NIAA Annual Conference April 11-14, 2011San Antonio, Texas
Nor98-Like Scrapie Cases in the United States
Total number of cases since first detected in 2007
•12
Mean age of infected animals
•6 Years
Median age of infected animals
•5 years
Sex Distribution of infected animals
•12 females
Face Color Distribution of infected animals
•8 White or Minimally Mottled
•2 Mottled
•1 Black
•1 SoayClinical signs
•1 animal
Nor98-Like Scrapie Cases in the United States
Genotypes
•3 AFRQ/ALRQ
•2 AFRQ/AFRQ
•2 ALHQ/ALRQ
•2 ALRR/ALRR
•1 ALRQ/ALRQ
•1 ALHQ/ALHQ
•1 AFRQ/ALRRAllele
frequency
•8 AFRQ
•7 ALRQ
•5 ALRR
•4 ALHQ
RSSS InvestigationsFY 2011*
•6 classical scrapie positives detected.
•6 successfully traced back to flock of origin, resulting in 6 newly discovered Infected or Source flocks.
•No investigations pending.
* As of February 28, 2011
Scrapie Confirmed Cases inFY 2010
Classical scrapie cases = 72;
Nor98-like scrapie cases = 5
53 Field Cases;
24 RSSS cases (n) (Reported by State of ID tag). Each asterisk *indicates one Nor98-like case. Note: field cases include animals removed from infected/source flocks so the state totals often include several animals from the same flock.
Scrapie Confirmed Cases in FY 2011 as of February 28, 2011
Classical scrapie cases = 11; Nor98-like scrapie cases = 1
6 Field Cases;
6 RSSS cases (n) (Reported by State of ID tag). Each asterisk *indicates one Nor98-like case. Note: field cases include animals removed from infected/source flocks so the state totals often include several animals from the same flock.
Goat Scrapie Cases FY 2002 –FY 2011*
Total Goat Cases = 22
* Through February 28, 2011
http://www.animalagriculture.org/Solutions/Proceedings/Annual%20Conference/2011/Small%20Ruminant/Garrett,%20Joe.pdf
Monday, October 10, 2011
EFSA Journal 2011 The European Response to BSE: A Success Story
snip...
EFSA and the European Centre for Disease Prevention and Control (ECDC) recently delivered a scientific opinion on any possible epidemiological or molecular association between TSEs in animals and humans (EFSA Panel on Biological Hazards (BIOHAZ) and ECDC, 2011). This opinion confirmed Classical BSE prions as the only TSE agents demonstrated to be zoonotic so far but the possibility that a small proportion of human cases so far classified as "sporadic" CJD are of zoonotic origin could not be excluded. Moreover, transmission experiments to non-human primates suggest that some TSE agents in addition to Classical BSE prions in cattle (namely L-type Atypical BSE, Classical BSE in sheep, transmissible mink encephalopathy (TME) and chronic wasting disease (CWD) agents) might have zoonotic potential.
snip...
