SCRAPIE: ERADICATE IT
The sheep industry's scrapie eradication efforts. American Sheep
Industry Association
The goal of the American Sheep Industry Association (ASI) and the U.S. sheep industry is to eradicate scrapie from our borders by 2010. In addition, it is the objective to have the World Organization for Animal Health, OIE, declare the United States scrapie free by 2017. This quarterly publication is created specifically for those of you in the field who are also working to achieve this goal.
This newsletter brings together, into one spot, current information from all 50 states, as well as from the U.S. Department of Agriculture and any other organization providing scrapie news, and reports it back to the field.
If you have first-hand accounts that you believe would be relevant for others to read or have information that you would like included in this newsletter, please let us know at becky@sheepusa.org.
March 2008
Nor98-Like Scrapie Found in the United States
By BECKY TALLEY
Sheep Industry News Associate Editor
In February of last year, the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) officially announced the discovery of a Nor98-like scrapie case in a ewe from a flock in Wyoming. This was the first case of scrapie consistent with Nor98 discovered in the United States. Since then, four more cases have been discovered that originated from flocks in Colorado, Indiana, Minnesota and California. These cases are not related to either the first one in Wyoming or to each other. This scrapie type was first found in Norway in 1998 and has since been found in sheep and goats in many countries in Europe.
“It does affect goats,” says Diane Sutton, DVM, national scrapie coordinator for USDA. “So far not here in the United States, but chances are, we might eventually see it in goats here too.” This type of scrapie affects sheep of all commonly occurring genotypes including those that are resistant to classical scrapie.
According to Sutton, those flocks in the United States that are found to be infected with Nor98-like scrapie will not be able to use the current genetic-base approach to flock clean up. Producers whose flocks have risk factors for classical scrapie are still encouraged to test at codon 171 for classical scrapie resistance, as has been done in the past.
The World Organization for Animal Health (OIE) has formed an ad hoc committee to consider how to address Nor98-like scrapie with respect to trade. It will likely be at least two years before a code change could be made should a consensus be reached.
“Until research provides us with other options for eliminating Nor98-like scrapie and the international community reaches a consensus on guidelines for trade we will continue to use flock depopulation and exposure-based clean up plans for Nor98-like scrapie affected flocks,” says Sutton. “As other viable options are identified, we will evaluate them using pilot projects.”
According to Linda Detwiler, DVM, assistant director, Center for Public and Corporate Veterinary Medicine, it is important to note that it isn’t known if the appearance of non-classical scrapie cases in Europe and the United States are more likely due to the increased ability to test for and detect non-classical scrapie than to increasing rates of infection. Scientists in European countries are beginning to look at archived samples in an attempt to identify non-classical cases that may have occurred earlier than 1998. “I would caution everyone that it’s premature to be able to say much of anything about these non- classical cases. At this point in time, there are many unknowns such as: 1) is there more than one strain, 2) what is the origin, 3) are there natural modes of transmission, 4) does the genotype affect incubation time and clinical presentation, 5) do codons other than 136, 141, 154 and 171 influence these cases and 6) how long have these cases been occurring?” she questions.
Because of Europe’s increased awareness of non-classical scrapie, there has been quite a bit of research into understanding how and if the disease is transmitted and how it affects sheep. Research is currently underway in the United States.
“The first U.S. material became available in February, so ARS (Agricultural Research Service) is gearing up to study it. But, because of the nature and long-term aspects of the disease, it will take a while to study, so we will probably be seeing research from Europe published first,” Sutton adds.
In the meantime, it is stressed that officials will continue to handle the disease as it has in the past, and that producers should be aware of Nor98-like scrapie but not alarmed.
“We are going to treat it as scrapie until the international community removes it as a trade barrier or science finds that there is a better way to handle it than the current system,” Sutton says.
Jim Logan’s, DVM, chair of ASI’s Animal Health Committee, best advice to producers to protect their flock from Nor98-like scrapie is to maintain a closed ewe flock. He says that to prevent the introduction of all scrapie types, producers need to be aware of where new purchases are coming from, know the genetics of new purchases and avoid purchasing ewes unless familiar with the scrapie status of the farm of origin or maintain a closed ewe flock.
“Essentially, people need to use common sense and maintain good sanitation and husbandry practices,” he explains.
Nor98 is a relatively common prion disease or transmissible spongiform encephalopathy of sheep. The first descriptions of the disorder were in sheep diagnosed in 1998 in Norway, although a retrospective study has revealed a case in England in 1989. Improved methods for diagnostic testing were published in 2002 and surveillance was initiated in many European countries. Most cases are identified in clinically normal sheep tested in routine slaughter surveillance. The disease is experimentally transmissible to sheep and genetically altered mice by inoculation into their brains but no data are yet available on whether the disease is transmitted between sheep in an affected flock.
Clinical Signs
Most cases have been discovered in clinically normal sheep tested at slaughter. Of the few clinical cases, a common sign is progressive incoordination (ataxia), occurring most likely because the abnormal prions accumulate in the cerebellum, the region of the brain (the cerebellum) that integrates information coming in from the senses with nerve impulses going to the muscles.
Diagnosis
Both classical scrapie and Nor98-like scrapie are characterized by accumulation of abnormal prion proteins. However, the distribution of the prion proteins differ. In classical scrapie, prions are usually found earliest in the lymph nodes and later in the region of the brain associated with innervation of the gut. As discussed above, abnormal prions are found in different areas of the brain in cases of Nor98. Further, prion proteins are not found in the lymph nodes of sheep with Nor98 and the current live animal tests of lymphoid tissues are not suitable. Nor98 is a challenging diagnosis but skilled pathologists, working with a panel of three different diagnostic tests, can accurately diagnose the disease in the brain of affected sheep.
Genetics
Susceptibility to classical scrapie is associated with naturally occurring differences in the gene for the prion protein, particularly differences at position 136 and 171. Each sheep has two copies of this gene and commercially available genotype tests show the differences at those positions. Sheep with the genotypes 136VV 171QQ and 136AV 171QQ are very susceptible to classical scrapie strains. Sheep with the 136AA 171QQ genotype are susceptible to the most common classical scrapie strain in the United States and represent the most common genotype found in U.S. scrapie cases. Sheep with at least one copy of the gene 136A 171R are generally resistant to the more common type of classical scrapie. Although no genotype is considered to be resistant to Nor98-like scrapie, the disorder is found most frequently in sheep with changes in positions 141 and/or 154. The genetic signature AFRQ indicates a sheep with 136A and 171Q with the additional change to “F” at 141. The signature AHQ indicates a sheep with 136A and 171Q with a change to “H” at position 154. A large survey of 4,000 sheep in Europe and numerous reports on smaller study populations has demonstrated that sheep with either the AFRQ or the AHQ gene were eight to 15 times more likely to be diagnosed with Nor98-like scrapie than were sheep with the most common genotype ARQ. Sheep with both changes were more than 20 times more likely to be diagnosed with Nor98-like scrapie. Sheep with the 171R form of the gene are generally resistant to classical scrapie but are susceptible to Nor98-like scrapie, particularly in 171QR sheep that have an AFRQ gene.
