Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats Terry Singeltary Sr. Submission
Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats Terry Singeltary Sr.
Submission
Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats
SUMMARY: We are reopening the comment period for our proposed rule that
would revise completely the scrapie regulations, which concern the risk groups
and categories established for individual animals and for flocks, the use of
genetic testing as a means of assigning risk levels to animals, movement
restrictions for animals found to be genetically less susceptible or resistant
to scrapie, and recordkeeping requirements. This action will allow interested
persons additional time to prepare and submit comments.DATES: The comment period
for the proposed rule published on September 10, 2015 (80 FR 54660-54692) is
reopened. We will consider all comments that we receive on or before December 9,
2015. ...
COMMENT SUBMISSION TERRY S. SINGELTARY SR.
WITH regards to Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats, I
kindly submit the following ;
>>>The last major revision of the scrapie regulations occurred on
August 21, 2001, when we published in theFederal Register(66 FR 43964, Docket
No. 97-093-5) a final rule amending part 79 by imposing additional restrictions
on the interstate movement of sheep and goats.<<<
Indeed, much science has changed about the Scrapie TSE prion, including
more science linking Scrapie to humans. sadly, politics, industry, and trade,
have not changed, and those usually trump sound science, as is the case with all
Transmissible Spongiform Encephalopathy TSE Prion disease in livestock producing
animals and the OIE. we can look no further at the legal trading of the Scrapie
TSE prion both typical and atypical of all strains, and CWD all stains. With as
much science of old, and now more new science to back this up, Scrapie of all
types i.e. atypical and typical, BSE all strains, and CWD all strains, should be
regulated in trade as BSE TSE PRION. In fact, I urge APHIS et al and the OIE,
and all trading partners to take heed to the latest science on the TSE prion
disease, all of them, and seriously reconsider the blatant disregards for human
and animal health, all in the name of trade, with the continued relaxing of TSE
Prion trade regulations through the ‘NEGLIGIBLE BSE RISK’ PROGRAM, which was set
up to fail in the first place. If the world does not go back to the ‘BSE RISK
ASSESSMENTS’, enhance, and or change that assessment process to include all TSE
prion disease, i.e. ‘TSE RISK ASSESSMENT’, if we do not do this and if we
continue this farce with OIE and the USDA et al, and the ‘NEGLIGIBLE BSE RISK’
PROGRAM, we will never eradicate the TSE prion aka mad cow type disease, they
will continue to mutate and spread among species of human and animal origin, and
they will continue to kill. ...
please see ;
O.05: Transmission of prions to primates after extended silent incubation
periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Val erie Durand, Sophie Luccantoni,
Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys
Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies
reputed to be transmissible under field conditions since decades. The
transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that
an animal PD might be zoonotic under appropriate conditions. Contrarily, in the
absence of obvious (epidemiological or experimental) elements supporting a
transmission or genetic predispositions, PD, like the other proteinopathies, are
reputed to occur spontaneously (atpical animal prion strains, sporadic CJD
summing 80% of human prion cases). Non-human primate models provided the first
evidences supporting the transmissibiity of human prion strains and the zoonotic
potential of BSE. Among them, cynomolgus macaques brought major information for
BSE risk assessment for human health (Chen, 2014), according to their
phylogenetic proximity to humans and extended lifetime. We used this model to
assess the zoonotic potential of other animal PD from bovine, ovine and cervid
origins even after very long silent incubation periods.
*** We recently observed the direct transmission of a natural classical
scrapie isolate to macaque after a 10-year silent incubation period,
***with features similar to some reported for human cases of sporadic CJD,
albeit requiring fourfold longe incubation than BSE. Scrapie, as recently evoked
in humanized mice (Cassard, 2014),
***is the third potentially zoonotic PD (with BSE and L-type BSE),
***thus questioning the origin of human sporadic cases. We will present an
updated panorama of our different transmission studies and discuss the
implications of such extended incubation periods on risk assessment of animal PD
for human health.
===============
***thus questioning the origin of human sporadic cases***
===============
***Our study demonstrates susceptibility of adult cattle to oral
transmission of classical BSE. ***
***our findings suggest that possible transmission risk of H-type BSE to
sheep and human. ***
P.86: Estimating the risk of transmission of BSE and scrapie to ruminants
and humans by protein misfolding cyclic amplification
Morikazu Imamura, Naoko Tabeta, Yoshifumi Iwamaru, and Yuichi Murayama
National Institute of Animal Health; Tsukuba, Japan
To assess the risk of the transmission of ruminant prions to ruminants and
humans at the molecular level, we investigated the ability of abnormal prion
protein (PrPSc) of typical and atypical BSEs (L-type and H-type) and typical
scrapie to convert normal prion protein (PrPC) from bovine, ovine, and human to
proteinase K-resistant PrPSc-like form (PrPres) using serial protein misfolding
cyclic amplification (PMCA).
Six rounds of serial PMCA was performed using 10% brain homogenates from
transgenic mice expressing bovine, ovine or human PrPC in combination with PrPSc
seed from typical and atypical BSE- or typical scrapie-infected brain
homogenates from native host species. In the conventional PMCA, the conversion
of PrPC to PrPres was observed only when the species of PrPC source and PrPSc
seed matched. However, in the PMCA with supplements (digitonin, synthetic polyA
and heparin), both bovine and ovine PrPC were converted by PrPSc from all tested
prion strains. On the other hand, human PrPC was converted by PrPSc from typical
and H-type BSE in this PMCA condition.