http://www.efsa.europa.eu/en/efsajournal/pub/e991.htm?emt=1
http://www.efsa.europa.eu/en/efsajournal/doc/e991.pdf
see follow-up here about North America BSE Mad Cow TSE prion risk factors, and the ever emerging strains of Transmissible Spongiform Encephalopathy in many species here in the USA, including humans ;
http://transmissiblespongiformencephalopathy.blogspot.com/2011/10/efsa-journal-2011-european-response-to.html
Monday, November 30, 2009
USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE
http://nor-98.blogspot.com/2009/11/usda-and-oie-collaborate-to-exclude.html
Friday, February 11, 2011
Atypical/Nor98 Scrapie Infectivity in Sheep Peripheral Tissues
http://nor-98.blogspot.com/2011/02/atypicalnor98-scrapie-infectivity-in.html
Sunday, December 12, 2010
EFSA reviews BSE/TSE infectivity in small ruminant tissues News Story 2 December 2010
http://transmissiblespongiformencephalopathy.blogspot.com/2010/12/efsa-reviews-bsetse-infectivity-in.html
Wednesday, January 18, 2012
Selection of Distinct Strain Phenotypes in Mice Infected by Ovine Natural Scrapie Isolates Similar to CH1641 Experimental Scrapie
Journal of Neuropathology & Experimental Neurology: February 2012 - Volume 71 - Issue 2 - p 140–147
http://transmissiblespongiformencephalopathy.blogspot.com/2012/01/selection-of-distinct-strain-phenotypes.html
Thursday, July 14, 2011
Histopathological Studies of "CH1641-Like" Scrapie Sources Versus Classical Scrapie and BSE Transmitted to Ovine Transgenic Mice (TgOvPrP4)
http://transmissiblespongiformencephalopathy.blogspot.com/2011/07/histopathological-studies-of-ch1641.html
Wednesday, January 18, 2012
BSE IN GOATS CAN BE MISTAKEN FOR SCRAPIE
February 1, 2012
http://transmissiblespongiformencephalopathy.blogspot.com/2012/01/bse-in-goats-can-be-mistaken-for.html
Thursday, December 23, 2010
Molecular Typing of Protease-Resistant Prion Protein in Transmissible Spongiform Encephalopathies of Small Ruminants, France, 2002-2009
Volume 17, Number 1 January 2011
http://transmissiblespongiformencephalopathy.blogspot.com/2010/12/molecular-typing-of-protease-resistant.html
Thursday, November 18, 2010
Increased susceptibility of human-PrP transgenic mice to bovine spongiform encephalopathy following passage in sheep
http://bse-atypical.blogspot.com/2010/11/increased-susceptibility-of-human-prp.html
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.
***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
PR-26
NOR98 SHOWS MOLECULAR FEATURES REMINISCENT OF GSS
R. Nonno1, E. Esposito1, G. Vaccari1, E. Bandino2, M. Conte1, B. Chiappini1, S. Marcon1, M. Di Bari1, S.L. Benestad3, U. Agrimi1 1 Istituto Superiore di Sanità, Department of Food Safety and Veterinary Public Health, Rome, Italy (romolo.nonno@iss.it); 2 Istituto Zooprofilattico della Sardegna, Sassari, Italy; 3 National Veterinary Institute, Department of Pathology, Oslo, Norway
Molecular variants of PrPSc are being increasingly investigated in sheep scrapie and are generally referred to as "atypical" scrapie, as opposed to "classical scrapie". Among the atypical group, Nor98 seems to be the best identified. We studied the molecular properties of Italian and Norwegian Nor98 samples by WB analysis of brain homogenates, either untreated, digested with different concentrations of proteinase K, or subjected to enzymatic deglycosylation. The identity of PrP fragments was inferred by means of antibodies spanning the full PrP sequence. We found that undigested brain homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11), truncated at both the C-terminus and the N-terminus, and not N-glycosylated. After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11. Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at the highest concentrations, similarly to PrP27-30 associated with classical scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment of 17 kDa with the same properties of PrP11, that was tentatively identified as a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in 2% sodium laurylsorcosine and is mainly produced from detergentsoluble, full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a sample with molecular and pathological properties consistent with Nor98 showed plaque-like deposits of PrPSc in the thalamus when the brain was analysed by PrPSc immunohistochemistry. Taken together, our results show that the distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids ~ 90-155. This fragment is produced by successive N-terminal and C-terminal cleavages from a full-length and largely detergent-soluble PrPSc, is produced in vivo and is extremely resistant to PK digestion.
*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.
119
http://www.neuroprion.com/pdf_docs/conferences/prion2006/abstract_book.pdf
A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes
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*,? +Author Affiliations
*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 (received for review March 21, 2005)
Abstract 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.
http://www.pnas.org/content/102/44/16031.abstract
Monday, December 1, 2008
When Atypical Scrapie cross species barriers
Authors
Andreoletti O., Herva M. H., Cassard H., Espinosa J. C., Lacroux C., Simon S., Padilla D., Benestad S. L., Lantier F., Schelcher F., Grassi J., Torres, J. M., UMR INRA ENVT 1225, Ecole Nationale Veterinaire de Toulouse.France; ICISA-INlA, Madrid, Spain; CEA, IBiTec-5, DSV, CEA/Saclay, Gif sur Yvette cedex, France; National Veterinary Institute, Postboks 750 Sentrum, 0106 Oslo, Norway, INRA IASP, Centre INRA de Tours, 3738O Nouzilly, France.