Epidemiology
Classical scrapie is usually found in more than one sheep in a flock, with prevalence as high as 30 percent with some scrapie strains. In contrast, more than one sheep with Nor98-like scrapie is usually found
The Science Behind Nor98 in Sheep
only in flocks of more than 500 sheep. In addition to genotype, age appears to represent a significant risk factor for Nor98-like scrapie. In the large European study, 80 percent of the cases of classical scrapie were found in sheep ages 3-5, a finding similar to that reported in the US. In contrast, more than 60 percent of the sheep with Nor98-like scrapie were older than five years and more than 25 percent were more than 10 years old. Nor98 is found in most countries performing large-scale surveillance; the disorder occurs at a rate of approximately one in 1,400 mature sheep at slaughter even if the rate of classical scrapie is very low.
The low prevalence of Nor98 within flocks, the wide geographic distribution of the disorder, the range in age of onset or diagnosis, and the genetic factors increasing the risk of Nor98 are strikingly different than those found in classical scrapie. There may be additional genetic factors influencing development of this disorder, in addition to factors such as route of infection or age at which sheep are infected. Alternatively, Nor98 may be a sporadic disease of sheep, appearing primarily but not exclusively in older sheep. Additional findings from experimental studies and large scale surveillance using improved diagnostic methods will be useful in understanding this wide-spread prion disease of sheep.
Background Information
Luhken and others, 2007, Veterinary Research 38: 65-80. Bruce and others, 2007, Veterinary Record 160: 665-666. Benestad and others, 2003, Veterinary Record 153: 202-208. Animals Sampled for Scrapie Testing
Sheep and Goats
19,667 animals have been sampled for scrapie testing: 16, 710 RSSS; 1,474 goats for the CSPS study; 1,224 regulatory field cases; 227 regulatory third eyelid biopsies; and 32 regulatory rectal biopsies. Testing of lympoid tissue obtained by rectal bopsy was approved by USDA as an official live-animal test on Jan. 11, 2008.
As of February 29, 2008
Infected and Source Flocks New Statuses by Year
FY 1997 – 2008* *Through February 29, 2008 Scrapie Confirmed Cases in 2008 Scrapie Flock Certification Program Participating Flocks SFCP Flocks Enrolled and Certified in February 2008 Through February 29, 2008 Total Enrolled Flocks—2,043 Complete Monitored—1,599 Certified—435 Export Monitored—5 Elective Monitored—4 Slaughter Surveillance Samples Collected by Month, FY 2004 to FY 2008* The Animal and Plant Health Inspection Service's goal is to collect 4,000 slaughter surveillance samples each month from around the United States. Regulatory Scrapie Slaughter Surveillance (RSSS) Statistics through February 29, 2008 *National Veterinary Services Laboratories Web Sites Dedicated to the Eradication of Scrapie Animal and Plant Health Inspection Service www.aphis.usda.gov/vs/nahps/scrapie Maryland Small Ruminant Page www.sheepandgoat.com/scrapie.html National Institute of Animal Agriculture http://www.animalagriculture.org/scrapie/Scrapie.htm Scrapie QuickPlace https://qp01.aphis.usda.gov/QuickPlace/scrapie/Main.nsf?OpenDatabase State and federal employees can access this password-protected site by e-mailing Susan.E.Ledford@APHIS.USDA.gov to receive a password. American Sheep Industry Association www.sheepusa.org Since April 1, 2003: 161,909 samples collected 352 NVSL* confirmed positive In FY2008: 16,710 samples collected 10 NVSL confirmed positive * Through February 29, 2008
http://www.sheepusa.org/index.phtml?page=site/get_file&print=1&file_id=a565d8d1480eca6400d3a2adff9d89bc
Friday, April 11, 2008
SEAC SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE ANNUAL REPORT 2007
It is highly likely that sheep were exposed to BSE during the BSE epidemic in cattle. However, despite extensive Transmissible Spongiform Encephalopathy (TSE) surveillance in sheep there is no evidence that BSE is present in the UK sheep flock now. *{The relatively recent identification of atypical scrapie and paucity of experimental data about its transmissibility either between sheep or to humans have raised concerns about the possible animal and public health implications of this disease}*.
http://www.seac.gov.uk/publicats/annualreport2007.pdf
Tissue distribution. For atypical scrapie, what is PrPres and infectivity distribution within sheep of different genotypes, particularly with respect to SRM removal? For classical scrapie and experimental BSE in sheep, tissue distribution of infectivity is widespread. Thus, even with SRM controls in place, an infected sheep poses around 1000 times the risk to human health than does an infected cow22. Does the distribution depend on whether infection is by the oral or 21 Gubbins S. Prevalence of BSE in sheep: interpreting the results of retrospective and prospective testing of sheep TSE cases. SEAC 84 open meeting 22 paper presented to Food Standards Agency board on 9 December 2004. http://www.foodstandards.gov.uk/multimedia/pdfs/fsa041204.pdf Also see paper SEAC/84/2 Annex 2: McLean, A. Page 13 © SEAC 27 February 2006 intracerebral route? Are some VRQ sheep carriers with no neurological symptoms?
SEAC SHEEP SUBGROUP POSITION STATEMENT
http://www.seac.gov.uk/pdf/positionstatement-sheep-subgroup.pdf
P03.141
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute, Norway
Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. ***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
Published online before print October 20, 2005
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0502296102 Medical Sciences
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 * *Virologie Immunologie Moléculaires and Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway
Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved September 12, 2005 (received for review March 21, 2005)
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
http://www.pnas.org/cgi/content/abstract/0502296102v1
Like lambs to the slaughter
31 March 2001
Debora MacKenzie
Magazine issue 2284
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
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 ...
The complete article is 889 words long.
