amyloid plaques were not noted in any sections of brain examined from these deer and the pattern of immunoreactivity by IHC was diffuse rather than plaque-like. After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie. Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for scrapie by IHC and WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. While two WB patterns have been detected in brain regions of deer inoculated by the natural route, unlike the IC inoculated deer, the pattern similar to the scrapie inoculum predominates.

 


 

Scrapie in Deer: Comparisons and Contrasts to Chronic Wasting Disease (CWD)

 

Justin J. Greenlee of the Virus and Prion Diseases Research Unit, National Animal Disease Center, ARS, USDA, Ames, IA provided a presentation on scrapie and CWD in inoculated deer. Interspecies transmission studies afford the opportunity

 

After a natural route of exposure, 100% of white-tailed deer were susceptible to scrapie. Deer developed clinical signs of wasting and mental depression and were necropsied from 28 to 33 months PI. Tissues from these deer were positive for scrapie by IHC and WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. While two WB patterns have been detected in brain regions of deer inoculated by the natural route, unlike the IC inoculated deer, the pattern similar to the scrapie inoculum predominates.

 


 

2011 Annual Report

 

Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Location: Virus and Prion Research Unit 2011 Annual Report

 

In Objective 1, Assess cross-species transmissibility of transmissible spongiform encephalopathies (TSEs) in livestock and wildlife, numerous experiments assessing the susceptibility of various TSEs in different host species were conducted. Most notable is deer inoculated with scrapie, which exhibits similarities to chronic wasting disease (CWD) in deer suggestive of sheep scrapie as an origin of CWD.

 

snip...

 

4. Accomplishments

 

1. Deer inoculated with domestic isolates of sheep scrapie. Scrapie-affected deer exhibit 2 different patterns of disease associated prion protein. In some regions of the brain the pattern is much like that observed for scrapie, while in others it is more like chronic wasting disease (CWD), the transmissible spongiform encephalopathy typically associated with deer. This work conducted by ARS scientists at the National Animal Disease Center, Ames, IA suggests that an interspecies transmission of sheep scrapie to deer may have been the origin of CWD. This is important for husbandry practices with both captive deer, elk and sheep for farmers and ranchers attempting to keep their herds and flocks free of CWD and scrapie.

 


 

White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection

 

snip...

 

This work demonstrates for the first time that white-tailed deer are susceptible to sheep scrapie by potential natural routes of inoculation. In-depth analysis of tissues will be done to determine similarities between scrapie in deer after intracranial and oral/intranasal inoculation and chronic wasting disease resulting from similar routes of inoculation.

 

see full text ;

 


 

Infectivity and abnormal prion protein in tissues from sheep exposed to atypical scrapie (ongoing)

 

Last updated: 22 July 2007

 

This project will establish distribution of abnormal PrP and infectivity in sheep tissues, such as blood, muscle, central nervous system(CNS) and milk.

 

Study Duration: July 2007 to June 2013

 

Contractor: ENVT

 

Project Code: FS231050 (M03058)

 

Background

 

Recently identified atypical scrapie cases in sheep represent an emerging TSE of which little is known. Incidence in EU countries seems to vary between 3 and 11 per 10,000 tested animals. However, because there is probably a lack of sensitivity in screening tests towards this particular TSE, this value is likely to be an underestimation. There is no consistent information concerning the abnormal PrP or infectivity distribution in peripheral tissues of atypical cases. This absence of data, combined with the involvement of ARR/ARR (genotype most resistant to BSE) animals that were believed to be resistant to TSE, represent a major concern with regards to the efficiency of the current food protection policy against TSE.

 

Research Approach

 

This project will establish distribution of abnormal PrP using various tools including Immunohistochemistry, and infectivity (using transgenic mice model) in sheep tissues such as blood, muscle, central nervous system(CNS) and milk. The research will give consideration to the fact that atypical cases could be either a spontaneous affection from CNS origin or an acquired infectious disease resulting from an oral contamination.

 

Andréoletti, O., Orge, L., Benestad, S.L., Beringue, V., Litaise, C., Simon, S., Le Dur, A., Laude, H., Simmons, H., Lugan, S., Corbière, F., Costes, P., Morel, N., Schelcher, F. & Lacroux, C. (2011) Atypical/Nor98 scrapie infectivity in sheep peripheral tissues. Published online PLoS Pathogens 7: e1001285

 


 

Exploring permeability of human species barrier to circulating TSE agent (ongoing)

 

Last updated: 17 March 2007

 

This research project aims to explore the abilities of a number of different TSE isolates including cattle BSE, atypical BSE in cattle, atypical scrapie in sheep and chronic wasting disease in deer. It will also examine the potential alteration of permeability of human species barrier for prions that have adapted to a species other than their natural host, for example experimental BSE in sheep.

 

Study Duration: March 2007 to February 2013

 

Contractor: ENVT

 

Project Code: FS231051 (M03043)

 

Background

 

The species barrier has appeared to be efficient for limiting propagation of the TSE agent between animal species. One consequence of such a barrier is the apparent absence of natural transmission from a number of animal TSE agents to humans, however, that statement remains essentially based on epidemiological observations. Very little data is available in this field, however, in the case of cattle BSE its ability to cross the species barrier has been demonstrated. The recent discovery of atypical forms of BSE in cattle as well as atypical forms of scrapie in sheep raise the question of their transmissibility to humans.

 

Research Approach

 

The research will use Enzyme-Linked ImmunoSorbent Assays and western blot techniques to characterisation phenotypic features that are linked to a strain of TSE agent.

 

Padilla, D., Béringue, V., Espinosa, J.C., Andréoletti, O., Jaumain, E., Reine, F., Herzog, L., Gutierrez-Adan, A., Pintado B., Laude H. & Torres J.M. (2011) Sheep and goat BSE propagate more efficiently than cattle BSE in human PrP transgenic mice. Published online PLoS Pathogens 7: e1001319 Espinosa, J.C., Herva, M.E., Andréoletti, O., Padilla, D., Lacroux,C., Cassard, H., Lantier, I., Castilla, J. & Torres, J.M. (2009) Transgenic mice expressing porcine prion protein resistant to classical scrapie but susceptible to sheep bovine spongiform encephalopathy and atypical scrapie. Emerging Infectious Diseases, 15, 1214-21

 


 

Occurrence and quantification of CNS contamination on bovine head meat after slaughter (ongoing)

 

Last updated: 12 October 2008

 

This project aims to asses the risk of CNS contamination of head meat from cattle slaughtered in UK abattoirs should a slaughtered animal be infected with BSE.

 

Study Duration: October 2008 to March 2013

 

Contractor: Department of clinical veterinary science, University of Bristol

 

Project Code: FS235009 (M03066)

 

Background

 

During the slaughter and dressing of bovines, there are several conventional practices that disrupt the integrity of the central nervous system, (CNS) and have the potential to disseminate it on edible meat. This applies not only to carcass meat, but also to head meat, possibly contaminated by brain material (which is specified risk material) at, or following, stunning an animal with a captive bolt gun.

 

Head removal also is an invasive procedure, as the spinal cord is severed, and there may be leakage of brain tissue through the foramen magnum. There is no information on the prevalence or amount of CNS contamination of head meat from cattle slaughtered in UK abattoirs and therefore no basis for an assessment of public health risk from these sources should a slaughtered animal be infected with BSE.