Content
Atypical scrapie is a TSE occurring in small ruminants and harbouring peculiar clinical, epidemiological and biochemical properties. Currently this form of disease is identified in a large number of countries. In this study we report the transmission of an atypical scrapie isolate through different species barriers as modeled by transgenic mice (Tg) expressing different species PRP sequence.
The donor isolate was collected in 1995 in a French commercial sheep flock. inoculation into AHQ/AHQ sheep induced a disease which had all neuro-pathological and biochemical characteristics of atypical scrapie. Transmitted into Transgenic mice expressing either ovine or PrPc, the isolate retained all the described characteristics of atypical scrapie.
Surprisingly the TSE agent characteristics were dramatically different v/hen passaged into Tg bovine mice. The recovered TSE agent had biological and biochemical characteristics similar to those of atypical BSE L in the same mouse model. Moreover, whereas no other TSE agent than BSE were shown to transmit into Tg porcine mice, atypical scrapie was able to develop into this model, albeit with low attack rate on first passage.
Furthermore, after adaptation in the porcine mouse model this prion showed similar biological and biochemical characteristics than BSE adapted to this porcine mouse model. Altogether these data indicate.
(i) the unsuspected potential abilities of atypical scrapie to cross species barriers
(ii) the possible capacity of this agent to acquire new characteristics when crossing species barrier
These findings raise some interrogation on the concept of TSE strain and on the origin of the diversity of the TSE agents and could have consequences on field TSE control measures.
http://www.neuroprion.org/resources/pdf_docs/conferences/prion2008/abstract-book-prion2008.pdf
Thursday, January 26, 2012
Facilitated Cross-Species Transmission of Prions in Extraneural Tissue
Science 27 January 2012: Vol. 335 no. 6067 pp. 472-475 DOI: 10.1126/science.1215659
http://transmissiblespongiformencephalopathy.blogspot.com/2012/01/facilitated-cross-species-transmission.html
Saturday, February 11, 2012
Prion cross-species transmission efficacy is tissue dependent
http://transmissiblespongiformencephalopathy.blogspot.com/2012/02/prion-cross-species-transmission.html
Thursday, January 26, 2012
The Risk of Prion Zoonoses
Science 27 January 2012: Vol. 335 no. 6067 pp. 411-413 DOI: 10.1126/science.1218167
http://transmissiblespongiformencephalopathy.blogspot.com/2012/01/risk-of-prion-zoonoses.html
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
12/10/76
AGRICULTURAL RESEARCH COUNCIL REPORT OF THE ADVISORY COMMITTE ON SCRAPIE
Office Note CHAIRMAN: PROFESSOR PETER WILDY
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A The Present Position with respect to Scrapie A] The Problem Scrapie is a natural disease of sheep and goats. It is a slow and inexorably progressive degenerative disorder of the nervous system and it ia fatal. It is enzootic in the United Kingdom but not in all countries. The field problem has been reviewed by a MAFF working group (ARC 35/77). It is difficult to assess the incidence in Britain for a variety of reasons but the disease causes serious financial loss; it is estimated that it cost Swaledale breeders alone $l.7 M during the five years 1971-1975. A further inestimable loss arises from the closure of certain export markets, in particular those of the United States, to British sheep. It is clear that scrapie in sheep is important commercially and for that reason alone effective measures to control it should be devised as quickly as possible. Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates.
One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias" Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
snip...