full text;
http://www.newscientist.com/article.ns?id=mg16922840.300
Neurobiology
Adaptation of the bovine spongiform encephalopathy agent to primates and comparison with Creutzfeldt- Jakob disease: Implications for human health Corinne Ida Lasmézas*,, Jean-Guy Fournier*, Virginie Nouvel*, Hermann Boe*, Domíníque Marcé*, François Lamoury*, Nicolas Kopp, Jean-Jacques Hauw§, James Ironside¶, Moira Bruce, Dominique Dormont*, and Jean-Philippe Deslys* * Commissariat à l'Energie Atomique, Service de Neurovirologie, Direction des Sciences du Vivant/Département de Recherche Medicale, Centre de Recherches du Service de Santé des Armées 60-68, Avenue du Général Leclerc, BP 6, 92 265 Fontenay-aux-Roses Cedex, France; Hôpital Neurologique Pierre Wertheimer, 59, Boulevard Pinel, 69003 Lyon, France; § Laboratoire de Neuropathologie, Hôpital de la Salpêtrière, 83, Boulevard de l'Hôpital, 75013 Paris, France; ¶ Creutzfeldt-Jakob Disease Surveillance Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; and Institute for Animal Health, Neuropathogenesis Unit, West Mains Road, Edinburgh EH9 3JF, United Kingdom
Edited by D. Carleton Gajdusek, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France, and approved December 7, 2000 (received for review October 16, 2000)
Abstract
There is substantial scientific evidence to support the notion that bovine spongiform encephalopathy (BSE) has contaminated human beings, causing variant Creutzfeldt-Jakob disease (vCJD). This disease has raised concerns about the possibility of an iatrogenic secondary transmission to humans, because the biological properties of the primate-adapted BSE agent are unknown. We show that (i) BSE can be transmitted from primate to primate by intravenous route in 25 months, and (ii) an iatrogenic transmission of vCJD to humans could be readily recognized pathologically, whether it occurs by the central or peripheral route. Strain typing in mice demonstrates that the BSE agent adapts to macaques in the same way as it does to humans and confirms that the BSE agent is responsible for vCJD not only in the United Kingdom but also in France. The agent responsible for French iatrogenic growth hormone-linked CJD taken as a control is very different from vCJD but is similar to that found in one case of sporadic CJD and one sheep scrapie isolate. These data will be key in identifying the origin of human cases of prion disease, including accidental vCJD transmission, and could provide bases for vCJD risk assessment.
http://www.pnas.org/cgi/content/full/041490898v1
typical scrapie transmits to primates by there NON-FORCED ORAL CONSUMPTION ;
76/10.12/4.6
http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=6997404&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus
snip...full text ;
http://nor-98.blogspot.com/2008/04/seac-spongiform-encephalopathy-advisory.html
Saturday, April 12, 2008
Evidence of scrapie transmission via milk
Research articleS
http://scrapie-usa.blogspot.com/2008/04/evidence-of-scrapie-transmission-via.html
NOR-98
http://nor-98.blogspot.com/
SCRAPIE USA
http://scrapie-usa.blogspot.com/
FOIA MAD SHEEP MAD RIVER VALLEY
http://foiamadsheepmadrivervalley.blogspot.com/
TSS
Saturday, April 12, 2008
Friday, April 11, 2008
SEAC SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE ANNUAL REPORT 2007
SEAC SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE
ANNUAL REPORT 2007
SEAC Annual Report 2007 1 Foreword
The continued decline in the incidence of Bovine Spongiform Encephalopathy (BSE) in the United Kingdom (UK) and elsewhere in Europe is very welcome. As a result, the European Union (EU) has been able to relax some of the control measures introduced to protect human and animal health, and is considering further relaxations. Whilst there are clear economic benefits to relaxing controls, the associated risks may be less well understood. During 2007, SEAC provided advice on the risks that may be associated with changes to specific controls, and advice on how these risks can be assessed. As the effectiveness of one control may be related to that of others, it is important that regulators consider the impact of specific changes, and combinations of changes, on the effectiveness of the control regime as a whole. Furthermore, it is vital that surveillance of animals and humans is in place that is capable of detecting any major adverse consequences of changes to the control regime should these arise. The recent identification of different, albeit apparently rare, forms of BSE, which were discussed by SEAC during the year, emphasises the need for continued vigilance.
It is highly likely that sheep were exposed to BSE during the BSE epidemic in cattle. However, despite extensive Transmissible Spongiform Encephalopathy (TSE) surveillance in sheep there is no evidence that BSE is present in the UK sheep flock now. *{The relatively recent identification of atypical scrapie and paucity of experimental data about its transmissibility either between sheep or to humans have raised concerns about the possible animal and public health implications of this disease}*. Although atypical scrapie has been identified in a number of EU Member States, no clusters of cases have been found. It is, therefore, considered that this disease may have a low rate of transmission between sheep. It is possible, therefore, that atypical scrapie, like classical scrapie, may have existed for some considerable time without any apparent association with human TSEs. Nevertheless, the human health implications need to be clarified. SEAC will continue to monitor closely the results from research underway to assess the human and animal health implications of atypical scrapie. Encouragingly there was only one new diagnosed case of variant Creutzfeldt-Jakob Disease (vCJD) in 2007. However, uncertainty remains about the number of individuals that may be infected with vCJD but who are not showing clinical signs of the disease (subclinical infections). It is critical to ascertain better the prevalence of subclinical infections. This is because the assumed presence of these infections is the reason costly interventions have been introduced (depletion of white blood cells from blood donations, deferral of blood recipients from donating blood and single-use instruments for certain types of surgery and dentistry) to minimise the potential risk of human-to-human transmission of vCJD. During 2007, SEAC reviewed the analysis of the first tranche of results from the National Anonymous Tonsil Archive (NATA). None of the tonsils tested to date (more than 45 000) has been found to be positive for abnormal prion protein.
SEAC Annual Report 2007
Thus, NATA provides no evidence to suggest that a large epidemic of subclinical infections exists. However, there is still uncertainty about how early during the preclinical phase abnormal prion protein accumulates in tonsil tissue and therefore, how reliably tonsil testing is able to detect subclinical infections. It is also the case that, a large proportion of tonsils removed comes from young people with little or no likelihood of dietary exposure to BSE. For these reasons, SEAC continues to stress the need for a post mortem tissue archive to complement the data from NATA. Together NATA and a post mortem tissue archive would allow the wide range of estimated prevalence of subclinical vCJD infections to be narrowed, facilitating better risk assessments of potential human to human transmission of the disease, and analyses to justify costly current and future interventions. New risk assessments considered by SEAC during 2007 suggest that, under certain circumstances, dentistry, like blood transfusion and surgery, may provide a route for vCJD infection to be passed between people. Following advice from SEAC, the Department of Health issued guidance to dentists in 2007 about making certain types of dental instruments single use as a precautionary measure to prevent possible vCJD transmission via certain dental procedures. SEAC strongly encourages the work already underway to improve the decontamination of dental and surgical instruments and to develop blood tests that will allow the risks of vCJD transmission to be reduced. I was pleased to welcome Professors John Collinge and Azra Ghani and Drs Richard Knight and Roland Salmon onto the committee in 2007. I was also pleased to accept my reappointment for a second term as Chair. The committee is very appreciative of the researchers that have shared important unpublished data to allow SEAC and its Subgroups early consideration of important findings. I would like to thank Kate Richards, who moved to a new post during the year, Dr Tom Barlow who stood in as Acting SEAC Secretary, and welcome Dr Peter Grimley as Kate’s successor as SEAC Secretary. I would also like to thank the members of SEAC and its Subgroups for their commitment and the expertise they bring to SEAC and the Secretariat for the support it provides the committee.
Professor Chris Higgins Chair of SEAC
http://www.seac.gov.uk/publicats/annualreport2007.pdf
*{The relatively recent identification of atypical scrapie and paucity of experimental data about its transmissibility either between sheep or to humans have raised concerns about the possible animal and public health implications of this disease}*.
IN FY 2007 TWO FIELD CASES, ONE VALIDATION CASE, AND TWO RSSS CASES WERE CONSISTENT WITH NOR-98 SCRAPIE. ...
(BRINGS A TOTAL OF 5 NOR-98 CASES DOCUMENTED IN 2007 IN USA. ...TSS)
The flocks of origin are WY, CO, CA, IN, and MN. personal communication USDA et al. ...TSS
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps
Tissue distribution. For atypical scrapie, what is PrPres and infectivity distribution within sheep of different genotypes, particularly with respect to SRM removal? For classical scrapie and experimental BSE in sheep, tissue distribution of infectivity is widespread. Thus, even with SRM controls in place, an infected sheep poses around 1000 times the risk to human health than does an infected cow22. Does the distribution depend on whether infection is by the oral or 21 Gubbins S. Prevalence of BSE in sheep: interpreting the results of retrospective and prospective testing of sheep TSE cases. SEAC 84 open meeting 22 paper presented to Food Standards Agency board on 9 December 2004. http://www.foodstandards.gov.uk/multimedia/pdfs/fsa041204.pdf Also see paper SEAC/84/2 Annex 2: McLean, A. Page 13 © SEAC 27 February 2006 intracerebral route? Are some VRQ sheep carriers with no neurological symptoms?
SEAC SHEEP SUBGROUP POSITION STATEMENT
http://www.seac.gov.uk/pdf/positionstatement-sheep-subgroup.pdf
P03.141
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute, Norway
Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. ***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
Published online before print October 20, 2005
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0502296102 Medical Sciences
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 * *Virologie Immunologie Moléculaires and Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway
Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved September 12, 2005 (received for review March 21, 2005)
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
http://www.pnas.org/cgi/content/abstract/0502296102v1
Like lambs to the slaughter
31 March 2001
Debora MacKenzie
Magazine issue 2284
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
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 ...
The complete article is 889 words long.
full text;
http://www.newscientist.com/article.ns?id=mg16922840.300
Neurobiology
Adaptation of the bovine spongiform encephalopathy agent to primates and comparison with Creutzfeldt- Jakob disease: Implications for human health Corinne Ida Lasmézas*,, Jean-Guy Fournier*, Virginie Nouvel*, Hermann Boe*, Domíníque Marcé*, François Lamoury*, Nicolas Kopp, Jean-Jacques Hauw§, James Ironside¶, Moira Bruce, Dominique Dormont*, and Jean-Philippe Deslys* * Commissariat à l'Energie Atomique, Service de Neurovirologie, Direction des Sciences du Vivant/Département de Recherche Medicale, Centre de Recherches du Service de Santé des Armées 60-68, Avenue du Général Leclerc, BP 6, 92 265 Fontenay-aux-Roses Cedex, France; Hôpital Neurologique Pierre Wertheimer, 59, Boulevard Pinel, 69003 Lyon, France; § Laboratoire de Neuropathologie, Hôpital de la Salpêtrière, 83, Boulevard de l'Hôpital, 75013 Paris, France; ¶ Creutzfeldt-Jakob Disease Surveillance Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; and Institute for Animal Health, Neuropathogenesis Unit, West Mains Road, Edinburgh EH9 3JF, United Kingdom
Edited by D. Carleton Gajdusek, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France, and approved December 7, 2000 (received for review October 16, 2000)
Abstract
There is substantial scientific evidence to support the notion that bovine spongiform encephalopathy (BSE) has contaminated human beings, causing variant Creutzfeldt-Jakob disease (vCJD). This disease has raised concerns about the possibility of an iatrogenic secondary transmission to humans, because the biological properties of the primate-adapted BSE agent are unknown. We show that (i) BSE can be transmitted from primate to primate by intravenous route in 25 months, and (ii) an iatrogenic transmission of vCJD to humans could be readily recognized pathologically, whether it occurs by the central or peripheral route. Strain typing in mice demonstrates that the BSE agent adapts to macaques in the same way as it does to humans and confirms that the BSE agent is responsible for vCJD not only in the United Kingdom but also in France. The agent responsible for French iatrogenic growth hormone-linked CJD taken as a control is very different from vCJD but is similar to that found in one case of sporadic CJD and one sheep scrapie isolate. These data will be key in identifying the origin of human cases of prion disease, including accidental vCJD transmission, and could provide bases for vCJD risk assessment.
http://www.pnas.org/cgi/content/full/041490898v1
NOR-98 ATYPICAL SCRAPIE USA UPDATE AS AT OCT 2007
typical scrapie transmits to primates by there NON-FORCED ORAL CONSUMPTION ;
76/10.12/4.6
http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=6997404&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus
EVIDENCE OF SCRAPIE IN SHEEP AS A RESULT OF FOOD BORNE EXPOSURE
This is provided by the statistically significant increase in the incidence of sheep scrape from 1985, as determined from analyses of the submissions made to VI Centres, and from individual case and flock incident studies. ........
http://www.bseinquiry.gov.uk/files/yb/1994/02/07002001.pdf
SCRAPIE USA UPDATE MONTHLY REPORT JANUARY 2008
prepared February 20, 2008
Infected and Source Flocks
There were 27 scrapie infected and source flocks with open statuses (Figure 3) as of January 31, 2008. Two new source flocks and one new infected flock were reported in January (Figure 4) with a total of 22 reported for FY 2008 (Figure 5). ....
snip...
Positive Scrapie Cases
As of January 31, 2008, 58 new scrapie cases have been confirmed and reported by the National Veterinary Services Laboratories (NVSL) in FY 2008 (Figure 7). Of these, 52 were field cases and 6* were Regulatory Scrapie Slaughter Surveillance (RSSS) cases (collected in FY 2008 and reported by February 20, 2008). There were 8 positive cases for January which are depicted in Figure 8. Seventeen cases of scrapie in goats have been confirmed by NVSL since implementation of the regulatory changes in FY 2002 (Figure 9). The most recent positive goat cases were from the SAME HERD and WERE BOTH CONFIRMED IN JANAURY 2008.
snip...
Caprine Scrapie Prevalence Study (CSPS)
CSPS was initiated in May 2007 to estimate the national prevalance of scrapie in adult goats at slaughter. If no scrapie is found we will be able to conclude that the prevalence in goats is greater than zero and less than 0.1 percent. AS of January 31, 2008, 2,942 goats have been sampled for scrapie testing (1,515 in FY 2007 and 1,427 in FY 2008). Collection numbers by quarter in FY 2008 is shown in Chart 8. To date, no goats have tested positive for scrapie as part of this surveillance program. HOWEVER, THREE POSITIVE GOATS have been identified this fiscal year through field investigations. One was a clinical suspect submitted for testing and THE OTHER TWO WERE MEMBERS OF THE OF THE BIRTH HERD OF THE CLINICAL CASE.
snip...
please see full text ;
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps
full text ;
http://nor-98.blogspot.com/
http://scrapie-usa.blogspot.com/
FOIA MAD SHEEP MAD RIVER VALLEY
http://foiamadsheepmadrivervalley.blogspot.com/
TSS
ANNUAL REPORT 2007
SEAC Annual Report 2007 1 Foreword
The continued decline in the incidence of Bovine Spongiform Encephalopathy (BSE) in the United Kingdom (UK) and elsewhere in Europe is very welcome. As a result, the European Union (EU) has been able to relax some of the control measures introduced to protect human and animal health, and is considering further relaxations. Whilst there are clear economic benefits to relaxing controls, the associated risks may be less well understood. During 2007, SEAC provided advice on the risks that may be associated with changes to specific controls, and advice on how these risks can be assessed. As the effectiveness of one control may be related to that of others, it is important that regulators consider the impact of specific changes, and combinations of changes, on the effectiveness of the control regime as a whole. Furthermore, it is vital that surveillance of animals and humans is in place that is capable of detecting any major adverse consequences of changes to the control regime should these arise. The recent identification of different, albeit apparently rare, forms of BSE, which were discussed by SEAC during the year, emphasises the need for continued vigilance.