 

There are many factors that have potential to introduce substantial variability in the degree of contamination of head meat, including abattoir practices and subsequent moving and storage of heads if harvesting meat is performed off-line or in separate premises.

 

Research Approach A comprehensive evaluation of the contamination of bovine heads and head meat by CNS material will be based on current industry practices and on a simulation of procedures that would be used if heads were processed at cutting plants.

 

Contamination will be quantified using CNS marker protein(s) and will be measured on head meat after different handling and harvesting methods currently used. The effects of bunging the captive bolt shooting hole and the foramen magnum (including after brain stem sampling) on contamination of heads will be determined. The effects of surface dehydration of heads during storage on the detection and amount of CNS material will be measured. Two options to simulate loading, within-plant/road transport, and unloading of heads being transferred to a cutting plant will be explored.

 

A best practice for the procedures involved in shipping heads will be identified and contamination levels after transfer will be compared with that on heads harvested on-line.

 

Results Additional Info Dissemination Published Papers

 

 

 


 

Thursday, February 27, 2014

 

BEEF, CANCER, PRIONS, AND OTHER DANGEROUS AND DEADLY PATHOGENS, APPARENTLY, IT'S WHAT'S FOR DINNER

 


 

Thursday, March 6, 2014

 

TEXAS RECALL LIST MASSIVE FROM DEAD STOCK DOWNER CANCER COWS OFFAL from Class I Recall 002-2014 and 013-2014 Health Risk: High Jan 13, 2014 and Feb 8, 2014 shipped to Texas, Florida, and Illinois UPDATE FEBRUARY 14, 2014

 


 

Thursday, March 20, 2014

 

JACK IN THE BOX NOW CAUGHT UP IN MASSIVE RANCHO DEAD STOCK DOWNER CANCER COW RECALL

 


 

Thursday, June 12, 2014

 

Missouri Firm Recalls Ribeye and Carcass Products That May Contain Specified Risk Materials 4,012 pounds of fresh beef products because the dorsal root ganglia may not have been completely removed

 


 

Saturday, June 14, 2014

 

Rep. Rosa DeLauro (D-CT) Calls for Briefing on Beef Recalled for Mad Cow Potential Rep. Rosa DeLauro (D-CT)

 


 

Tuesday, August 19, 2014

 

Former Rancho Employees Charged With 11 Felonies processed meat from 101 condemned cattle, including 79 with “cancer eye''

 


 

Thursday, November 28, 2013

 

Department of Justice Former Suppliers of Beef to National School Lunch Program Settle Allegations of Improper Practices and Mistreating Cows

 


 

seems USDA NSLP et al thought that it would be alright, to feed our children all across the USA, via the NSLP, DEAD STOCK DOWNER COWS, the most high risk cattle for mad cow type disease, and other dangerous pathogens, and they did this for 4 years, that was documented, then hid what they did by having a recall, one of the largest recalls ever, and they made this recall and masked the reason for the recall due to animal abuse (I do not condone animal abuse), not for the reason of the potential for these animals to have mad cow BSE type disease (or other dangerous and deadly pathogens). these TSE prion disease can lay dormant for 5, 10, 20 years, or longer, WHO WILL WATCH OUR CHILDREN FOR THE NEXT 5 DECADES FOR CJD ???

 

Saturday, September 21, 2013

 

Westland/Hallmark: 2008 Beef Recall A Case Study by The Food Industry Center January 2010 THE FLIM-FLAM REPORT

 


 

DID YOUR CHILD CONSUME SOME OF THESE DEAD STOCK DOWNER COWS, THE MOST HIGH RISK FOR MAD COW DISEASE ??? this recall was not for the welfare of the animals. ...tss you can check and see here ; (link now dead, does not work...tss)

 


 

try this link ;

 


 

Sunday, November 13, 2011

 

*** California BSE mad cow beef recall, QFC, CJD, and dead stock downer livestock

 


 

Thursday, February 13, 2014

 

HSUS VS USDA ET AL BAN DOWNER CALVES FOR HUMAN CONSUMPTION (*veal) and potential BSE risk factor there from

 


 

what’s the big secret about the age and history of this poor gentleman ???

 

MAD COW COVER UP USA, THE EVIDENCE MOUNTS $$$

 

Monday, June 02, 2014

 

Confirmed Human BSE aka mad cow Variant CJD vCJD or nvCJD Case in Texas

 


 

*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years

 

Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3

 


 

New studies on the heat resistance of hamster-adapted scrapie agent: Threshold survival after ashing at 600°C suggests an inorganic template of replication

 


 

Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production

 


 

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

 


 

A Quantitative Assessment of the Amount of Prion Diverted to Category 1 Materials and Wastewater During Processing

 


 

Rapid assessment of bovine spongiform encephalopathy prion inactivation by heat treatment in yellow grease produced in the industrial manufacturing process of meat and bone meals

 


 

PPo4-4:

 

Survival and Limited Spread of TSE Infectivity after Burial

 


 

AD.63:

 

Susceptibility of domestic cats to chronic wasting disease

 

Amy V.Nalls,1 Candace Mathiason,1 Davis Seelig,2 Susan Kraft,1 Kevin Carnes,1 Kelly Anderson,1 Jeanette Hayes-Klug1 and Edward A. Hoover1 1Colorado State University; Fort Collins, CO USA; 2University of Minnesota; Saint Paul, MN USA

 

Domestic and nondomestic cats have been shown to be susceptible to feline spongiform encephalopathy (FSE), almost certainly caused by consumption of bovine spongiform encephalopathy (BSE)-contaminated meat. Because domestic and free-ranging nondomestic felids scavenge cervid carcasses, including those in areas affected by chronic wasting disease (CWD), we evaluated the susceptibility of the domestic cat (Felis catus) to CWD infection experimentally. Cohorts of 5 cats each were inoculated either intracerebrally (IC) or orally (PO) with CWD-infected deer brain. At 40 and 42 mo post-inoculation, two IC-inoculated cats developed signs consistent with prion disease, including a stilted gait, weight loss, anorexia, polydipsia, patterned motor behaviors, head and tail tremors, and ataxia, and progressed to terminal disease within 5 mo. Brains from these two cats were pooled and inoculated into cohorts of cats by IC, PO, and intraperitoneal and subcutaneous (IP/SC) routes. Upon subpassage, feline-adapted CWD (FelCWD) was transmitted to all IC-inoculated cats with a decreased incubation period of 23 to 27 mo. FelCWD was detected in the brains of all the symptomatic cats by western blotting and immunohistochemistry and abnormalities were seen in magnetic resonance imaging, including multifocal T2 fluid attenuated inversion recovery (FLAIR) signal hyper-intensities, ventricular size increases, prominent sulci, and white matter tract cavitation. Currently, 3 of 4 IP/SQ and 2 of 4 PO inoculared cats have developed abnormal behavior patterns consistent with the early stage of feline CWD.

 

*** These results demonstrate that CWD can be transmitted and adapted to the domestic cat, thus raising the issue of potential cervid-to- feline transmission in nature.