76/10.12/4.6
http://web.archive.org/web/20010305223125/www.bseinquiry.gov.uk/files/yb/1976/10/12004001.pdf
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
http://www.nature.com/nature/journal/v236/n5341/abs/236073a0.html
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
http://www.nature.com/nature/journal/v236/n5341/abs/236073a0.html
Wednesday, February 16, 2011
IN CONFIDENCE
SCRAPIE TRANSMISSION TO CHIMPANZEES
IN CONFIDENCE
http://scrapie-usa.blogspot.com/2011/02/in-confidence-scrapie-transmission-to.html
why do we not want to do TSE transmission studies on chimpanzees $
snip...
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
snip...
R. BRADLEY
http://collections.europarchive.org/tna/20080102222950/http://www.bseinquiry.gov.uk/files/yb/1990/09/23001001.pdf
Friday, February 11, 2011
Atypical/Nor98 Scrapie Infectivity in Sheep Peripheral Tissues
http://nor-98.blogspot.com/2011/02/atypicalnor98-scrapie-infectivity-in.html
Monday, April 25, 2011
Experimental Oral Transmission of Atypical Scrapie to Sheep
Volume 17, Number 5-May 2011
http://nor-98.blogspot.com/2011/04/experimental-oral-transmission-of.html
Sunday, April 18, 2010
SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
http://scrapie-usa.blogspot.com/2010/04/scrapie-and-atypical-scrapie.html
Thursday, November 18, 2010
Increased susceptibility of human-PrP transgenic mice to bovine spongiform encephalopathy following passage in sheep
http://bse-atypical.blogspot.com/2010/11/increased-susceptibility-of-human-prp.html
Wednesday, January 19, 2011
EFSA and ECDC review scientific evidence on possible links between TSEs in animals and humans Webnachricht 19 Januar 2011
http://transmissiblespongiformencephalopathy.blogspot.com/2011/01/efsa-and-ecdc-review-scientific.html
Monday, June 27, 2011
Comparison of Sheep Nor98 with Human Variably Protease-Sensitive Prionopathy and Gerstmann-Sträussler-Scheinker Disease
http://prionopathy.blogspot.com/2011/06/comparison-of-sheep-nor98-with-human.html
RESEARCH
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 17, No. 5, May 2011
Experimental Oral Transmission of Atypical Scrapie to Sheep
Marion M. Simmons, S. Jo Moore,1 Timm Konold, Lisa Thurston, Linda A. Terry, Leigh Thorne, Richard Lockey, Chris Vickery, Stephen A.C. Hawkins, Melanie J. Chaplin, and John Spiropoulos
To investigate the possibility of oral transmission of atypical scrapie in sheep and determine the distribution of infectivity in the animals’ peripheral tissues, we challenged neonatal lambs orally with atypical scrapie; they were then killed at 12 or 24 months. Screening test results were negative for disease-specifi c prion protein in all but 2 recipients; they had positive results for examination of brain, but negative for peripheral tissues. Infectivity of brain, distal ileum, and spleen from all animals was assessed in mouse bioassays; positive results were obtained from tissues that had negative results on screening. These fi ndings demonstrate that atypical scrapie can be transmitted orally and indicate that it has the potential for natural transmission and iatrogenic spread through animal feed. Detection of infectivity in tissues negative by current surveillance methods indicates that diagnostic sensitivity is suboptimal for atypical scrapie, and potentially infectious material may be able to pass into the human food chain.
SNIP...
Although we do not have epidemiologic evidence that supports the effi cient spread of disease in the fi eld, these data imply that disease is potentially transmissible under fi eld situations and that spread through animal feed may be possible if the current feed restrictions were to be relaxed. Additionally, almost no data are available on the potential for atypical scrapie to transmit to other food animal species, certainly by the oral route. However, work with transgenic mice has demonstrated the potential susceptibility of pigs, with the disturbing fi nding that the biochemical properties of the resulting PrPSc have changed on transmission (40). The implications of this observation for subsequent transmission and host target range are currently unknown.