It is highly likely that sheep were exposed to BSE during the BSE epidemic in cattle. However, despite extensive Transmissible Spongiform Encephalopathy (TSE) surveillance in sheep there is no evidence that BSE is present in the UK sheep flock now. *{The relatively recent identification of atypical scrapie and paucity of experimental data about its transmissibility either between sheep or to humans have raised concerns about the possible animal and public health implications of this disease}*. Although atypical scrapie has been identified in a number of EU Member States, no clusters of cases have been found. It is, therefore, considered that this disease may have a low rate of transmission between sheep. It is possible, therefore, that atypical scrapie, like classical scrapie, may have existed for some considerable time without any apparent association with human TSEs. Nevertheless, the human health implications need to be clarified. SEAC will continue to monitor closely the results from research underway to assess the human and animal health implications of atypical scrapie. Encouragingly there was only one new diagnosed case of variant Creutzfeldt-Jakob Disease (vCJD) in 2007. However, uncertainty remains about the number of individuals that may be infected with vCJD but who are not showing clinical signs of the disease (subclinical infections). It is critical to ascertain better the prevalence of subclinical infections. This is because the assumed presence of these infections is the reason costly interventions have been introduced (depletion of white blood cells from blood donations, deferral of blood recipients from donating blood and single-use instruments for certain types of surgery and dentistry) to minimise the potential risk of human-to-human transmission of vCJD. During 2007, SEAC reviewed the analysis of the first tranche of results from the National Anonymous Tonsil Archive (NATA). None of the tonsils tested to date (more than 45 000) has been found to be positive for abnormal prion protein.
SEAC Annual Report 2007
Thus, NATA provides no evidence to suggest that a large epidemic of subclinical infections exists. However, there is still uncertainty about how early during the preclinical phase abnormal prion protein accumulates in tonsil tissue and therefore, how reliably tonsil testing is able to detect subclinical infections. It is also the case that, a large proportion of tonsils removed comes from young people with little or no likelihood of dietary exposure to BSE. For these reasons, SEAC continues to stress the need for a post mortem tissue archive to complement the data from NATA. Together NATA and a post mortem tissue archive would allow the wide range of estimated prevalence of subclinical vCJD infections to be narrowed, facilitating better risk assessments of potential human to human transmission of the disease, and analyses to justify costly current and future interventions. New risk assessments considered by SEAC during 2007 suggest that, under certain circumstances, dentistry, like blood transfusion and surgery, may provide a route for vCJD infection to be passed between people. Following advice from SEAC, the Department of Health issued guidance to dentists in 2007 about making certain types of dental instruments single use as a precautionary measure to prevent possible vCJD transmission via certain dental procedures. SEAC strongly encourages the work already underway to improve the decontamination of dental and surgical instruments and to develop blood tests that will allow the risks of vCJD transmission to be reduced. I was pleased to welcome Professors John Collinge and Azra Ghani and Drs Richard Knight and Roland Salmon onto the committee in 2007. I was also pleased to accept my reappointment for a second term as Chair. The committee is very appreciative of the researchers that have shared important unpublished data to allow SEAC and its Subgroups early consideration of important findings. I would like to thank Kate Richards, who moved to a new post during the year, Dr Tom Barlow who stood in as Acting SEAC Secretary, and welcome Dr Peter Grimley as Kate’s successor as SEAC Secretary. I would also like to thank the members of SEAC and its Subgroups for their commitment and the expertise they bring to SEAC and the Secretariat for the support it provides the committee.
Professor Chris Higgins Chair of SEAC
http://www.seac.gov.uk/publicats/annualreport2007.pdf
*{The relatively recent identification of atypical scrapie and paucity of experimental data about its transmissibility either between sheep or to humans have raised concerns about the possible animal and public health implications of this disease}*.
IN FY 2007 TWO FIELD CASES, ONE VALIDATION CASE, AND TWO RSSS CASES WERE CONSISTENT WITH NOR-98 SCRAPIE. ...
(BRINGS A TOTAL OF 5 NOR-98 CASES DOCUMENTED IN 2007 IN USA. ...TSS)
The flocks of origin are WY, CO, CA, IN, and MN. personal communication USDA et al. ...TSS
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps
Tissue distribution. For atypical scrapie, what is PrPres and infectivity distribution within sheep of different genotypes, particularly with respect to SRM removal? For classical scrapie and experimental BSE in sheep, tissue distribution of infectivity is widespread. Thus, even with SRM controls in place, an infected sheep poses around 1000 times the risk to human health than does an infected cow22. Does the distribution depend on whether infection is by the oral or 21 Gubbins S. Prevalence of BSE in sheep: interpreting the results of retrospective and prospective testing of sheep TSE cases. SEAC 84 open meeting 22 paper presented to Food Standards Agency board on 9 December 2004. http://www.foodstandards.gov.uk/multimedia/pdfs/fsa041204.pdf Also see paper SEAC/84/2 Annex 2: McLean, A. Page 13 © SEAC 27 February 2006 intracerebral route? Are some VRQ sheep carriers with no neurological symptoms?
SEAC SHEEP SUBGROUP POSITION STATEMENT
http://www.seac.gov.uk/pdf/positionstatement-sheep-subgroup.pdf
P03.141
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute, Norway
Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. ***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
Published online before print October 20, 2005
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0502296102 Medical Sciences
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 * *Virologie Immunologie Moléculaires and Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway
Edited by Stanley B. Prusiner, University of California, San Francisco, CA, and approved September 12, 2005 (received for review March 21, 2005)
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
http://www.pnas.org/cgi/content/abstract/0502296102v1
Like lambs to the slaughter
31 March 2001
Debora MacKenzie
Magazine issue 2284
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
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 ...