 


 

www.landesbioscience.com

 

PO-081: Chronic wasting disease in the cat— Similarities to feline spongiform encephalopathy (FSE)

 


 


 

FELINE SPONGIFORM ENCEPHALOPATHY FSE

 


 


 

Chronic Wasting Disease Susceptibility of Four North American Rodents

 

Chad J. Johnson1*, Jay R. Schneider2, Christopher J. Johnson2, Natalie A. Mickelsen2, Julia A. Langenberg3, Philip N. Bochsler4, Delwyn P. Keane4, Daniel J. Barr4, and Dennis M. Heisey2 1University of Wisconsin School of Veterinary Medicine, Department of Comparative Biosciences, 1656 Linden Drive, Madison WI 53706, USA 2US Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison WI 53711, USA 3Wisconsin Department of Natural Resources, 101 South Webster Street, Madison WI 53703, USA 4Wisconsin Veterinary Diagnostic Lab, 445 Easterday Lane, Madison WI 53706, USA *Corresponding author email: cjohnson@svm.vetmed.wisc.edu

 

We intracerebrally challenged four species of native North American rodents that inhabit locations undergoing cervid chronic wasting disease (CWD) epidemics. The species were: deer mice (Peromyscus maniculatus), white-footed mice (P. leucopus), meadow voles (Microtus pennsylvanicus), and red-backed voles (Myodes gapperi). The inocula were prepared from the brains of hunter-harvested white-tailed deer from Wisconsin that tested positive for CWD. Meadow voles proved to be most susceptible, with a median incubation period of 272 days. Immunoblotting and immunohistochemistry confirmed the presence of PrPd in the brains of all challenged meadow voles. Subsequent passages in meadow voles lead to a significant reduction in incubation period. The disease progression in red-backed voles, which are very closely related to the European bank vole (M. glareolus) which have been demonstrated to be sensitive to a number of TSEs, was slower than in meadow voles with a median incubation period of 351 days. We sequenced the meadow vole and red-backed vole Prnp genes and found three amino acid (AA) differences outside of the signal and GPI anchor sequences. Of these differences (T56-, G90S, S170N; read-backed vole:meadow vole), S170N is particularly intriguing due its postulated involvement in "rigid loop" structure and CWD susceptibility. Deer mice did not exhibit disease signs until nearly 1.5 years post-inoculation, but appear to be exhibiting a high degree of disease penetrance. White-footed mice have an even longer incubation period but are also showing high penetrance. Second passage experiments show significant shortening of incubation periods. Meadow voles in particular appear to be interesting lab models for CWD. These rodents scavenge carrion, and are an important food source for many predator species. Furthermore, these rodents enter human and domestic livestock food chains by accidental inclusion in grain and forage. Further investigation of these species as potential hosts, bridge species, and reservoirs of CWD is required.

 


 

please see ;

 


 

UPDATED CORRESPONDENCE FROM AUTHORS OF THIS STUDY I.E. COLBY, PRUSINER ET AL, ABOUT MY CONCERNS OF THE DISCREPANCY BETWEEN THEIR FIGURES AND MY FIGURES OF THE STUDIES ON CWD TRANSMISSION TO CATTLE ;

 

----- Original Message -----

 

From: David Colby To: flounder9@verizon.net

 

Cc: stanley@XXXXXXXX

 

Sent: Tuesday, March 01, 2011 8:25 AM

 

Subject: Re: FW: re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author Affiliations

 

Dear Terry Singeltary,

 

Thank you for your correspondence regarding the review article Stanley Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner asked that I reply to your message due to his busy schedule. We agree that the transmission of CWD prions to beef livestock would be a troubling development and assessing that risk is important. In our article, we cite a peer-reviewed publication reporting confirmed cases of laboratory transmission based on stringent criteria. The less stringent criteria for transmission described in the abstract you refer to lead to the discrepancy between your numbers and ours and thus the interpretation of the transmission rate. We stand by our assessment of the literature--namely that the transmission rate of CWD to bovines appears relatively low, but we recognize that even a low transmission rate could have important implications for public health and we thank you for bringing attention to this matter. Warm Regards, David Colby -- David Colby, PhDAssistant Professor Department of Chemical Engineering University of Delaware

 

===========END...TSS==============

 

> First transmission of CWD to transgenic mice over-expressing bovine prion protein gene (TgSB3985)

 

PRION 2014 - PRIONS: EPIGENETICS and NEURODEGENERATIVE DISEASES – Shaping up the future of prion research

 

Animal TSE Workshop 10.40 – 11.05 Talk Dr. L. Cervenakova First transmission of CWD to transgenic mice over-expressing bovine prion protein gene (TgSB3985)

 


 

Thursday, November 21, 2013

 

*** Assessing the susceptibility of transgenic mice over-expressing deer prion protein to bovine spongiform encephalopathy

 

The present study was designed to assess the susceptibility of the prototypic mouse line, Tg(CerPrP)1536+/- to bovine spongiform encephalopathy (BSE) prions, which have the ability to overcome species barriers. Tg(CerPrP)1536+/- mice challenged with red deer-adapted BSE resulted in a 90-100% attack rates, BSE from cattle failed to transmit, indicating agent adaptation in the deer.

 


 

P.126: Successful transmission of chronic wasting disease (CWD) into mice over-expressing bovine prion protein (TgSB3985)

 

Larisa Cervenakova,1 Christina J Sigurdson,2 Pedro Piccardo,3 Oksana Yakovleva,1 Irina Vasilyeva,1 Jorge de Castro,1 Paula Saá,1 and Anton Cervenak1 1American Red Cross, Holland Laboratory; Rockville, MD USA; 2University of California; San Diego, CA USA; 3Lab TSE/OBRR /CBER/FDA; Rockville, MD USA

 

Keywords: chronic wasting disease, transmission, transgenic mouse, bovine prion protein

 

Background. CWD is a disease affecting wild and farmraised cervids in North America. Epidemiological studies provide no evidence of CWD transmission to humans. Multiple attempts have failed to infect transgenic mice expressing human PRNP gene with CWD. The extremely low efficiency of PrPCWD to convert normal human PrPC in vitro provides additional evidence that transmission of CWD to humans cannot be easily achieved. However, a concern about the risk of CWD transmission to humans still exists. This study aimed to establish and characterize an experimental model of CWD in TgSB3985 mice with the following attempt of transmission to TgHu mice.

 

Materials and Methods. TgSB3985 mice and wild-type FVB/ NCrl mice were intracranially injected with 1% brain homogenate from a CWD-infected Tga20 mouse (CWD/Tga20). TgSB3985 and TgRM (over-expressing human PrP) were similarly injected with 5% brain homogenates from CWD-infected white-tailed deer (CWD/WTD) or elk (CWD/Elk). Animals were observed for clinical signs of neurological disease and were euthanized when moribund. Brains and spleens were removed from all mice for PrPCWD detection by Western blotting (WB). A histological analysis of brains from selected animals was performed: brains were scored for the severity of spongiform change, astrogliosis, and PrPCWD deposition in ten brain regions.

 

Results. Clinical presentation was consistent with TSE. More than 90% of TgSB3985 and wild-type mice infected with CWD/Tga20, tested positive for PrPres in the brain but only mice in the latter group carried PrPCWD in their spleens. We found evidence for co-existence or divergence of two CWD/ Tga20 strains based on biochemical and histological profiles. In TgSB3985 mice infected with CWD-elk or CWD-WTD, no animals tested positive for PrPCWD in the brain or in the spleen by WB. However, on neuropathological examination we found presence of amyloid plaques that stained positive for PrPCWD in three CWD/WTD- and two CWD/Elk-infected TgSB3985 mice. The neuropathologic profiles in CWD/WTD- and CWD/Elkinfected mice were similar but unique as compared to profiles of BSE, BSE-H or CWD/Tg20 agents propagated in TgSB3985 mice. None of CWD-infected TgRM mice tested positive for PrPCWD by WB or by immunohistochemical detection.