How reassuring is this absence of detectable PrPSc from a public health perspective? The bioassays performed in this study are not titrations, so the infectious load of the positive gut tissues cannot be quantifi ed, although infectivity has been shown unequivocally. No experimental data are currently available on the zoonotic potential of atypical scrapie, either through experimental challenge of humanized mice or any meaningful epidemiologic correlation with human forms of TSE. However, the detection of infectivity in the distal ileum of animals as young as 12 months, in which all the tissues tested were negative for PrPSc by the currently available screening and confi rmatory diagnostic tests, indicates that the diagnostic sensitivity of current surveillance methods is suboptimal for detecting atypical scrapie and that potentially infectious material may be able to pass into the human food chain undetected.
Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 17, No. 5, May 2011
http://wwwnc.cdc.gov/eid/article/17/5/pdfs/10-1654.pdf
OIE Scrapie Chapter Revision • Current draft recognizes Nor98-like scrapie as a separate disease from classical scrapie • USDA provided comments on the draft to OIE
http://www.animalagriculture.org/Solutions/Proceedings/Annual%20Meeting/2009/Sheep%20&%20Goat/Myers,%20Thomas.pdf
Atypical scrapie/Nor 98 October 2009
Last year, after examining member country submissions and investigating rigorous scientific research, the World Organisation for Animal Health (OIE) decided that Nor 98 should not be listed in its Terrestrial Animal Health Code. The Code sets out trade recommendations or restrictions for listed diseases or conditions, and the OIE determined there was no need for such recommendations around Nor 98.
http://www.nzfsa.govt.nz/publications/ce-column/ce-web-nor98.htm
http://www.biosecurity.govt.nz/files/pests/atypical-scrapie/atypical-scrapie-faq-oct09.pdf
Sutton reported that USDA has urged the World Organization for Animal Health (OIE) to categorize Nor98-like scrapie as a separate disease from classical scrapie. Currently, the OIE has proposed a draft revision of their scrapie chapter that would exclude Nor98-like scrapie from the chapter. USDA will be submitting it's comments on this proposal soon.
http://www.ohiosheep.org/Events/ScrapieNewsletterMarch09.pdf
SCRAPIE
The United States is unable to support the proposed new draft Code Chapter on Scrapie. The draft chapter, as written, departs significantly from the existing chapter, is confusing and is difficult to understand. This version of the scrapie chapter uses much of the same wording as the BSE chapter and is written as if the predominance of evidence revealed that scrapie was a food-borne disease similar to BSE in cattle which is inappropriate. Moreover, several of the new changes are not supported by current scientific evidence. As a result, detailed comments on individual articles would not meaningful at this time.
The United States is not supportive of the proposed draft chapter for the following reasons: 1. Inclusion of “atypical” scrapie: The scientific evidence indicates that “atypical” scrapie, also referred to as Nor-98, Nor-98-like, or non-classical scrapie, is not the same disease as classical scrapie. Further, “atypical” scrapie does not meet the criteria for listing diseases of trade concern by the OIE, as described in Chapter 2.1.1 of the Code. The United States recommends that the scope of this chapter be limited to classical scrapie in sheep and goats. Further, the United States recommends that OIE clearly adopt the position that “atypical” scrapie represents a distinct disease entity from classical scrapie and that it not be a listed disease.
• There is no evidence that “atypical” scrapie is a contagious disease. If it is contagious, available evidence suggests that it has a much lower transmission efficiency. (Hopp, et al, 2006; Green, et al, 2007; Benestad, et al 2008; McIntyre, et al, 2008)
• The disease appears to be ubiquitous in that it has been found wherever sufficient surveillance has been conducted. (Buschmann et al, 2004; De Bosschere et al, 2004; Orge, et al, 2004; Everest et al, 2006; Arsac, 2007; Benestad, et al 2008; Fediaevsky, et al, 2008)
• The disease does not appear to be economically significant in that the prevalence of clinical disease is low and it typically occurs in older animals. (Luhken, et al., 2007; Benestad, et al 2008).
• The disease is as likely as not to be the result of a spontaneous conversion of normal prion protein. (Benestad, et al 2008, De Bosschere et al 2007)
• Removal of exposed sheep is unlikely to reduce the prevalence of “atypical” scrapie infection and removing only those exposed sheep that are phenylalanine (F) at codon 141 is scientifically unsound since the disease is known to affect sheep of most other genotypes. Further, sheep with AHQ alleles have a similar risk of infection with “atypical” strains as sheep with F at codon 141. (Luhken, et al., 2007).