The complete article is 889 words long.
full text;
http://www.newscientist.com/article.ns?id=mg16922840.300
Neurobiology
Adaptation of the bovine spongiform encephalopathy agent to primates and comparison with Creutzfeldt- Jakob disease: Implications for human health Corinne Ida Lasmézas*,, Jean-Guy Fournier*, Virginie Nouvel*, Hermann Boe*, Domíníque Marcé*, François Lamoury*, Nicolas Kopp, Jean-Jacques Hauw§, James Ironside¶, Moira Bruce, Dominique Dormont*, and Jean-Philippe Deslys* * Commissariat à l'Energie Atomique, Service de Neurovirologie, Direction des Sciences du Vivant/Département de Recherche Medicale, Centre de Recherches du Service de Santé des Armées 60-68, Avenue du Général Leclerc, BP 6, 92 265 Fontenay-aux-Roses Cedex, France; Hôpital Neurologique Pierre Wertheimer, 59, Boulevard Pinel, 69003 Lyon, France; § Laboratoire de Neuropathologie, Hôpital de la Salpêtrière, 83, Boulevard de l'Hôpital, 75013 Paris, France; ¶ Creutzfeldt-Jakob Disease Surveillance Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; and Institute for Animal Health, Neuropathogenesis Unit, West Mains Road, Edinburgh EH9 3JF, United Kingdom
Edited by D. Carleton Gajdusek, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France, and approved December 7, 2000 (received for review October 16, 2000)
Abstract
There is substantial scientific evidence to support the notion that bovine spongiform encephalopathy (BSE) has contaminated human beings, causing variant Creutzfeldt-Jakob disease (vCJD). This disease has raised concerns about the possibility of an iatrogenic secondary transmission to humans, because the biological properties of the primate-adapted BSE agent are unknown. We show that (i) BSE can be transmitted from primate to primate by intravenous route in 25 months, and (ii) an iatrogenic transmission of vCJD to humans could be readily recognized pathologically, whether it occurs by the central or peripheral route. Strain typing in mice demonstrates that the BSE agent adapts to macaques in the same way as it does to humans and confirms that the BSE agent is responsible for vCJD not only in the United Kingdom but also in France. The agent responsible for French iatrogenic growth hormone-linked CJD taken as a control is very different from vCJD but is similar to that found in one case of sporadic CJD and one sheep scrapie isolate. These data will be key in identifying the origin of human cases of prion disease, including accidental vCJD transmission, and could provide bases for vCJD risk assessment.
http://www.pnas.org/cgi/content/full/041490898v1
NOR-98 ATYPICAL SCRAPIE USA UPDATE AS AT OCT 2007
typical scrapie transmits to primates by there NON-FORCED ORAL CONSUMPTION ;
76/10.12/4.6
http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=6997404&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus
EVIDENCE OF SCRAPIE IN SHEEP AS A RESULT OF FOOD BORNE EXPOSURE
This is provided by the statistically significant increase in the incidence of sheep scrape from 1985, as determined from analyses of the submissions made to VI Centres, and from individual case and flock incident studies. ........
http://www.bseinquiry.gov.uk/files/yb/1994/02/07002001.pdf
SCRAPIE USA UPDATE MONTHLY REPORT JANUARY 2008
prepared February 20, 2008
Infected and Source Flocks
There were 27 scrapie infected and source flocks with open statuses (Figure 3) as of January 31, 2008. Two new source flocks and one new infected flock were reported in January (Figure 4) with a total of 22 reported for FY 2008 (Figure 5). ....
snip...
Positive Scrapie Cases
As of January 31, 2008, 58 new scrapie cases have been confirmed and reported by the National Veterinary Services Laboratories (NVSL) in FY 2008 (Figure 7). Of these, 52 were field cases and 6* were Regulatory Scrapie Slaughter Surveillance (RSSS) cases (collected in FY 2008 and reported by February 20, 2008). There were 8 positive cases for January which are depicted in Figure 8. Seventeen cases of scrapie in goats have been confirmed by NVSL since implementation of the regulatory changes in FY 2002 (Figure 9). The most recent positive goat cases were from the SAME HERD and WERE BOTH CONFIRMED IN JANAURY 2008.
snip...
Caprine Scrapie Prevalence Study (CSPS)
CSPS was initiated in May 2007 to estimate the national prevalance of scrapie in adult goats at slaughter. If no scrapie is found we will be able to conclude that the prevalence in goats is greater than zero and less than 0.1 percent. AS of January 31, 2008, 2,942 goats have been sampled for scrapie testing (1,515 in FY 2007 and 1,427 in FY 2008). Collection numbers by quarter in FY 2008 is shown in Chart 8. To date, no goats have tested positive for scrapie as part of this surveillance program. HOWEVER, THREE POSITIVE GOATS have been identified this fiscal year through field investigations. One was a clinical suspect submitted for testing and THE OTHER TWO WERE MEMBERS OF THE OF THE BIRTH HERD OF THE CLINICAL CASE.
snip...
please see full text ;
http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps
full text ;
http://nor-98.blogspot.com/
http://scrapie-usa.blogspot.com/
FOIA MAD SHEEP MAD RIVER VALLEY
http://foiamadsheepmadrivervalley.blogspot.com/
TSS
Saturday, April 5, 2008
No temporal trends in the prevalence of atypical scrapie in British sheep, 2002-2006
No temporal trends in the prevalence of atypical scrapie in British sheep, 2002-2006
K. Marie McIntyre1§, Victor J. del Rio Vilas2 and Simon Gubbins1 1Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Surrey GU24 0NF, UK
2Centre for Epidemiology and Risk Analysis, Veterinary Laboratories Agency, Weybridge, New Haw, Addlestone, Surrey KT15 3NB, UK §Corresponding author Email addresses: KMM: marie.mcintyre@bbsrc.ac.uk VDRV: v.delriovilas@vla.defra.gsi.gov.uk SG: simon.gubbins@bbsrc.ac.uk
- 2 -
Abstract
Background
So-called atypical scrapie was first identified in Great Britain (GB) in 2002 following the introduction of wide-scale scrapie surveillance. In particular, abattoir and fallen stock surveys have been carried out in GB since 2002, with a total of 147 atypical positives identified by the end of 2006. The results of these surveys provide data with which to assess temporal trends in the prevalence of atypical scrapie in sheep in Great Britain between 2002 and 2006.
Results
Using the results of abattoir and fallen stock surveys, the prevalence of atypical scrapie (percentage of samples positive) was estimated. The prevalence in the abattoir and fallen stock surveys, for all years combined, was 0.09% (95% confidence interval (CI): 0.08%- 0.11%) and 0.07% (95% CI: 0.05%-0.11%), respectively. There were no significant temporal trends in either survey. Comparing the surveys’ results, there were no significant differences in annual prevalence or the prevalence within PrP genotypes. For the abattoir survey, the PrP genotype with the highest prevalence was AHQ/AHQ, which was significantly higher than all other genotypes, except ARR/AHQ, AHQ/ARH and ARH/ARQ.
Conclusions
The estimated prevalence of atypical scrapie was similar in both the abattoir and fallen stock surveys. Our results indicate there was no significant temporal trend in prevalence, adding to evidence that this atypical form of scrapie may be a sporadic condition or, if it is infectious, that the force of infection is very low.
snip...