 

Conclusions. To our knowledge, this is the first established experimental model of CWD in TgSB3985. We found evidence for co-existence or divergence of two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice. Finally, we observed phenotypic differences between cervid-derived CWD and CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway to characterize these strains.

 

P.89: Prions survive long-term burial in soil with some groundwater dissemination

 

Allister JA Smith,1 Karen Fernie,1 Ben Maddison,2 Keith Bishop,2 Kevin Gough,3 and Robert A Somerville1 1The Roslin Institute; University of Edinburgh; Edinburgh, UK; 2ADAS Biotechnology Group, University of Nottingham; Nottingham, UK; 3University of Nottingham; Nottingham, UK

 

An intrinsic property of prions is their extreme resistance to degradation. When they are deposited within the environment, whether from inappropriate disposal by man or from fallen diseased livestock, there is the potential to further propagate cases of disease for many years. It is evidenced that the spread of scrapie in sheep and chronic wasting disease in deer have occurred in this manner.

 

We mimicked such scenarios under large-scale field conditions to determine the extent to which TSE infectivity survives or disseminates in soil and soil water over five years. The mouse passaged BSE strain, 301V, was used to spike buried bovine heads, or was buried as an uncontained bolus in large soil-filled lysimeters. Two soils were examined, a free-draining sandy loam and a water-retentive clay loam.

 

Infectivity, determined by bioassay in mice, was recovered from all heads exhumed annually for 5 years from both soil types, with little reduction in the amount of infectivity over time. Small amounts of infectivity were found in soil samples immediately surrounding the heads but not in samples remote from them. Commensurate with this there was no evidence of significant lateral movement of infectivity from the bolus buried in a large soil mass. However large amounts of infectivity were recovered at the original bolus burial site in both soils. There was limited vertical upward movement of infectivity from the bolus buried in clay and downward movement from the bolus buried in sand perhaps reflecting the clay soils propensity to flood.

 

Throughout the course of the experiment rainwater particulate from several lysimeters was trapped on glass-fibre filters. Extracts from these filters were subject to serial PMCA (protein misfolding cyclic amplification) which was optimised using 301V-spiked samples and blinded controls. All positive and negative control samples were correctly determined. We have tested 44 samples from rainwater passed through the clay lysimeter filters, and found 9 positive samples, mainly from the initial 8 months of the experiment.

 

We conclude that TSE infectivity is likely to survive burial for long time periods with minimal loss of infectivity and limited movement from the original burial site. However PMCA results have shown that there is the potential for rainwater to elute TSErelated material from soil which could lead to the contamination of a wider area. These experiments reinforce the importance of risk assessment when disposing of TSE risk materials.

 

P.121: Efficient transmission of prion disease through environmental contamination

 

Sandra Pritzkow, Rodrigo Morales, and Claudio Soto Mitchell Center for Alzheimer’s disease and related Brain disorders; University of Texas Medical School at Houston; Hourston, TX USA

 

Chronic wasting disease (CWD) is a prion disorder effecting captive and free-ranging deer and elk. The efficient propagation suggests that horizontal transmission through contaminated environment may play an important role. It has been shown that infectious prions enter the environment through saliva, feces, urine, blood or placenta tissue from infected animals, as well as by carcasses from diseased animals and can stay infectious inside soil over several years.

 

82 Prion Volume 8 Supplement

 

We hypothesize that environmental components getting in contact with infectious prions can also play a role for the horizontal transmission of prion diseases. To study this issue, surfaces composed of various environmentally relevant materials were exposed to infectious prions and the attachment and retention of infectious material was studied in vitro and in vivo. We analyzed polypropylene, glass, stainless steel, wood, stone, aluminum, concrete and brass surfaces exposed to 263K-infected brain homogenate. For in vitro analyses, the material was incubated in serial dilutions of 263K-brain homogenate, washed thoroughly and analyzed for the presence of PrPSc by PMCA. The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.

 

In addition, in order to study the transmission in a more natural setting, we exposed a group of hamster to habit in the presence of spheres composed of various materials that were pretreated with 263K prions. Many of the hamsters exposed to these contaminated materials developed typical signs of the disease that were confirmed by immunohistological and biochemical analyses.

 

These findings suggest that various surfaces can efficiently bind infectious prions and act as carriers of infectivity, suggesting that diverse elements in the environment may play an important role in horizontal prion transmission.

 

P.138: Phenotypic diversity in meadow vole (Microtus pennsylvanicus) prion diseases following challenge with chronic wasting disease isolates

 

Christopher J Johnson,1 Christina M Carlson,1,2 Jay R Schneider,1 Jamie K Wiepz,1 Crystal L Meyerett-Reid,3 Mark D Zabel,3 Joel A Pedersen,2 and Dennis M Heisey1 1USGS National Wildlife Health Center; Madison, WI USA; 2University of Wisconsin— Madison; Madison, WI USA; 3Colorado State University; Fort Collins, CO USA

 

Chronic wasting disease (CWD), a prion disease of cervids (deer, elk and moose), is spreading unchecked through large sections of North America. Transmission of CWD among cervids is especially facile and can occur through direct animal-toanimal contact and indirectly through contact with prions shed from infected animals. The disease transmission threat posed by CWD to other wildlife species remains unknown, but other species are inevitably exposed to CWD by consumption of infectious materials and through contact with environmental CWD contamination.

 

In this study, we investigated the transmission and adaptation of various white-tailed deer CWD isolates in the meadow vole (Microtus pennsylvanicus), a native North American rodent that is sympatric with current CWD epizootics that we have previously established is susceptible to CWD. We found that serial subpassage of CWD from white-tailed deer homozygous for glycine at position 96 (96GG) of the prion protein in meadow voles resulted in the selection of a single prion strain that was characterized by homogeneity in incubation period, abnormal prion protein (PrPTSE) glycoform ratio, lesion profile and PrPTSE deposition pattern. In contrast, passage of CWD from heterozygous 96GS genotype deer produced four unique disease phenotypes upon first passage. Subpassage of these types ultimately resulted in selection of a single strain by third passage that was distinct from the 96GG genotype CWD-derived strain.

 

We also establish that meadow voles are susceptible to CWD via peripheral challenge, albeit with lower attack rates and longer incubation periods. Interestingly, oral challenge of meadow voles with CWD resulted in subclinical infection in primary passage animals, but manifested as clinical prion disease upon subpassage.

 

Our data establish that meadow voles are permissive to CWD via peripheral exposure route, suggesting they could serve as an environmental reservoir for CWD. Additionally, our data are consistent with the hypothesis that at least two strains of CWD circulate in naturally-infected cervid populations and provide evidence that meadow voles are a useful tool for CWD strain typing.

 

P.141: Abundant prion shedding in CWD-infected deer revealed by Realtime conversion

 

Edward A Hoover,1 Davin M Henderson,1 Nathaniel D Denkers,1 Candace K Mathiason,1 Matteo Manca,2,3 and Byron Caughey2 1Prion Research Center, Colorado State University; Fort Collins, CO USA; 2Laboratory of Persistent Viral Diseases, NI AID; Hamilton, MT USA; 3Department of Biomedical Sciences, University of Cagliari; Monserrato, Italy

 

Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature. While the presence of infectious prions in body fluids and excreta of infected cervids has been demonstrated by bioassay, the dynamics, magnitude, and consequences of prion shedding remain unknown. The present studies were undertaken to determine the kinetics, duration, and magnitude of prion shedding in infected white-tailed deer.

 

Materials and Methods. Longitudinal samples were collected from white-tailed deer over a 2-year span after either oral (n=11)] aerosol (n = 6) CWD exposure. The assay protocol employed phosphotungstic acid precipitation of either whole saliva or the pelleted fraction of urine to seed recombinant Syrian hamster prion PrP substrate in RT-QuIC reactions. Prion seeding activity was assayed in 8 replicates of each sample employing thioflavin T detection in a 96-well plate-based fluorometer. Prion seeding reaction rate was determined by taking the inverse of the time at which samples exceeded a threshold of 5 standard deviations above the mean fluorescence of negative controls (1/time to threshold). Seeding activity was quantitated by comparing the realtime conversion reaction rate to a standard curve derived from a reference bioassayed brain pool homogenate from deer with terminal CWD.

 

Results. We analyzed >200 longitudinally collected, blinded, then randomized saliva and urine samples from 17 CWDinfected and 3 uninfected white-tailed deer. We detected prion shedding as early as 3 months post exposure and sustained thereafter throughout the disease course in both aerosol and orally exposed deer. The incidence of non-specific false positive results from >500 saliva and urine samples from negative control deer was 0.8%. By comparing real-time reaction rates for these body fluids to a bioassayed serially diluted brain control, we estimated that ≤1 ml of saliva or urine from pre-symptomatic infected deer constitutes a lethal infectious prion dose.

 

Conclusion. CWD prions are shed in saliva and urine of infected deer as early as 3 months post infection and throughout the subsequent >1.5 year course of infection. In current work we are examining the relationship of prionemia to excretion and the impact of excreted prion binding to surfaces and particulates in the environment.

 

Acknowledgments. Support: NIH-RO1-NS-061902; Morris Animal Foundation D12ZO-045

 

P.154: Urinary shedding of prions in Chronic Wasting Disease infected white-tailed deer

 

Nathaniel D Denkers,1 Davin M Henderson, 1 Candace K Mathiason,1 and Edward A Hoover1 1Prion Research Center, Department of Microbiology, Immunology, and Pathology, Colorado State University; Fort Collins, CO USA

 

Background/Introduction. Chronic wasting disease (CWD) is unique among prion diseases in its efficient lateral transmission in nature, yet the dynamics and magnitude of shedding and its immediate and long term consequences remain unknown. The present study was designed to determine the frequency and time span in which CWD prions are shed in urine from infected white-tailed deer using adapted real-time quaking-induced conversion (RT-QuIC) methodology.

 

Materials and Methods. Longitudinal urine samples were collected by free catch or catheterization over a 2-year period from oral-route infected [CWD+ (n = 11)] and aerosol-route-infected [CWD+ (n = 6); CWD- (n = 3)] white-tailed deer. High speed centrifugation pelleted material from 500 µl of urine was treated with sodium phosphotungstic acid (Na-PTA), resuspended in 0.05% SDS buffer, and used as seed in RT-QuIC assays employing recombinant Syrian hamster prion PrP substrate. Eight (8) replicates of each sample were run and prion seeding activity was recorded as thioflavin T binding fluorescence (480 nm emission) using a fluorimeter-shaker. Samples were considered positive if they crossed an established threshold (5 standard deviations above the negative mean fluorescence).

 

Results. In our oral-route inoculation studies, prion seeding activity has been demonstrated in urine collected at 6 months post-inoculation in 6 of 10 deer (11 of 80 replicates; 14%), and intermittently at later time points in all 11 CWD+ exposed deer. Our aerosol-route inoculation studies also showed prion seeding activity in urine collected at 6 months post-inoculation in 1 of 2 deer (3 of 16 replicates; 19%), and intermittently at later time points in 4 of 6 CWD+ exposed deer. Urine from sham-inoculated control deer and all baseline samples yielded 3 false-positive prion seeding activities (3 of 352 replicates; 0.8%).

 

Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC) are shed in urine of infected deer as early as 6 months post inoculation and throughout the subsequent disease course. Further studies are in progress refining the real-time urinary prion assay sensitivity and we are examining more closely the excretion time frame, magnitude, and sample variables in relationship to inoculation route and prionemia in naturally and experimentally CWD-infected cervids.

 

Acknowledgments. Support: NIH: RO1-NS-061902 and Morris Animal Foundation: D12ZO-045

 

P.158: Structurally and phenotypically different prions in CWD-infected white-tailed deer

 

Martin L Daus, Peter Lasch, and Michael Beekes Robert Koch-Institut; Berlin, Germany

 

Prions can exist as multiple strains within mammals. We could detect, for the first time, two distinct chronic wasting disease (CWD) isolates in white-tailed deer (WTD).

 

WTD had been challenged with CWD from either mule deer (MD) or WTD. Brain-derived prions from MD-infected WTD and WTD-infected WTD could be distinguished by biochemical, biophysical and biological methods. PK-mediated limited proteolysis at different pH-values indicated conformational differences between pathological prion proteins (PrPTSE) from MD-infected WTD and WTD-infected WTD. More specifically, Fouriertransform infrared microspectroscopy revealed secondary structure differences between highly purified PrPTSE extracts from MD-infected WTD and WTD-infected WTD. Different sedimentation velocities of PrPTSE in gradient centrifugations provided additional evidence for structure differences between prions from MD-infected WTD and WTD-infected WTD. Brain homogenate from WTD-infected WTD showed a substantially lower seeding activity on cellular prion protein (PrPC) of Syrian hamsters in protein misfolding cyclic amplification (PMCA) than its conformationally distinct counterpart from MD-infected WTD. When hamsters were intracerebrally inoculated with brain tissue from MD-infected WTD disease could be transmitted, which was not observed after similar inoculation with brain homogenate from WTD-infected WTD. In an ongoing macaque-study both CWD-isolates are currently being further tested for their transmissibility to primates.

 

P.163: Bayesian hierarchical modeling of chronic wasting disease in free-ranging white-tailed deer in the eastern U.S.

 

Tyler S Evans1 and W David Walter2 1Pennsylvania Cooperative Fish and Wildlife Research Unit; The Pennsylvania State University; University Park, PA USA; 2US Geological Survey; Pennsylvania Cooperative Fish and Wildlife Research Unit; The Pennsylvania State University; University Park, PA USA

 

Introduction. Chronic wasting disease (CWD) is a prion disease that affects both free-ranging and captive cervid populations. In the past 45 years, CWD has spread from a single region in Colorado to all bordering states, as well as Canada, the Midwest and the northeastern United States. In 2005, CWD was detected in the eastern U.S. in a free-ranging white-tailed deer (Odocoileus virginianus) killed by a vehicle in West Virginia followed by positives from Virginia, Maryland, and Pennsylvania. Although considerable information has been learned about CWD in wildlife from several areas of the U.S. and Canada, little information is available on spatial epidemiology of disease in the eastern U.S.

 

Materials and Methods. In order to develop a CWD surveillance plan for the region, we determined covariates and the best scale for analysis by exploring habitat use and estimating the mean size of home range for deer in the central Appalachian region (6 km2). We conducted Bayesian hierarchical modeling in WinBUGS on 24 a priori models using 11,320 free-ranging white-tailed deer (69 positive, 11,251 negative) that have been tested for CWD since 2005. Testing for CWD was conducted using standard protocols on a variety of tissues extracted from hunter-harvested deer that included retropharyngeal lymph nodes, tonsil lymph nodes, and the medulla oblongata sectioned at the obex.

 

Results. We found 94% of models weights were accounted for in our top model that identified habitats such as developed and open as covariates that increased the odds of infection for CWD in this region. Contrary to research in the endemic area of Colorado, we did not identify clay soil as a significant predictor of disease even though clay soil ranged from 9% to 19% in our study samples. Furthermore, contrary to results from the recent expansion of CWD into the agricultural Midwestern U.S. (Wisconsin, Illinois), we identified developed and open habitats were better predictors of disease occurrence compared to forest habitat considered more critical to deer population dynamics in the U.S.

 

Conclusions. Our results suggested that the odds of infection for CWD is likely controlled by areas that congregate deer thus increasing direct transmission (deer-to-deer interactions) or indirect transmission (deer-to-environment) by sharing or depositing infectious prion proteins in these preferred habitats. Epidemiology of CWD in the eastern U.S. is likely controlled by separate factors than found in the Midwestern and endemic areas for CWD and can assist in performing more efficient surveillance efforts for the region.

 

P.178: Longitudinal quantitative analysis of CWD prions shed in saliva of deer

 

Davin M Henderson, Nina Garbino, Nathaniel D Denkers, Amy V Nalls, Candace K Mathiason, and Edward A Hoover Prion Research Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University; Fort Collins, CO USA

 

Background/Introduction. Chronic Wasting Disease (CWD) is an emergent rapidly spreading fatal prion disease of cervids (deer, elk and moose). CWD has now been identified in 22 States (including two new states within the last year), 2 Canadian provinces, and South Korea. Shedding of infectious prions in excreta (saliva, urine, feces) may be an important factor in CWD transmission. Here we apply an adapted version of a rapid in vitro assay [real-time quaking-induced conversion (RT-QuIC)] to determine the time of onset, length, pattern, and magnitude of prion shedding in saliva of infected deer.

 

Materials and Methods. The RT-QuIC assay was performed as previously described in Henderson et al. PLoS-One (2013). Saliva samples were quantitated by comparison to a RT-QuIC reaction rate standard curve of a bioassayed obex sample from a terminally ill cervid.

 

Results. To better understand the onset and length of CWD prion shedding we analyzed >150 longitudinally collected, blinded, then randomized saliva samples from 17 CWD-infected and 3 uninfected white-tailed deer. We observed prion shedding, as detected by the RT-QuIC assay, as early as 3 months from inoculation and sustained shedding throughout the disease course in both aerosol and orally exposed deer. We estimated the infectious lethal dose of prions shed in saliva from infected deer by comparing real-time reaction rates of saliva samples to a bioassayed serially diluted brain control. Our results indicate that as little as 1 ml of saliva from pre-symptomatic infected deer constitutes a lethal CWD prion dose.

 

Conclusions. During the pre-symptomatic stage of CWD infection and throughout the course of disease deer may be shedding multiple LD50 doses per day in their saliva. CWD prion shedding through saliva and excreta may account for the unprecedented spread of this prion disease in nature.

 

Acknowledgments. Supported by NIH grant RO1-NS-061902 and grant D12ZO-045 from the Morris Animal Foundation.

 


 

PRION 2014 CONFERENCE

 

CHRONIC WASTING DISEASE CWD

 

A FEW FINDINGS ;

 

Conclusions. To our knowledge, this is the first established experimental model of CWD in TgSB3985. We found evidence for co-existence or divergence of two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice. Finally, we observed phenotypic differences between cervid-derived CWD and CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway to characterize these strains.

 

We conclude that TSE infectivity is likely to survive burial for long time periods with minimal loss of infectivity and limited movement from the original burial site. However PMCA results have shown that there is the potential for rainwater to elute TSE related material from soil which could lead to the contamination of a wider area. These experiments reinforce the importance of risk assessment when disposing of TSE risk materials.

 

The results show that even highly diluted PrPSc can bind efficiently to polypropylene, stainless steel, glass, wood and stone and propagate the conversion of normal prion protein. For in vivo experiments, hamsters were ic injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters, inoculated with 263K-contaminated implants of all groups, developed typical signs of prion disease, whereas control animals inoculated with non-contaminated materials did not.

 

Our data establish that meadow voles are permissive to CWD via peripheral exposure route, suggesting they could serve as an environmental reservoir for CWD. Additionally, our data are consistent with the hypothesis that at least two strains of CWD circulate in naturally-infected cervid populations and provide evidence that meadow voles are a useful tool for CWD strain typing.

 

Conclusion. CWD prions are shed in saliva and urine of infected deer as early as 3 months post infection and throughout the subsequent >1.5 year course of infection. In current work we are examining the relationship of prionemia to excretion and the impact of excreted prion binding to surfaces and particulates in the environment.

 

Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC) are shed in urine of infected deer as early as 6 months post inoculation and throughout the subsequent disease course. Further studies are in progress refining the real-time urinary prion assay sensitivity and we are examining more closely the excretion time frame, magnitude, and sample variables in relationship to inoculation route and prionemia in naturally and experimentally CWD-infected cervids.

 

Conclusions. Our results suggested that the odds of infection for CWD is likely controlled by areas that congregate deer thus increasing direct transmission (deer-to-deer interactions) or indirect transmission (deer-to-environment) by sharing or depositing infectious prion proteins in these preferred habitats. Epidemiology of CWD in the eastern U.S. is likely controlled by separate factors than found in the Midwestern and endemic areas for CWD and can assist in performing more efficient surveillance efforts for the region.

 

Conclusions. During the pre-symptomatic stage of CWD infection and throughout the course of disease deer may be shedding multiple LD50 doses per day in their saliva. CWD prion shedding through saliva and excreta may account for the unprecedented spread of this prion disease in nature.

 

see full text and more ;

 

Monday, June 23, 2014

 

*** PRION 2014 CONFERENCE CHRONIC WASTING DISEASE CWD

 


 


 

*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.

 


 

First Live Test for Chronic Wasting Disease Last Modified: Jan 30, 2014 NWRC researchers and partners recently completed their third year of evaluating and validating the first live rectal-tissue biopsy method for detecting chronic wasting disease (CWD) in captive and wild elk. To date, researchers have collected over 1,500 biopsies from captive elk in Colorado and used the technique to find 15 elk that were positive for CWD. As compared to proven post-mortem diagnostic tests, this live test appears to be nearly as accurate.

 

“The key advantage to the rectal biopsy test is that it can be performed on live animals. Until now, there was no practical live test for CWD in elk,” said NWRC's Dr. Kurt VerCauteren. “With this technique we can detect CWD in animals not showing any signs of the disease and, thus, remove them so they are not left to infect other individuals and further contaminate the environment.”

 

The research is a collaborative effort between APHIS' WS and Veterinary Services programs, the Agricultural Research Service, and the Colorado State University Veterinary Diagnostic Laboratory within the College of Veterinary Medicine and Biomedical Sciences. The majority of the research was conducted on the Velvet Ridge Elk Ranch, owned by Dennis and Stephanie White, near Fort Collins, Colorado. In 2002, an elk on the ranch was confirmed to have CWD and since that time the Whites have worked closely with NWRC and other collaborators to learn more about CWD and to develop methods to manage it in captive and wild settings.

 

“The use of this new live test in the initial screening, surveillance and monitoring of CWD will greatly aid in the management and control of the disease in the wild, as well as in captive settings,” said VerCauteren. More studies are needed before the live rectal test can be used on a large scale. For more information, please contact nwrc@aphis.usda.gov.

 


 

Monday, May 05, 2014

 

cwd tse prion testing PMCA , IHC, tonsil, rectal, biopsy ???

 


 

Thursday, July 03, 2014

 

*** How Chronic Wasting Disease is affecting deer population and what’s the risk to humans and pets?

 


 

Tuesday, July 01, 2014

 

*** CHRONIC WASTING DISEASE CWD TSE PRION DISEASE, GAME FARMS, AND POTENTIAL RISK FACTORS THERE FROM

 


 
 
Wednesday, September 17, 2014
 
Cervid Health Business Plan Fiscal Years 2014 to 2018 Animal and Plant Health Inspection Service Veterinary Services
 
 
 
 

what is the BIG SECRET about this recent case of nvCJD in Texas ???
 

Monday, June 02, 2014

 

*** Confirmed Human BSE aka mad cow Variant CJD vCJD or nvCJD Case in Texas

 


 

Tuesday, April 01, 2014

 

*** Questions linger in U.S. CJD cases 2005, and still do in 2014 ***

 


 

Sunday, March 09, 2014

 

A Creutzfeldt-Jakob Disease (CJD) Lookback Study: Assessing the Risk of Blood Borne Transmission of Classic Forms of Creutzfeldt-Jakob Disease

 

FDA TSEAC CIRCUS AND TRAVELING ROAD SHOW FOR THE TSE PRION DISEASES

 


 

Sunday, April 06, 2014

 

SPORADIC CJD and the potential for zoonotic transmission there from, either directly or indirectly via friendly fire iatrogenic mode, evidence to date

 


 

Wednesday, December 11, 2013

 

*** Detection of Infectivity in Blood of Persons with Variant and Sporadic Creutzfeldt-Jakob Disease ***

 


 

Wednesday, September 10, 2014

 

Creutzfeldt-Jakob disease (CJD) biannual update (August 2014), with updated guidance on decontamination of gastrointestinal endoscopy equipment

 

Research and analysis

 


 

Tuesday, September 16, 2014

 

mad cow scaremongers consumerfreedom.com December 20, 2003 article and a 2014 review

 


 

tss

Wednesday, August 27, 2014

Highly sensitive detection of small ruminant BSE within TSE mixes by serial Protein Misfolding Cyclic Amplification

Highly sensitive detection of small ruminant BSE within TSE mixes by serial Protein Misfolding Cyclic Amplification 

 

Kevin C. Gougha, Keith Bishopb and Ben C Maddisonb# + Author Affiliations

 

School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington, Leicestershire, UK.a ADAS UK, The University of Nottingham, Sutton Bonington, Leicestershire, UK.b

 

ABSTRACT

 

It is assumed that sheep and goats would have consumed the same BSE contaminated meat and bonemeal that was fed to cattle and which precipitated the UK BSE epidemic, which peaked more than twenty years ago. Despite intensive surveillance for cases of BSE within the small ruminant populations of the UK and EU, no instances of BSE have been detected in sheep, and in only two instances has BSE been discovered within goats. If BSE were present within the small ruminant populations it may be at subclinical levels, may manifest as scrapie or may be masked by co-infection with scrapie. To determine whether BSE is potentially circulating at low levels within the European small ruminant populations, highly sensitive assays are required that could specifically detect BSE even within the presence of scrapie prion protein. Here we present a novel assay based on the specific amplification of BSE using the serial Protein Misfolding Cyclic Amplification assay (sPMCA), which specifically amplified low amounts of ovine and caprine BSE which had been mixed into a range of scrapie positive brain homogenates. *** Detection of BSE prion protein within a large excess of classical, atypical and CH1641 scrapie isolates is demonstrated. In a blind trial this sPMCA based assay specifically amplified BSE within brain mixes with 100% specificity and 97% sensitivity when BSE is diluted into the scrapie brain homogenates at 1% v/v.

 

FOOTNOTES ↵#Address correspondence to Ben Maddison, ben.maddison@adas.co.uk Copyright © 2014, American Society for Microbiology. All Rights Reserved.

 


 

>>> *** Detection of BSE prion protein within a large excess of classical, atypical and CH1641 scrapie isolates is demonstrated.

 

now this is getting very interesting. what implications might this have on humans and other species ?

 

greetings cjd world,

 

I find this very interesting, this coexistence of different TSE prion strains from different TSE sources. this new/old study out reminds me of way back ;

 

According to Professor James Ironside of the National CJD Surveillance Unit, Miss Rimmer's case was "unique" and tests showed signs of both vCJD and new variant CJD.

 

"Our understanding of the case is not complete. It is one of the most unusual and difficult cases I have ever come across," he explained.

 

"The characteristics of the disease suffered by Miss Rimmer do not fall neatly into any category. "The investigations that we have performed so far would indicate that this case, unique as it is, has more similarities to sporadic CJD than to new variant."

 

snip...

 

Mr Hughes returned a verdict of death by natural causes and concluded that Miss Rimmer died of bronchial pneumonia caused by CJD. ...

 


 

Coexistence of multiple PrPSc types in individuals with CJD

 


 

Published online October 31, 2005

 

Coexistence of multiple PrPSc types in individuals with Creutzfeldt-Jakob disease

 

Magdalini Polymenidou, Katharina Stoeck, Markus Glatzel, Martin Vey, Anne Bellon, and Adriano Aguzzi

 

Summary Background

 

The molecular typing of sporadic Creutzfeldt-Jakob disease (CJD) is based on the size and glycoform ratio of protease-resistant prion protein (PrPSc), and on PRNP haplotype. On digestion with proteinase K, type 1 and type 2 PrPSc display unglycosylated core fragments of 21 kDa and 19 kDa, resulting from cleavage around amino acids 82 and 97, respectively.

 

Methods We generated anti-PrP monoclonal antibodies to epitopes immediately preceding the differential proteinase K cleavage sites. These antibodies, which were designated POM2 and POM12, recognise type 1, but not type 2, PrPSc.

 

Findings We studied 114 brain samples from 70 patients with sporadic CJD and three patients with variant CJD. Every patient classified as CJD type 2, and all variant CJD patients, showed POM2/POM12 reactivity in the cerebellum and other PrPSc-rich brain areas, with a typical PrPSc type 1 migration pattern.

 

Interpretation The regular coexistence of multiple PrPSc types in patients with CJD casts doubts on the validity of electrophoretic PrPSc mobilities as surrogates for prion strains, and questions the rational basis of current CJD classifications.

 

snip...

 

The above results set the existing CJD classifications into debate and introduce interesting questions about human CJD types. For example, do human prion types exist in a dynamic equilibrium in the brains of affected individuals? Do they coexist in most or even all CJD cases? Is the biochemically identified PrPSc type simply the dominant type, and not the only PrPSc species?

 


 

Published online October 31, 2005

 

what i been saying for years, that the diagnostic criteria differentiating between the nvCJD (i.e. 'the chosen ones') and the sCJD (i.e. 'the forgotten ones') has been terribly flawed from the beginning. ....

 

 Friday, October 11, 2013

 

Coexistence of Distinct Prion Types Enables Conformational Evolution of Human PrPSc by Competitive Selection

 


 

Wednesday, January 18, 2012

 

Selection of Distinct Strain Phenotypes in Mice Infected by Ovine Natural Scrapie Isolates Similar to CH1641 Experimental Scrapie

 

Journal of Neuropathology & Experimental Neurology: February 2012 - Volume 71 - Issue 2 - p 140–147

 


 

Wednesday, September 9, 2009

 

 Co-existence of scrapie prion protein types 1 and 2 in sporadic Creutzfeldt-Jakob disease: its effect on the phenotype and prion-type characteristics

 


 

-------- Original Message --------

 

Subject: Coexistence of CJD and Alzheimer's disease: An autopsy case showing typical clinical features of CJD

 

Date: Sat, 10 Apr 2004 21:01:13 –0500

 

From: "Terry S. Singeltary Sr."

 

To: Bovine Spongiform Encephalopathy

 

 Neuropathology Volume 24 Issue 1 Page 46 - March 2004 doi:10.1111/j.1440-1789.2003.00513.x

 

Coexistence of CJD and Alzheimer's disease: An autopsy case showing typical clinical features of CJD Kuniaki Tsuchiya1,2,3 , Saburo Yagishita4 , Kenji Ikeda2 , Michio Sano5 , Kazuhiro Taki6 , Keisuke Hashimoto6 , Sadakiyo Watabiki3

 

and Hidehiro Mizusawa7

 

The present report concerns an autopsy case of CJD showing typical clinical features of CJD. The patient was a Japanese woman without hereditary burden or dementing disorder anamnesis who was 70-years-old at the time of death. She developed gait disturbance at age 68, followed by memory impairment, visual disturbance, and myoclonus. A neurological examination approximately 2 months after the disease onset revealed akinetic mutism, in addition to periodic synchronous discharges on electroencephalogram. Serial neuroradiological examinations disclosed progressive atrophy of the brain. She died of bronchopneumonia 25 months after the disease onset. The brain weighed 560 g (cerebrum 490 g, brainstem with cerebellum 70 g). Macroscopically, neuropathological examination showed prominent atrophy of the cerebrum, caudate nucleus, and cerebellum, in addition to necrosis of the cerebral white matter, compatible with panencephalopathic CJD. Histologically, there was neuronal loss with or without spongiform change in the cerebral cortex, parahippocampal gyrus, amygdala, striatum, pallidum, thalamus, pontine nucleus, and cerebellar granule cells, in addition to diffuse synaptic-type prion staining in the cerebrum and cerebellum. Furthermore, senile plaques, compatible with definite Consortium to establish a registry for Alzheimer's disease rank Alzheimer's disease, and neurofibrillary changes of the limbic system, consistent with stage IV of Braak's classification, were found. Based on these clinicopathological findings and a review of the published literature, it is concluded that there were two forms of coexistence of CJD and Alzheimer's disease in the same patient.

 

Received 14 May 2003; revised and accepted 23 July 2003.

 

Affiliations

 

1Department of Laboratory Medicine and Pathology, Tokyo Metropolitan Matsuzawa Hospital, 2Department of Neuropathology, Tokyo Institute of Psychiatry, 3Department of Neurology, Musashino Red Cross Hospital, Tokyo, 4Department of Pathology, Kanagawa Rehabilitation Center, Kanagawa, 5Department of Internal Medicine, Musashisakai Hospital, 6Department of Pathology, Musashino Red Cross Hospital and 7Department of Neurology, Tokyo Medical and Dental University, Tokyo, Japan

 

Correspondence

 

Kuniaki Tsuchiya, md, PhD, Department of Laboratory Medicine and Pathology, Tokyo Metropolitan Matsuzawa Hospital, 2-1-1, Kamikitazawa, Setagaya-ku, Tokyo, 156-0057, Japan. Email: ktsuchi@jcom.home.ne.jp

 

To cite this article Tsuchiya, Kuniaki, Yagishita, Saburo, Ikeda, Kenji, Sano, Michio, Taki, Kazuhiro, Hashimoto, Keisuke, Watabiki, Sadakiyo & Mizusawa, Hidehiro (2004) Coexistence of CJD and Alzheimer's disease: An autopsy case showing typical clinical features of CJD. Neuropathology 24 (1), 46-55. doi: 10.1111/ j.1440-1789.2003.00513.x

 


 

Thursday, July 31, 2014

 

EFSA Scrapie reduction unlikely without effective breeding programme

 


 

Sunday, August 24, 2014

 

USAHA 117TH ANNUAL MEETING USDA-APHIS–VS CWD Herd Certification Program Goals TSE PRION October 17 – 23, 2013

 


 

Tuesday, August 12, 2014

 

MAD COW USDA TSE PRION COVER UP or JUST IGNORANCE, for the record AUGUST 2014

 


 

IT is of my opinion, that the OIE and the USDA et al, are the soul reason, and responsible parties, for Transmissible Spongiform Encephalopathy TSE prion diseases, including typical and atypical BSE, typical and atypical Scrapie, and all strains of CWD, and human TSE there from, spreading around the globe.

 

 

I have lost all confidence of this organization as a regulatory authority on animal disease, and consider it nothing more than a National Trading Brokerage for all strains of animal TSE, just to satisfy there commodity. AS i said before, OIE should hang up there jock strap now, since it appears they will buckle every time a country makes some political hay about trade protocol, commodities and futures. IF they are not going to be science based, they should do everyone a favor and dissolve there organization.

 

JUST because of low documented human body count with nvCJD and the long incubation periods, the lack of sound science being replaced by political and corporate science in relations with the fact that science has now linked some sporadic CJD with atypical BSE and atypical scrapie, and the very real threat of CWD being zoonosis, I believed the O.I.E. has failed terribly and again, I call for this organization to be dissolved. ...

 

 

Tuesday, July 17, 2012

 

O.I.E. BSE, CWD, SCRAPIE, TSE PRION DISEASE Final Report of the 80th General Session, 20 - 25 May 2012

 


 

 

Thursday, December 20, 2012

 

OIE GROUP RECOMMENDS THAT SCRAPE PRION DISEASE BE DELISTED AND SAME OLD BSe WITH BOVINE MAD COW DISEASE

 


 

Monday, November 30, 2009

 

*** USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE, DOES NOT SURPRISE ME $

 


 

Sunday, August 24, 2014

 

USAHA 117TH ANNUAL MEETING USDA-APHIS–VS CWD Herd Certification Program Goals TSE PRION October 17 – 23, 2013

 

SNIP...

 

REPORT OF THE COMMITTEE 344 Ewes were experimentally inoculated with brain homogenate obtained from a U.S. sheep with clinical Nor98-like scrapie.

 

Recipient ewes are bred annually to examine the placenta for evidence of a transmissible agent. Placentas shed 2009-2013 were negative.

 

*** In 2013, one recipient ewe developed an unrelated disease. At postmortem examination, abundant accumulation of PrPSc was observed only in the cerebellum of this ewe with much less accumulation in the hindbrain obex. This confirms that initial inoculation of these ewes has been successful. Monitoring continues in the remaining ewes of this study.

 

Sunday, August 24, 2014

 

USAHA 117TH ANNUAL MEETING USDA-APHIS–VS CWD Herd Certification Program Goals TSE PRION October 17 – 23, 2013

 


 

Sunday, June 29, 2014

 

Transmissible Spongiform Encephalopathy TSE Prion Disease North America 2014

 


 

 

TSS