• If “atypical” scrapie is included as a listed disease, the surveillance and diagnostic requirements which are needed to identify these cases should be described in detail in both this Chapter and the Manual of Diagnostic Tests and Vaccines for Terrestrial
2
Animals. Data from Europe illustrates that using the proper test(s) is essential for the identification of atypical scrapie (Fediaevsky et al., 2008).
SNIP...
6. Overemphasis on importation and use of bovine meat and bone meal as a route of scrapie transmission: Given that the draft Chapter is not intended to address risk mitigation for BSE in small ruminants, we believe there is an over-emphasis on this potential route of transmission in the current draft.
The United States recommends that the requirements in this chapter be limited to the inclusion of products from sheep and goats (instead of from all ruminants) in feed or feed ingredients intended for consumption by animals.
• The use of products from sheep and goats as feed or feed ingredients for ruminant or non-ruminant animals represent one possible route of transmission (Philippe, et al, 2005) and a source of environmental contamination with the classical scrapie agent. However, this is not the primary route of transmission for the scrapie agent.
• The need for the exclusion of cattle-derived protein or other animal protein to mitigate BSE risk should be based on a country’s BSE risk status and should be addressed in Chapter 2.3.13 of the Code.
SNIP...
14. Failure to provide scientific justification for the list of permitted commodities in Item 1 of Article 2.4.8.1. .
We recommend that the list be re-evaluated and those items that have not been substantiated as presenting no risk be excluded or those with some risk but where the intended use mitigates the risk the use be specified.
• There is no known human health risk associated with scrapie. As such, if meat and meat products for human consumption are included in this list, sheep and/or goat milk intended for human consumption should also be added to the list of permitted commodities in Item 1 of Article 2.4.8.1.
• In the vast majority of sheep infected with classical scrapie, actual infectivity or PrPres has been identified in most tissues including the lymphoreticular system (tonsils, spleen, lymph nodes), the gastrointestinal tract, brain, and spinal cord (Hadlow et. al. 1979; Hadlow et al., 1980; van Kuelen et al., 1996; van Kuelen et al., 1999, Andreoletti et al., 2000; Heggebø et al., 2002; Caplazi et al., 2004). Infectivity and/or PrPres has also been identified in the placenta (see Hourrigan et al., 1979; Onodera et al., 1993; Pattison et al., 1972; Pattison et al., 1974; Race et al., 1998), blood (Hunter et al., 2002; Houston et al. 2008); peripheral nerves (Groschup et al., 1996), muscle (Pattison and Millson, 1962; Andreoletti et al., 2004; Casalone et al., 2005), salivary gland (Hadlow et al., 1980; Vascellari et al., 2007), kidney (Siso et al., 2006), and skin ( Thomzig et al., 2007). In addition, recent work has shown milk and/or colostrum from scrapie infected ewes transmitted the disease to 17 of 18 lambs (Konold et al., 2008).
• The data on the risk of low protein tallow made from scrapie infected tissues particularly for use in milk replacer is limited and some epidemiologic studies suggest an association of milk replacer use with scrapie risk. Taylor et al., 1997 examined the inactivation capacity of different rendering system in regards to scrapie. The presence of infectivity was determined by bioassay into mice. From the onset of this study, it was assumed that tallow was not the vehicle for the transmission of TSE. Hence only 2 tallow samples were examined.