Conclusions
The results of this study indicate that the prevalence of atypical scrapie did not change significantly between 2002 and 2006. Furthermore, it did not differ significantly between the abattoir and fallen stock surveys, which is not the case for classical scrapie. The absence of temporal trends in the prevalence of atypical scrapie adds to evidence that this may be a sporadic condition or, if it is infectious, the force of infection is very low. Recent experimental work has demonstrated that atypical scrapie is transmissible [33], but the evidence for whether or not it is infectious is mixed. Examination of demographic factors and trading patterns has suggested transmission of atypical scrapie could be occurring, albeit slowly [34] , suggesting it could be infectious. By contrast, a case control study of Nor98 in Norway found no risk factors to indicate transmission between flocks [35], suggesting atypical scrapie is sporadic. Ultimately, a combination of evidence from case-control studies, spatio-temporal analysis and laboratory experiments will be necessary to determine whether this disease is infectious or sporadic in nature. A similar approach was utilised in the case of arguments surrounding sporadic- versus variant-Creutzfeldt-Jakob disease [36].
http://www.biomedcentral.com/content/pdf/1746-6148-4-13.pdf
PLEASE note, in my opinion, there is absolutely no proof of or evidence what so ever of a natural field case of a spontaneous and or sporadic TSE in any species, anywhere.
WHY is it not possible for the potential of atypical scrapie transmitting the same way as typical scrapie ???
WHY is feed not a factor here ???
EVIDENCE OF SCRAPIE IN SHEEP AS A RESULT OF FOOD BORNE EXPOSURE
This is provided by the statistically significant increase in the incidence of sheep scrape from 1985, as determined from analyses of the submissions made to VI Centres, and from individual case and flock incident studies. ........
http://www.bseinquiry.gov.uk/files/yb/1994/02/07002001.pdf
STRICTLY PRIVATE AND CONFIDENTIAL 25, AUGUST 1995
snip...
To minimise the risk of farmers' claims for compensation from feed compounders.
To minimise the potential damage to compound feed markets through adverse publicity.
To maximise freedom of action for feed compounders, notably by maintaining the availability of meat and bone meal as a raw material in animal feeds, and ensuring time is available to make any changes which may be required.
snip...
THE FUTURE
4..........
MAFF remains under pressure in Brussels and is not skilled at handling potentially explosive issues.
5. Tests _may_ show that ruminant feeds have been sold which contain illegal traces of ruminant protein. More likely, a few positive test results will turn up but proof that a particular feed mill knowingly supplied it to a particular farm will be difficult if not impossible.
6. The threat remains real and it will be some years before feed compounders are free of it. The longer we can avoid any direct linkage between feed milling _practices_ and actual BSE cases, the more likely it is that serious damage can be avoided. ...
SEE full text ;
http://www.bseinquiry.gov.uk/files/yb/1995/08/24002001.pdf
TAFS INTERNATIONAL FORUM FOR TRANSMISSIBLE ANIMAL DISEASES AND FOOD SAFETY a non-profit Swiss Foundation (May 16, 2007) TAFS1 Position Paper on Atypical scrapie and Atypical BSE
Although most atypical cases occur singly in flocks, there are some instances where two affected sheep have been identified in flocks. This may indicate that natural transmission may occur, or that the sheep were infected from a common alternative source(22, 29). Possible indications of an association with the feeding of vitamins and mineral feed supplements were detected in Norway, but remain to be proven(22).
snip...
Atypical BSE may arise spontaneously in a small proportion of cattle. The existence of sporadic CJD in humans has led to postulation that disease could arise spontaneously in any animal, but this is still not proven to happen. Despite the small numbers of atypical BSE detected so far, in some countries the numbers are too great to suggest that they all arise spontaneously, if it were assumed that such aphenomenon occurred at the same frequency as sporadic CJD in humans.
http://www.tseandfoodsafety.org/position_papers/TAFS_POSITION_PAPER_ON_ATYPICAL_SCRAPIE_AND_%20ATYPICAL_BSE_070516.pdf
Tissue distribution. For atypical scrapie, what is PrPres and infectivity distribution within sheep of different genotypes, particularly with respect to SRM removal? For classical scrapie and experimental BSE in sheep, tissue distribution of infectivity is widespread. Thus, even with SRM controls in place, an infected sheep poses around 1000 times the risk to human health than does an infected cow22. Does the distribution depend on whether infection is by the oral or
21 Gubbins S. Prevalence of BSE in sheep: interpreting the results of retrospective and prospective testing of sheep TSE cases. SEAC 84 open meeting 22 paper presented to Food Standards Agency board on 9 December 2004. http://www.foodstandards.gov.uk/multimedia/pdfs/fsa041204.pdf Also see paper SEAC/84/2 Annex 2: McLean, A. Page 13 © SEAC 27 February 2006
intracerebral route? Are some VRQ sheep carriers with no neurological symptoms?
SEAC SHEEP SUBGROUP POSITION STATEMENT
http://www.seac.gov.uk/pdf/positionstatement-sheep-subgroup.pdf
P03.141
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute, Norway
Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. ***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
High incidence of subclinical infection of lymphoid tissues in scrapie-affected sheep flocks
Our findings indicate that contamination of the environment plays an important part in sustaining the infection.
http://www.springerlink.com/content/u761171744280806/
http://scrapie-usa.blogspot.com/2008/03/high-incidence-of-subclinical-infection.html
NOR-98 ATYPICAL SCRAPIE USA UPDATE AS AT OCT 2007
typical scrapie transmits to primates by there NON-FORCED ORAL CONSUMPTION ;
76/10.12/4.6
http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=6997404&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus
full text ;
SCRAPIE TYPICAL AND ATYPICAL USA
ATYPICAL NOR-98 SCRAPIE
LOCATION UPDATE ON 5 DOCUMENTED CASES THIS YEAR ;
The flocks of origin are WY, CO, CA, IN, and MN.
personal communication USDA et al. ...TSS
http://nor-98.blogspot.com/
http://scrapie-usa.blogspot.com/
TSS
K. Marie McIntyre1§, Victor J. del Rio Vilas2 and Simon Gubbins1 1Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Surrey GU24 0NF, UK
2Centre for Epidemiology and Risk Analysis, Veterinary Laboratories Agency, Weybridge, New Haw, Addlestone, Surrey KT15 3NB, UK §Corresponding author Email addresses: KMM: marie.mcintyre@bbsrc.ac.uk VDRV: v.delriovilas@vla.defra.gsi.gov.uk SG: simon.gubbins@bbsrc.ac.uk
- 2 -
Abstract
Background
So-called atypical scrapie was first identified in Great Britain (GB) in 2002 following the introduction of wide-scale scrapie surveillance. In particular, abattoir and fallen stock surveys have been carried out in GB since 2002, with a total of 147 atypical positives identified by the end of 2006. The results of these surveys provide data with which to assess temporal trends in the prevalence of atypical scrapie in sheep in Great Britain between 2002 and 2006.
