Wednesday, November 28, 2012

Scientific and technical assistance on the provisional results of the study on genetic resistance to Classical scrapie in goats in Cyprus 1

SCIENTIFIC REPORT OF EFSA


Scientific and technical assistance on the provisional results of the study on genetic resistance to Classical scrapie in goats in Cyprus1


European Food Safety Authority2, 3


European Food Safety Authority (EFSA), Parma, Italy


ABSTRACT


This EFSA Scientific Report reviews and discusses the provisional results of a study (EURL/Cypriot study) on genetic resistance to Classical scrapie in goats in Cyprus. It is concluded that the provisional results obtained in the study further support the lower susceptibility to Classical scrapie in goats carrying the D146 and S146 alleles compared to wild type (N146N) goats. The results from intracerebral challenge are not compatible with a level of resistance as high as the one observed in sheep carrying the ARR allele or in goats carrying the K222 allele. Final results from the oral challenge will be crucial in determining the level of resistance associated with the D146 and S146 alleles. Furthermore, it is concluded that the provisional results obtained in the study are compatible with the possibility to use the D146 and S146 alleles to build a genetic strategy to control and eradicate Classical scrapie in goats in Cyprus. However, the success of such a strategy will be determined by the level of resistance associated with the D146 and S146 alleles against infection with all the different TSE agents proved to be circulating in Cyprus, which at this stage of the EURL/Cypriot study remains to be definitively assessed. In addition, as compared to the results of the model developed in the study, it is concluded that the efficiency of the implementation in the field of a breeding strategy selecting for the D146 and S146 alleles may be lower due to potential practical constraints related to the management of genetic diversity, to the selection for production and health traits and to the need of moving animals for breeding purposes in Cyprus. Recommendations on aspects that may be considered when completing the study are formulated.


© European Food Safety Authority, 2012


KEY WORDS


TSE, Classical scrapie, goat, genetic resistance, breeding programme, Cyprus.


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Interim Conclusions


The oral challenge studies, the management cull and the whole herd cull data all support the previously published field observations that on one side the genotype N146N is particularly associated with scrapie susceptibility and on the other side the genotypes N146D, N146S, D146D, D146S and S146S are associated with a degree of resistance.


All genotypes can succumb to challenge by the intracerebral route, but the resulting phenotype is different when comparing the animals carrying genotype N146N with all the others (most notably, no detection of PrPSc in the periphery of infected animals with all the non-N146N-genotypes).


It is important that the oral challenges are continued to endpoint to establish the relative resistance of other genotypes to challenge by this more natural route Appendix A to Scientific Report of EFSA, EFSA Journal 2012;10(11):2972


Cyprus/EURL resistance in goats protocol Report May 2012


Page 13 of 13


All components of the study reinforce previously published UK caprine data3 which indicates that the current ELISA rapid test screen has considerably lower sensitivity (approx 50%) than immunohistochemistry.


The wider issue of discriminatory testing for BSE vs scrapie may need to be reviewed (regardless of genotype), since data from these studies suggest that direct extrapolation from ovine data may not be appropriate for all caprine isolates.


The TSE European Union Reference Laboratory at the Animal Health and Veterinary Laboratory Agency New Haw, UK


The Government Veterinary Services, Cyprus


May 2012







Wednesday, January 18, 2012


BSE IN GOATS CAN BE MISTAKEN FOR SCRAPIE


February 1, 2012



posted January 18, 2012



BSE in goats can be mistaken for scrapie



Bovine spongiform encephalopathy in goats could be misdiagnosed as scrapie in the absence of appropriate discriminatory tests, and such misidentification occurred at least once before such tests were developed, according to a report released in December.



The article, "Isolation of prion with BSE properties from farmed goat" (Emerging Infectious Diseases 2011;17:2253-2261), indicates BSE can affect small ruminants under natural conditions and that the condition can be misdiagnosed. The agent that causes scrapie is not known to infect humans, but consumption of beef contaminated with the prions that cause BSE is connected with variant Creutzfeldt-Jakob disease, a neurodegenerative disorder in humans.



The report calls for continued extensive surveillance and breeding plans to prevent BSE outbreaks among small ruminants. Such outbreaks could harm public health.



The authors stated in the text that the misdiagnosis occurred in 1990 in the United Kingdom. The case had been identified as suspected BSE in 2006 because differential immunohistochemical analysis of fixed brain tissue produced a signature indistinguishable from BSE. The authors of the recent report used a bioassay to confirm the BSE diagnosis.



The sample collected in 1990 was among 26 historic samples collected from 1984-2002, the report states.



The report indicates the U.K. goat and a goat in France found to have BSE in 2005 both likely became infected through contaminated food supplements.



While BSE lesions are contained mainly within nervous tissue in cattle, the report states "in small ruminants the BSE agent is widely distributed in peripheral tissues and can be transmitted horizontally." Feed ban measures alone would be insufficient for controlling a BSE outbreak in small ruminants, according to the report.



"Also, it would be impossible to prevent BSE from entering the human food chain through consumption of food products derived from small ruminants," the report states.













Discussion




We confirmed that the agent responsible for TSE in a UK goat, which was initially reported as scrapie in 1990 and subsequently as suspected BSE in 2006 (16), was a BSE agent. This conclusion was based on bioassay of nervous tissue in mice demonstrating similarities of histopathologic lesions, PrPSc mapping in the brain, and WB of PrPSc with those of mice inoculated with BSE from various ovine, caprine, and bovine sources.











Saturday, December 3, 2011




Isolation of Prion with BSE Properties from Farmed Goat Volume 17, Number




12—December 2011









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Scientific Opinion on genetic TSE resistance in goats in all European Union Member States Question number: EFSA-Q-2009-00448


Adopted: 21 October 2009 Summary (0.1Mb)


Opinion (0.3Mb)


Summary


Following a request from the European Commission, the Panel on Biological Hazards (BIOHAZ) was asked to deliver a scientific opinion on genetic resistance to Transmissible Spongiform Encephalopathies (TSE) in goats.


For a first part of that request, the BIOHAZ Panel adopted on 5th March 2009 a scientific opinion on the scientific validity of a study carried out by the Cypriot authorities under the auspices of the Community Reference Laboratory (CRL) for TSEs. That scientific opinion also indicated to what extent the information contained in the study could be used as relevant tools to control Classical scrapie in Cyprus.


In the current scientific opinion the BIOHAZ Panel addresses genetic resistance as a relevant tool for breeding for resistance to all TSEs of goats (including Atypical scrapie and BSE) in all the Member States (MSs) (except for Classical scrapie in Cyprus).


To carry out this task, available scientific knowledge on genetic TSE resistance in goats in the EU is reviewed, addressing those PRNP polymorphisms for which a capacity to provide resistance to TSEs in goats has been (or is being) investigated. Details tailored to the different TSEs found in this small ruminants (i.e. Classical scrapie, Atypical scrapie and BSE) are also considered and presented.


Further on, the feasibility of a large-scale breeding program in animal populations would need to be supported by a sound logistical and technical infrastructure in any given territory. In order to collect preliminary data that could help to evaluate the specific situation in the different EU MSs, a questionnaire was developed and circulated among the EFSA BSE-TSE Network. The results of the analysis of the replies received are also presented herewith.


The BIOHAZ Panel concluded that there are encouraging but as yet incomplete data to consider supporting a breeding programme for resistance in goats against Classical scrapie in all EU MSs, and ongoing studies are expected to provide a more robust scientific background in the coming years. On the other hand, at this moment there are not enough data available to consider supporting a breeding programme for resistance against Atypical scrapie and BSE in goats in all EU MSs. Experiments are ongoing on BSE in goats and results will be available in the next years. Furthermore, there are limited data suggesting that an allele (H154) might confer resistance to Classical scrapie but increase susceptibility to Atypical scrapie.


The frequency of the wild type allele, which is known to confer susceptibility to Classical scrapie, is high in all goat breeds considered. Thus, selection for putative resistance alleles will be slow, complicated and highly dependent on breeding structure.


It is acknowledged that any large scale breeding programme for TSE resistance in goats must take into consideration key elements related to the current dissemination of potentially TSE protective polymorphisms in the goat population of each EU MS and the characterisation of the real protection provided by those polymorphisms. At present, only a few EU MSs seem to have in place the necessary elements to introduce a breeding for resistance programme for Classical scrapie in goats.


The BIOHAZ Panel makes a series of recommendations on new investigations in order to assess the efficacy of breeding for the candidate PRNP alleles as a mean to control TSEs in goats. Furthermore, research on the possible adverse effects of the candidate PRNP polymorphisms on other production traits should be encouraged. In addition, it is recommended that a breeding for resistance programme for TSE in goats is first implemented in the seven EU MSs with the largest goat population as this would have the most impact.


Published: 9 November 2009







OPINION








Tuesday, November 10, 2009


A retrospective immunohistochemical study reveals atypical scrapie has existed in the United Kingdom since at least 1987


Brief Research Reports








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


Subject: Twelve Greek goats were found to be suffering from the brain-wasting disease scrapie in the first half of 2004


Date: Wed, 19 Jan 2005 13:30:26 –0600


From: "Terry S. Singeltary Sr."


To: Bovine Spongiform Encephalopathy


CC: cjdvoice@yahoogroups.com


Wednesday January 19, 2005


Brain disease in Greek goats


Twelve Greek goats were found to be suffering from the brain-wasting disease scrapie in the first half of 2004, EU figures made public yesterday reveal.


The data, issued by the European Food Safety Authority (EFSA), show that 12 cases of transmissible spongiform encephalopathies (TSE) were discovered in Greece, eight in Cyprus and 26 in France out of some 17,294 goats tested throughout the EU in 2004. The figures were made public by Left Coalition Synaspismos MEP Dimitris Papadopoulos.


Some 100 Europeans have died from the human form of bovine spongiform encephalopathy (BSE), or mad cow disease, a strain of the TSE group. Meanwhile, tests are continuing in the case of a French goat slaughtered in 2002, which experts think may have developed BSE. The EU bans the use of milk and meat from herds affected by a TSE case.









TSS





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


Subject: Twelve Greek goats were found to be suffering from the brain-wasting disease scrapie in the first half of 2004


Date: Wed, 19 Jan 2005 13:30:26 –0600


From: "Terry S. Singeltary Sr."


To: Bovine Spongiform Encephalopathy


CC: cjdvoice@yahoogroups.com


Wednesday January 19, 2005


Brain disease in Greek goats


Twelve Greek goats were found to be suffering from the brain-wasting disease scrapie in the first half of 2004, EU figures made public yesterday reveal.


The data, issued by the European Food Safety Authority (EFSA), show that 12 cases of transmissible spongiform encephalopathies (TSE) were discovered in Greece, eight in Cyprus and 26 in France out of some 17,294 goats tested throughout the EU in 2004. The figures were made public by Left Coalition Synaspismos MEP Dimitris Papadopoulos.


Some 100 Europeans have died from the human form of bovine spongiform encephalopathy (BSE), or mad cow disease, a strain of the TSE group. Meanwhile, tests are continuing in the case of a French goat slaughtered in 2002, which experts think may have developed BSE. The EU bans the use of milk and meat from herds affected by a TSE case.










TSS





Comment from Terry S Singeltary, CJD WATCH/VOICE




Document ID: APHIS-2007-0033-0002 Document Type: Public Submission
This is comment on Proposed Rule: Agricultural Bioterrorism Protection Act of 2002; Biennial Review and Republication of the Select Agent and Toxin List
Docket ID:
RIN:0579-AC53

Topics: No Topics associated with this document

View Document:





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Under APHIS-PPQ’s agriculture quarantine inspection monitoring, 584 air passengers from Greece were sampled for items of agricultural interest in fiscal year 2000. Of these passengers, 14 carried meat (non-pork) items that could potentially transmit pathogens that cause BSE; most passengers carried from one to two kilograms (kg) of meat, although one passenger in November 1999 carried 23 kg of meat in a suitcase. Florida, Massachusetts, and New York were the reported destinations of these passengers. None of the passengers with meat items reported plans to visit or work on a ranch or farm while in the US.





Source: US Department of Transportation, and APHIS-PPQ Agricultural Quarantine Inspection data base

















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