http://www.aphis.usda.gov/import_export/animals/oie/downloads/tahc_mar-sep08/tahc-scrapie-77-mar08_cmt.pdf
• Most critical is that atypical scrapie shows higher prevalence in so-called resistant ARR homozygote and heterozygote genotypes, compared with classical scrapie. • Atypical scrapie has not been found naturally in VRQ/VRQ sheep, although such sheep can be infected artificially. VRQ sheep are, in contrast, highly susceptible to classical scrapie. In the UK, one case of atypical scrapie has been found in VRQ heterozygote (AF141RQ/VRQ) sheep. It is important to ascertain whether or not VRQ-carrying sheep are significantly resistant to infection with atypical scrapie or whether the data might result from a failure to detect PrPres in atypical scrapie due to a different pattern of PrP distribution in tissues. • Increased incidence of atypical scrapie in sheep with PrP alleles carrying the variant phenylalanine (F) at position 141 (leucine(L)/phenylalanine) has also been observed compared with classical scrapie. • It will be important to clarify the genotype effect, particularly in relation to ARR and L141F in transmission studies. • In classical scrapie, there is clear evidence for a PrP genotype effect on tissue distribution patterns of PrPres. This might also be true for atypical scrapie although the data are less complete. 4. Transmission of atypical scrapie It has recently18 been demonstrated that atypical scrapie is experimentally transmissible to mice and sheep, primarily through intracerebral injection. There are some data suggesting that it may also be transmissible orally to sheep of different genotypes. The subgroup noted that challenge experiments with atypical scrapie in sheep were underway in the UK, with one successful intracerebral challenge to date. The subgroup was informed that positive transmission of infectivity from atypical scrapie isolated from sheep with a range of genotypes had been observed in mice. This included ovinised transgenic mice overexpressing the VRQ allele. Nor98 atypical scrapie had also transmitted to ARR ovinised mice, with transmission experiments in AF141RQ ovinised mice planned. Biochemical features of the isolates were maintained after transmission, and were distinct from BSE and classical scrapie. High infectivity titres were observed in brain tissue from atypical scrapie, including from ARR/ARR sheep. Brain transmission experiments in mice carrying the human PrP gene were at an early stage. 18 Le Dur A., Béringue V., Andréoletti O., Reine F., Laï T.H., Baron T., Bratberg B., Vilotte J.- L., Sarradin P., Benestad S.L. and Laude H.(2005) A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes. PNAS 102, 16031-16036
http://www.seac.gov.uk/pdf/positionstatement-sheep-subgroup.pdf
BSE: TIME TO TAKE H.B. PARRY SERIOUSLY
If the scrapie agent is generated from ovine DNA and thence causes disease in other species, then perhaps, bearing in mind the possible role of scrapie in CJD of humans (Davinpour et al, 1985), scrapie and not BSE should be the notifiable disease. ...
http://collections.europarchive.org/tna/20090505194948/http://bseinquiry.gov.uk/files/yb/1988/06/08004001.pdf
Thursday, February 23, 2012
Atypical Scrapie NOR-98 confirmed Alberta Canada sheep January 2012
http://transmissiblespongiformencephalopathy.blogspot.com/2012/02/atypical-scrapie-nor-98-confirmed.html
Monday, March 26, 2012
Texas Prepares for Chronic Wasting Disease CWD Possibility in Far West Texas
http://chronic-wasting-disease.blogspot.com/2012/03/texas-prepares-for-chronic-wasting.html
http://chronic-wasting-disease.blogspot.com/
Monday, March 19, 2012
Infectivity in Skeletal Muscle of Cattle with Atypical Bovine Spongiform Encephalopathy
PLoS One. 2012; 7(2): e31449.
http://transmissiblespongiformencephalopathy.blogspot.com/2012/03/infectivity-in-skeletal-muscle-of.html
Thursday, February 23, 2012
EIGHT FORMER SECRETARIES OF AGRICULTURE SPEAKING AT USDA'S 2012 AGRICULTURE OUTLOOK FORUM INDUCTED INTO USA MAD COW HALL OF SHAME
http://madcowusda.blogspot.com/2012/02/eight-former-secretaries-of-agriculture.html
Sunday, March 11, 2012
APHIS Proposes New Bovine Spongiform Encephalopathy Import Regulations in Line with International Animal Health Standards Proposal Aims to Ensure Health of the U.S. Beef Herd, Assist in Negotiations
http://transmissiblespongiformencephalopathy.blogspot.com/2012/03/aphis-proposes-new-bovine-spongiform.html
TSS