Results
Using the results of abattoir and fallen stock surveys, the prevalence of atypical scrapie (percentage of samples positive) was estimated. The prevalence in the abattoir and fallen stock surveys, for all years combined, was 0.09% (95% confidence interval (CI): 0.08%- 0.11%) and 0.07% (95% CI: 0.05%-0.11%), respectively. There were no significant temporal trends in either survey. Comparing the surveys’ results, there were no significant differences in annual prevalence or the prevalence within PrP genotypes. For the abattoir survey, the PrP genotype with the highest prevalence was AHQ/AHQ, which was significantly higher than all other genotypes, except ARR/AHQ, AHQ/ARH and ARH/ARQ.
Conclusions
The estimated prevalence of atypical scrapie was similar in both the abattoir and fallen stock surveys. Our results indicate there was no significant temporal trend in prevalence, adding to evidence that this atypical form of scrapie may be a sporadic condition or, if it is infectious, that the force of infection is very low.
snip...
Conclusions
The results of this study indicate that the prevalence of atypical scrapie did not change significantly between 2002 and 2006. Furthermore, it did not differ significantly between the abattoir and fallen stock surveys, which is not the case for classical scrapie. The absence of temporal trends in the prevalence of atypical scrapie adds to evidence that this may be a sporadic condition or, if it is infectious, the force of infection is very low. Recent experimental work has demonstrated that atypical scrapie is transmissible [33], but the evidence for whether or not it is infectious is mixed. Examination of demographic factors and trading patterns has suggested transmission of atypical scrapie could be occurring, albeit slowly [34] , suggesting it could be infectious. By contrast, a case control study of Nor98 in Norway found no risk factors to indicate transmission between flocks [35], suggesting atypical scrapie is sporadic. Ultimately, a combination of evidence from case-control studies, spatio-temporal analysis and laboratory experiments will be necessary to determine whether this disease is infectious or sporadic in nature. A similar approach was utilised in the case of arguments surrounding sporadic- versus variant-Creutzfeldt-Jakob disease [36].
http://www.biomedcentral.com/content/pdf/1746-6148-4-13.pdf
PLEASE note, in my opinion, there is absolutely no proof of or evidence what so ever of a natural field case of a spontaneous and or sporadic TSE in any species, anywhere.
WHY is it not possible for the potential of atypical scrapie transmitting the same way as typical scrapie ???
WHY is feed not a factor here ???
EVIDENCE OF SCRAPIE IN SHEEP AS A RESULT OF FOOD BORNE EXPOSURE
This is provided by the statistically significant increase in the incidence of sheep scrape from 1985, as determined from analyses of the submissions made to VI Centres, and from individual case and flock incident studies. ........
http://www.bseinquiry.gov.uk/files/yb/1994/02/07002001.pdf
STRICTLY PRIVATE AND CONFIDENTIAL 25, AUGUST 1995
snip...
To minimise the risk of farmers' claims for compensation from feed compounders.
To minimise the potential damage to compound feed markets through adverse publicity.
To maximise freedom of action for feed compounders, notably by maintaining the availability of meat and bone meal as a raw material in animal feeds, and ensuring time is available to make any changes which may be required.
snip...
THE FUTURE
4..........
MAFF remains under pressure in Brussels and is not skilled at handling potentially explosive issues.
5. Tests _may_ show that ruminant feeds have been sold which contain illegal traces of ruminant protein. More likely, a few positive test results will turn up but proof that a particular feed mill knowingly supplied it to a particular farm will be difficult if not impossible.
6. The threat remains real and it will be some years before feed compounders are free of it. The longer we can avoid any direct linkage between feed milling _practices_ and actual BSE cases, the more likely it is that serious damage can be avoided. ...
SEE full text ;
http://www.bseinquiry.gov.uk/files/yb/1995/08/24002001.pdf
TAFS INTERNATIONAL FORUM FOR TRANSMISSIBLE ANIMAL DISEASES AND FOOD SAFETY a non-profit Swiss Foundation (May 16, 2007) TAFS1 Position Paper on Atypical scrapie and Atypical BSE
Although most atypical cases occur singly in flocks, there are some instances where two affected sheep have been identified in flocks. This may indicate that natural transmission may occur, or that the sheep were infected from a common alternative source(22, 29). Possible indications of an association with the feeding of vitamins and mineral feed supplements were detected in Norway, but remain to be proven(22).
snip...
Atypical BSE may arise spontaneously in a small proportion of cattle. The existence of sporadic CJD in humans has led to postulation that disease could arise spontaneously in any animal, but this is still not proven to happen. Despite the small numbers of atypical BSE detected so far, in some countries the numbers are too great to suggest that they all arise spontaneously, if it were assumed that such aphenomenon occurred at the same frequency as sporadic CJD in humans.
http://www.tseandfoodsafety.org/position_papers/TAFS_POSITION_PAPER_ON_ATYPICAL_SCRAPIE_AND_%20ATYPICAL_BSE_070516.pdf
Tissue distribution. For atypical scrapie, what is PrPres and infectivity distribution within sheep of different genotypes, particularly with respect to SRM removal? For classical scrapie and experimental BSE in sheep, tissue distribution of infectivity is widespread. Thus, even with SRM controls in place, an infected sheep poses around 1000 times the risk to human health than does an infected cow22. Does the distribution depend on whether infection is by the oral or
21 Gubbins S. Prevalence of BSE in sheep: interpreting the results of retrospective and prospective testing of sheep TSE cases. SEAC 84 open meeting 22 paper presented to Food Standards Agency board on 9 December 2004. http://www.foodstandards.gov.uk/multimedia/pdfs/fsa041204.pdf Also see paper SEAC/84/2 Annex 2: McLean, A. Page 13 © SEAC 27 February 2006
intracerebral route? Are some VRQ sheep carriers with no neurological symptoms?
SEAC SHEEP SUBGROUP POSITION STATEMENT
http://www.seac.gov.uk/pdf/positionstatement-sheep-subgroup.pdf
P03.141
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute, Norway
Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. ***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
http://www.prion2007.com/pdf/Prion%20Book%20of%20Abstracts.pdf
High incidence of subclinical infection of lymphoid tissues in scrapie-affected sheep flocks
Our findings indicate that contamination of the environment plays an important part in sustaining the infection.
http://www.springerlink.com/content/u761171744280806/
http://scrapie-usa.blogspot.com/2008/03/high-incidence-of-subclinical-infection.html
NOR-98 ATYPICAL SCRAPIE USA UPDATE AS AT OCT 2007
typical scrapie transmits to primates by there NON-FORCED ORAL CONSUMPTION ;
76/10.12/4.6
http://www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=6997404&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus
full text ;
SCRAPIE TYPICAL AND ATYPICAL USA
ATYPICAL NOR-98 SCRAPIE
LOCATION UPDATE ON 5 DOCUMENTED CASES THIS YEAR ;
The flocks of origin are WY, CO, CA, IN, and MN.
personal communication USDA et al. ...TSS
http://nor-98.blogspot.com/
http://scrapie-usa.blogspot.com/
TSS
Subscribe to:
Posts (Atom)