Although these results were not compatible with the previous reports
describing the lack of transmissibility of H-type BSE to ovine and human
transgenic mice, ***our findings suggest that possible transmission risk of
H-type BSE to sheep and human. Bioassay will be required to determine whether
the PMCA products are infectious to these animals.
================
***our findings suggest that possible transmission risk of H-type BSE to
sheep and human***
================
2015
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
*** Title: Transmission of scrapie prions to primate after an extended
silent incubation period Authors
item Comoy, Emmanuel - item Mikol, Jacqueline - item Luccantoni-Freire,
Sophie - item Correia, Evelyne - item Lescoutra-Etchegaray, Nathalie - item
Durand, Valérie - item Dehen, Capucine - item Andreoletti, Olivier - item
Casalone, Cristina - item Richt, Juergen item Greenlee, Justin item Baron,
Thierry - item Benestad, Sylvie - item Hills, Bob - item Brown, Paul - item
Deslys, Jean-Philippe -
Submitted to: Scientific Reports Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 28, 2015 Publication Date: June 30, 2015
Citation: Comoy, E.E., Mikol, J., Luccantoni-Freire, S., Correia, E.,
Lescoutra-Etchegaray, N., Durand, V., Dehen, C., Andreoletti, O., Casalone, C.,
Richt, J.A., Greenlee, J.J., Baron, T., Benestad, S., Brown, P., Deslys, J.
2015. Transmission of scrapie prions to primate after an extended silent
incubation period. Scientific Reports. 5:11573. Interpretive Summary: The
transmissible spongiform encephalopathies (also called prion diseases) are fatal
neurodegenerative diseases that affect animals and humans. The agent of prion
diseases is a misfolded form of the prion protein that is resistant to breakdown
by the host cells. Since all mammals express prion protein on the surface of
various cells such as neurons, all mammals are, in theory, capable of
replicating prion diseases. One example of a prion disease, bovine spongiform
encephalopathy (BSE; also called mad cow disease), has been shown to infect
cattle, sheep, exotic undulates, cats, non-human primates, and humans when the
new host is exposed to feeds or foods contaminated with the disease agent.
***The purpose of this study was to test whether non-human primates
(cynomologous macaque) are susceptible to the agent of sheep scrapie. After an
incubation period of approximately 10 years a macaque developed progressive
clinical signs suggestive of neurologic disease. Upon postmortem examination and
microscopic examination of tissues, there was a widespread distribution of
lesions consistent with a transmissible spongiform encephalopathy.
***This information will have a scientific impact since it is the first
study that demonstrates the transmission of scrapie to a non-human primate with
a close genetic relationship to humans. This information is especially useful to
regulatory officials and those involved with risk assessment of the potential
transmission of animal prion diseases to humans.
Technical Abstract: Classical bovine spongiform encephalopathy (c-BSE) is
an animal prion disease that also causes variant Creutzfeldt-Jakob disease in
humans. Over the past decades, c-BSE's zoonotic potential has been the driving
force in establishing extensive protective measures for animal and human health.
In complement to the recent demonstration that humanized mice are susceptible to
scrapie, we report here the first observation of direct transmission of a
natural classical scrapie isolate to a macaque after a 10-year incubation
period. Neuropathologic examination revealed all of the features of a prion
disease: spongiform change, neuronal loss, and accumulation of PrPres throughout
the CNS.
***This observation strengthens the questioning of the harmlessness of
scrapie to humans, at a time when protective measures for human and animal
health are being dismantled and reduced as c-BSE is considered controlled and
being eradicated. Our results underscore the importance of precautionary and
protective measures and the necessity for long-term experimental transmission
studies to assess the zoonotic potential of other animal prion strains.
Evidence for zoonotic potential of ovine scrapie prions
Hervé Cassard,1, n1 Juan-Maria Torres,2, n1 Caroline Lacroux,1, Jean-Yves
Douet,1, Sylvie L. Benestad,3, Frédéric Lantier,4, Séverine Lugan,1, Isabelle
Lantier,4, Pierrette Costes,1, Naima Aron,1, Fabienne Reine,5, Laetitia
Herzog,5, Juan-Carlos Espinosa,2, Vincent Beringue5, & Olivier Andréoletti1,
Affiliations Contributions Corresponding author Journal name: Nature
Communications Volume: 5, Article number: 5821 DOI: doi:10.1038/ncomms6821
Received 07 August 2014 Accepted 10 November 2014 Published 16 December 2014
Article tools Citation Reprints Rights & permissions Article metrics
Abstract
Although Bovine Spongiform Encephalopathy (BSE) is the cause of variant
Creutzfeldt Jakob disease (vCJD) in humans, the zoonotic potential of scrapie
prions remains unknown. Mice genetically engineered to overexpress the human
prion protein (tgHu) have emerged as highly relevant models for gauging the
capacity of prions to transmit to humans. These models can propagate human
prions without any apparent transmission barrier and have been used used to
confirm the zoonotic ability of BSE. Here we show that a panel of sheep scrapie
prions transmit to several tgHu mice models with an efficiency comparable to
that of cattle BSE. The serial transmission of different scrapie isolates in
these mice led to the propagation of prions that are phenotypically identical to
those causing sporadic CJD (sCJD) in humans. These results demonstrate that
scrapie prions have a zoonotic potential and raise new questions about the
possible link between animal and human prions.
Subject terms: Biological sciences• