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SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE Draft minutes of the open session of the 93rd meeting held on 6th July 2006 snip... The Chair noted that recent reports described two cases of BSE in cattle in the United States of America (USA) as being similar to atypical cases of BSE found in a number of European countries. The Chair suggested that the term "atypical BSE", used in the USA report, is potentially confusing and that this would be discussed under any other business. Dr Danny Matthews (Veterinary Laboratories Agency [VLA]) explained that data from western blots of the USA cases resembled that of a small number of atypical cases of BSE in France. A study of the French cases had shown the condition to be transmissible to mice by intracerebral (ic) inoculation with the neuropathological phenotype maintained on transmission3. Claims have been made about the existence of atypical cases of BSE in other countries but these have yet to be confirmed. No study has yet examined the tissue distribution of abnormal prion protein (PrPSc) or infectivity in such atypical cases of BSE. 3 Baron et al. (2006) Transmission of new bovine prion to mice. Emerging. Infect. Diseases. 12, 1125-1128. http://www.seac.gov.uk/minutes/draft93.pdf However, based on analysis of molecular features of prion diseases in cattle, this situation is similar to that in humans (5), in which different subtypes of sporadic Creutzfeldt- Jakob disease agents are found. DISPATCHES 1126 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 12, No. 7, July 2006 http://www.cdc.gov/ncidod/EID/vol12no07/pdfs/vol12no07.pdf Cristina Casalone *, Gianluigi Zanusso , Pierluigi Acutis *, Sergio Ferrari , Lorenzo Capucci , Fabrizio Tagliavini ¶, Salvatore Monaco ||, and Maria Caramelli * Transmissible spongiform encephalopathies (TSEs), or prion diseases, are mammalian neurodegenerative disorders characterized by a posttranslational conversion and brain accumulation of an insoluble, protease-resistant isoform (PrPSc) of the host-encoded cellular prion protein (PrPC). Human and animal TSE agents exist as different phenotypes that can be biochemically differentiated on the basis of the molecular mass of the protease-resistant PrPSc fragments and the degree of glycosylation. Epidemiological, molecular, and transmission studies strongly suggest that the single strain of agent responsible for bovine spongiform encephalopathy (BSE) has infected humans, causing variant Creutzfeldt-Jakob disease. The unprecedented biological properties of the BSE agent, which circumvents the so-called "species barrier" between cattle and humans and adapts to different mammalian species, has raised considerable concern for human health. To date, it is unknown whether more than one strain might be responsible for cattle TSE or whether the BSE agent undergoes phenotypic variation after natural transmission. Here we provide evidence of a second cattle TSE. The disorder was pathologically characterized by the presence of PrP-immunopositive amyloid plaques, as opposed to the lack of amyloid deposition in typical BSE cases, and by a different pattern of regional distribution and topology of brain PrPSc accumulation. In addition, Western blot analysis showed a PrPSc type with predominance of the low molecular mass glycoform and a protease-resistant fragment of lower molecular mass than BSE-PrPSc. Strikingly, the molecular signature of this previously undescribed bovine PrPSc was similar to that encountered in a distinct subtype of sporadic Creutzfeldt-Jakob disease. C.C. and G.Z. contributed equally to this work. ||To whom correspondence should be addressed. E-mail: salvatore.monaco@mail.univr.it. PLEASE NOTE, if spontaneous scrapie or CWD does not occur, then why is it that only BSE and sproadic CJD are capable of spontaneous mutation $$$ Science 24 September 2004: Perspectives The recent discovery of two BSE-infected cows, one in Canada and one in the United States, has dramatically increased concern in North America among meat producers and consumers alike over the extent to which BSE poses a threat to humans as well as to domestic and wild animals. The European BSE epidemic of the late-1980s seems to have been initiated a decade earlier in the United Kingdom by changes in the production of meat and bone meal (MBM) from rendered livestock, which led to contamination of MBM with the BSE infectious agent. Furthermore, the fact that UK farmers fed this rendered MBM to younger animals and that this MBM was distributed to many countries may have contributed to the ensuing BSE epidemic in the United Kingdom and internationally (2). Despite extensive knowledge about the spread of BSE through contaminated MBM, the source of BSE in Europe remains an unsolved mystery (2). It has been proposed that BSE could be derived from a cross-species infection, perhaps through contamination of MBM by scrapie-infected sheep tissues (see the figure). Alternatively, BSE may have been an endemic disease in cattle that went unnoticed because of its low level of horizontal transmission. Lastly, BSE might have originated by "spontaneous" misfolding of the normal cellular prion protein into the disease-associated abnormal isoform (3), which is postulated to be the infectious agent or "prion." Five possible sources of BSE in North American cattle. Sheep, deer, and elk could spread prion diseases (TSEs) to cattle through direct animal contact or contamination of pastures. Endemic BSE has not been proven to exist anywhere in the world, but it is difficult to exclude this possibility because of the inefficient spread of BSE infectivity between individual animals (2). BSE caused by spontaneous misfolding of the prion protein has not been proven. Spontaneous protein misfolding is not a new phenomenon as proteins are known to sometimes misfold after synthesis. Cells in turn have devised ingenious ways to deal with this problem. These include molecular chaperone proteins that bind to misfolded proteins and help them to unfold, and organelles called proteosomes that degrade misfolded or unwanted proteins. However, although misfolded prion proteins have been generated in test tubes as well as in cultured cells, it has been difficult to demonstrate that such misfolded abnormal prion proteins are infectious (4, 5). Even the most recent data do not prove conclusively that infectivity has been generated in vitro because misfolded synthetic prion proteins were not able to transfer disease directly to wild-type mice (6). To obtain infectivity and subsequent prion disease, the misfolded proteins had to be inoculated and incubated for 1 to 2 years in transgenic mice that overexpressed a mutant version of the prion protein. Previous data from this group showed that transgenic mice expressing high amounts of prion protein developed neurological disease without inoculation of misfolded prion protein (7). Thus, at the biochemical level, the critical attributes of the misfolded prion protein required for infectivity are not known, and misfolding of prion protein alone may not be sufficient to generate an infectious agent (8). Another way to look at this problem is to examine evidence for possible spontaneous TSE disease in other animals besides cattle. Spontaneous BSE would be extremely difficult to detect in cattle, where horizontal spread is minimal. However, in the case of the sheep TSE disease, scrapie, which spreads from ewes to lambs at birth as well as between adults, spontaneous disease should be detectable as new foci of clinical infection. In the early 1950s scrapie was eradicated in both Australia and New Zealand, and the mainland of both these countries has remained scrapie-free ever since. This scrapie-free status is not the result of selection of sheep resistant to scrapie because sheep from New Zealand are as susceptible as their UK counterparts to experimental scrapie infection (12). These experiments of man and nature appear to indicate that spontaneous clinical scrapie does not occur in sheep. Similarly, because CWD is known to spread horizontally, the lack of CWD in the deer or elk of eastern North America but its presence in western regions would also argue against a spontaneous disease mechanism. This is particularly noteworthy in New Zealand, where there are large numbers of deer and elk farms and yet no evidence of spontaneous CWD. If spontaneous scrapie does not occur in sheep or deer, this would suggest that spontaneous forms of BSE and sporadic Creutzfeldt-Jakob disease (sCJD) are unlikely to be found in cattle or humans. The main caveat to this notion is that spontaneous disease may arise in some animal species but not others. In humans, sCJD--which is considered by some researchers to begin by spontaneous misfolding of the prion protein--usually takes more than 50 years to appear. Thus, in animals with a shorter life-span, such as sheep, deer, and cattle, an analogous disease mechanism might not have time to develop. What can we conclude so far about BSE in North America? Is the BSE detected in two North American cows sporadic or spontaneous or both? "Sporadic" pertains to the rarity of disease occurrence. "Spontaneous" pertains to a possible mechanism of origin of the disease. These are not equivalent terms. The rarity of BSE in North America qualifies it as a sporadic disease, but this low incidence does not provide information about cause. For the two reported North American BSE cases, exposure to contaminated MBM remains the most likely culprit. However, other mechanisms are still possible, including cross-infection by sheep with scrapie or cervids with CWD, horizontal transmission from cattle with endemic BSE, and spontaneous disease in individual cattle. Based on our understanding of other TSEs, the spontaneous mechanism is probably the least likely. Thus, "idiopathic" BSE--that is, BSE of unknown etiology--might be a better term to describe the origin of this malady. What does all this imply about testing cattle for BSE in North America? Current testing in the United States indicates that BSE is rare (one positive result in 40,000 cattle tested). However, additional testing of 200,000 head of slaughtered cattle over the next 1 to 2 years, as recently proposed by the U.S. Department of Agriculture (USDA), should tell us the incidence more precisely. Nevertheless, if any rare cases are detected, we may still not know their origin. If evidence arises of a focal occurrence of BSE, we might gain important insight into unexpected sources of contamination. However, because current tests do not seem to be able to detect BSE in infected animals less than 30 months of age, even more extensive testing will not completely guarantee the negative status of younger animals in the food chain. Therefore, the alternative option of testing all slaughtered cattle, as implemented in some countries such as Japan, would appear to provide little additional benefit. This fact has been acknowledged as the basis for a new agreement between the United States and Japan aimed at reestablishing the beef trade between the two countries. One problem with the current U.S. testing program was the announcement a few months ago of unconfirmed positive BSE tests in two additional North American animals that were subsequently found to be negative when tested with the more accurate method of Western blotting. The public release of information about unconfirmed positive tests detected by the rapid test used for mass screening may be a good idea in the interest of openness, but it has the potential to create unwarranted anxiety. If unconfirmed positives are a frequent occurrence, it would seem reasonable to follow a more cautious approach and wait until confirmatory testing is complete before publicly announcing the details. Based on the experience of many European countries, the mainstays of controlling BSE in cattle and avoiding spread to humans are threefold: first, eliminate feeding of ruminant tissues to ruminants; second, remove high-risk cattle tissues from human food; and third, continue to test for BSE in cattle in order to monitor progress with the elimination of the disease on a local and national basis. In the next 12 months, after extensive USDA test results are available, the extent of any possible BSE spread in the United States will be better documented. But, in fact, the United States and Canada have already instituted the most important steps to prevent the spread of cattle BSE in advance of the results--that is, a ban on feeding ruminant MBM to other ruminants and removal of high-risk tissues from meat for human consumption. It is hoped that the new data will not deviate enough from previous predictions to require further measures for management of this problem. The most important line of defense against any possible spread of BSE will be to maintain strict vigilance in the implementation of the current regulations. References US atypical BSE – further details As reported in the last BSE Report (Which? BSE May 2006) French research findings concerning the two most recent cases of BSE in the USA suggest that these cases were not typical of BSE in cattle and may reflect a sporadic form of the disease. I n the two US cases, discovered in herds in Texas and Alabama, threre was an absence of telltale spongy lesions caused by prions. In addition, the prions in brain tissue samples from these cows seemed to be distributed differently from the classic form. Laboratory studies on mice in France showed that both the classic and atypical strains could be spread from one animal to another, but the atypical strain might happen spontaneously in cattle. The Texas and Alabama cows were older animals, as were some of the other animals in Europe with seemingly atypical forms of BSE.31 Linda Detwiler, a former Agriculture Department veterinarian who consults for major food companies, cautioned against making that assumption. "I think it's kind of early to say that would be the case," Detwiler said. Other theories, she said, suggest the atypical strain might come from a mutation of BSE or even from a related disease in sheep. The US Agriculture Department has stated that whatever the cause there is no reason to change federal testing or control measures. "It's most important right now, till the science tells us otherwise, that we treat this as BSE regardless," the department's chief veterinarian, John Clifford, said in an interview. ... http://www.which.co.uk/files/application/pdf/bserep0606-445-89308.pdf BSE, BOVINE - USA: ATYPICAL STRAIN (02) [1] A USDA spokesman acknowledged Friday [2 Jun 2006] that positive BSE tests BSE, scientifically known as bovine spongiform encephalopathy and commonly USDA officials have declined in the past to provide such details, but Scientists from around the world are trying to quantify the significance of In an e-mail, a USDA spokesman said the cases raise "many unanswered The USDA spokesperson said nothing in the test results of the 2 cattle -- ****** Speaking last weekend at an international conference on prion diseases in The strain differs from BSE in that it has a longer incubation time and is The new strain also demonstrates different characteristics from BSE in Marion Simmons of the Veterinary Laboratory Agency at Weybridge urged -- [It has long been debated whether this atypical form is sporadic or whether [see also: Updated July 18, 2006 CRS REPORT FOR CONGRESS BSE (“Mad Cow Disease”): A Brief Overview Geoffrey S. Becker Specialist in Agricultural Policy Resources, Science, and Industry Division snip... 1 This report, which replaces CRS Issue Brief IB10127, Mad Cow Disease: Agricultural Issues for Congress, summarizes and updates information in other CRS reports, listed on page 6. Sources for facts and citation to reports and studies can be found in these CRS reports. Congressional Research Service ˜ The Library of Congress CRS Report for Congress Received through the CRS Web Order Code RS22345 Updated July 18, 2006 BSE (“Mad Cow Disease”): A Brief Overview Geoffrey S. Becker Specialist in Agricultural Policy Resources, Science, and Industry Division Summary The appearance of BSE (bovine spongiform encephalopathy or “mad cow disease”) in North America in 2003 raised meat safety concerns and disrupted trade for cattle and beef producers. A major issue for Congress has been how to rebuild foreign confidence in the safety of U.S. beef and regain lost markets like Japan and Korea. Among other issues are whether additional measures are needed to further protect the public and cattle herd, and concerns over the relative costs and benefits of such measures for consumers, taxpayers and industry. This report will be updated if significant developments ensue.1 What Is BSE? BSE (bovine spongiform encephalopathy or “mad cow disease”) is a fatal neurological disease of cattle, believed to be transmitted mainly by feeding infected cattle parts back to cattle. More than 187,000 cases have been reported worldwide, 183,000 of them in the United Kingdom (UK) where BSE was first identified in 1986. The annual number of new cases has declined steeply since 1992. Humans who eat contaminated beef are believed susceptible to a rare but fatal brain wasting disease, variant Creutzfeldt- Jakob disease (vCJD). About 160 people, most in the UK, have been diagnosed with vCJD since 1986, but none has been linked to any Canadian or U.S. meat consumption. BSE in North America BSE has been reported in 11 North American cattle, 10 born here and one imported from the UK. The first native case was an Alberta, Canada, beef cow reported in May 2003. Canada has since reported six more cases, most recently in July 2006 in a 50- month-old dairy cow in Manitoba. The first U.S. case was in a Canadian-born dairy cow found in Washington state in December 2003. The other two U.S. cases were a 12-yearold Texas-born and -raised beef cow, found in November 2004 but not confirmed until June 2005, and a 10-year-old Alabama beef cow found in late February 2006. CRS-2 In epidemiological investigations of the three U.S. cases, the U.S. Department of Agriculture (USDA) was unable to track down all related animals of interest, but those that were located tested negative for the disease. Despite a beef recall, some meat from the first U.S. BSE cow may have been consumed, USDA said, adding, however, that the highest-risk tissues never entered the food supply. No materials from the other two U.S. cows entered the food supply, USDA also said. In the recent Alabama case, authorities were unable to determine the cow’s herd of origin. Animal health officials initially indicated that all of the North American cases were caused by the consumption of BSEcontaminated feed. However, USDA reportedly now believes that the two native-born U.S. cattle had “atypical” BSE, which differs from other cases. If these cases are determined to be “spontaneous,” that may affect future control strategies. snip... http://ncseonline.org/NLE/CRSreports/06Jul/RS22345.pdf Research Project: Study of Atypical Bse Location: Virus and Prion Diseases of Livestock Project Number: 3625-32000-073-07 Start Date: Sep 15, 2004 Objective: Approach: Location: Virus and Prion Diseases of Livestock 2005 Annual Report Location: Virus and Prion Diseases of Livestock Title: Where We've Been and Where We're Going with Bse Testing in the United Authors Submitted to: American Association of Veterinary Laboratory Diagnosticians Technical Abstract: A review of the laboratory aspects of the United States http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=183829 http://www.fsis.usda.gov/OPPDE/Comments/03-025IFA/03-025IFA-2.pdf 3.57 The experiment which might have determined whether BSE and scrapie were http://www.bseinquiry.gov.uk/ The findings of the initial transmission, though not of the clinical or http://www.bseinquiry.gov.uk/ The results were not published at this point, since the attempted 3.58 There are several possible reasons why the experiment was not performed REPORT OF THE COMMITTEE ON SCRAPIE Chair: Dr. Jim Logan, Cheyenne, WY Vice Chair: Dr. Joe D. Ross, Sonora, TX Dr. Deborah L. Brennan, MS; Dr. Beth Carlson, ND; Dr. John R. Clifford, DC; Dr. Thomas F. Conner, OH; Dr. Walter E. Cook, WY; Dr. Wayne E. Cunningham, CO; Dr. Jerry W. Diemer, TX; Dr. Anita J. Edmondson, CA; Dr. Dee Ellis, TX; Dr. Lisa A. Ferguson, MD; Dr. Keith R. Forbes, NY; Dr. R. David Glauer, OH; Dr. James R. Grady, CO; Dr. William L. Hartmann, MN; Dr. Carolyn Inch, CAN; Dr. Susan J. Keller, ND; Dr. Allen M. Knowles, TN; Dr. Thomas F. Linfield, MT; Dr. Michael R. Marshall, UT; Dr. Cheryl A. Miller, In; Dr. Brian V. Noland, CO; Dr. Charles Palmer, CA; Dr. Kristine R. Petrini, MN; Mr. Stan Potratz, IA; Mr. Paul E. Rodgers, CO; Dr. Joan D. Rowe, CA; Dr. Pamela L. Smith, IA; Dr. Diane L. Sutton, MD; Dr. Lynn Anne Tesar, SD; Dr. Delwin D. Wilmot, NE; Dr. Nora E. Wineland, CO; Dr. Cindy B. Wolf, MN. The Committee met on November 9, 2005, from 8:00am until 11:55am, Hershey Lodge and Convention Center, Hershey, Pennsylvania. The meeting was called to order by Dr. Jim Logan, chair, with vice chairman Dr. Joe D. Ross attending. There were 74 people in attendance. The Scrapie Program Update was provided by Dr. Diane Sutton, National Scrapie Program Coordinator, United States Department of Agriculture (USDA), Animal and Plant Health Inspection Services (APHIS), Veterinary Services (VS). The complete text of the Status Report is included in these Proceedings. Dr. Patricia Meinhardt, USDA-APHIS-VS-National Veterinary Services Laboratory (NVSL) gave the Update on Genotyping Labs and Discrepancies in Results. NVSL conducts investigations into discrepancies on genotype testing results associated with the Scrapie Eradication Program. It is the policy of the Program to conduct a second genotype test at a second laboratory on certain individual animals. Occasionally, there are discrepancies in those results. The NVSL conducts follow-up on these situations through additional testing on additional samples from the field and archive samples from the testing laboratories. For the period of time from January 1, 2005, until October 15, 2005, there were 23 instances of discrepancies in results from 35 flocks. Of those 23 instances, 14 were caused by laboratory error (paperwork or sample mix-up), 3 results from field error, 5 were not completely resolved, and 1 originated from the use of a non-approved laboratory for the first test. As a result of inconsistencies, one laboratory’s certification was revoked by APHIS-VS. snip... Infected and Source Flocks As of September 30, 2005, there were 105 scrapie infected and source flocks. There were a total of 165** new infected and source flocks reported for FY 2005. The total infected and source flocks that have been released in FY 2005 was 128. The ratio of infected and source flocks cleaned up or placed on clean up plans vs. new infected and source flocks discovered in FY 2005 was 1.03 : 1*. In addition 622 scrapie cases were confirmed and reported by the National Veterinary Services Laboratories (NVSL) in FY 2005, of which 130 were RSSS cases. Fifteen cases of scrapie in goats have been reported since 1990. The last goat case was reported in May 2005. Approximately 5,626 animals were indemnified comprised of 49% non-registered sheep, 45% registered sheep, 1.4% non-registered goats and 4.6% registered goats. Regulatory Scrapie Slaughter Surveillance (RSSS) RSSS was designed to utilize the findings of the Center for Epidemiology and Animal Health (CEAH) Scrapie: Ovine Slaughter Surveillance (SOSS) study. The results of SOSS can be found at http://www.aphis.usda.gov/vs/ceah/cahm/Sheep/sheep.htm . RSSS started April 1, 2003. It is a targeted slaughter surveillance program which is designed to identify infected flocks for clean-up. During FY 2005 collections increased by 32% overall and by 90% for black and mottled faced sheep improving overall program effectiveness and efficiency as demonstrated by the 26% decrease in percent positive black faced sheep compared to FY 2004. Samples have been collected from 62,864 sheep since April 1, 2003, of which results have been reported for 59,105 of which 209 were confirmed positive. During FY 2005, 33,137 samples were collected from 81 plants. There have been 130 NVSL confirmed positive cases (30 collected in FY 2004 and confirmed in FY 2005 and 100 collected and confirmed in FY 2005) in FY 2005. Face colors of these positives were 114 black, 14 mottled, 1 white and 1 unknown. The percent positive by face color is shown in the chart below. Scrapie Testing In FY 2005, 35,845 animals have been tested for scrapie: 30,192 RSSS; 4,742 regulatory field cases; 772 regulatory third eyelid biopsies; 10 third eyelid validations; and 129 necropsy validations (chart 9). Animal ID As of October 04, 2005, 103,580 sheep and goat premises have been assigned identification numbers in the Scrapie National Generic Database. Official eartags have been issued to 73,807 of these premises. *This number based on an adjusted 12 month interval to accommodate the 60 day period for setting up flock plans. Published online before print October 20, 2005 Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0502296102 A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes ( sheep prion | transgenic mice ) Annick Le Dur *, Vincent Béringue *, Olivier Andréoletti , Fabienne Reine *, Thanh Lan Laï *, Thierry Baron , Bjørn Bratberg ¶, Jean-Luc Vilotte ||, Pierre Sarradin **, Sylvie L. Benestad ¶, and Hubert Laude * Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health. Author contributions: H.L. designed research; A.L.D., V.B., O.A., F.R., T.L.L., J.-L.V., and H.L. performed research; T.B., B.B., P.S., and S.L.B. contributed new reagents/analytic tools; V.B., O.A., and H.L. analyzed data; and H.L. wrote the paper. A.L.D. and V.B. contributed equally to this work. To whom correspondence should be addressed. Hubert Laude, E-mail: laude@jouy.inra.fr www.pnas.org/cgi/doi/10.1073/pnas.0502296102 12/10/76 snip... A The Present Position with respect to Scrapie Scrapie is a natural disease of sheep and goats. It is a slow The field problem has been reviewed by a MAFF working group It is clear that scrapie in sheep is important commercially and Recently the question has again been brought up as to whether Whether true or not. the hypothesis that these agents might be snip... 76/10.12/4.6 http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf Subject: SCRAPIE and CWD USA UPDATE July 19, 2006 As of May 31, 2006, there were 93 scrapie infected and source flocks (Figure 3). There were 12 new infected and source flocks reported in May (Figure 4) with a total of 67 flocks reported for FY 2006 (Figure 5). The total infected and source flocks that have been released in FY 2006 are 53 (Figure 6), with 7 flocks released in May. The ratio of infected and source flocks released to newly infected and source flocks for FY 2006 = 0.79 : 1. In addition, as of May 31, 2006, 216 scrapie cases have been confirmed and reported by the National Veterinary Services Laboratories (NVSL), of which 33 were RSSS cases (Figure 7). This includes 33 newly confirmed cases in May 2006 (Figure 8). Eighteen cases of scrapie in goats have been reported since 1990 (Figure 9). The last goat case was reported in March 2006. New infected flocks, source flocks, and flocks released for FY 2006 are depicted in Chart 3. New infected and source statuses from 1997 to 2006 are depicted in Chart 4. snip... Scrapie Testing In FY 2006, 26,185 animals have been tested for scrapie : 22,634 RSSS*; 2063 regulatory field cases; 61 necropsy validations, 5 rectal biopsy and 1427 regulatory third eyelid biopsies (Chart 9). ... snip...END http://www.aphis.usda.gov/vs/nahps/scrapie/monthly_report/monthly-report.html TSS
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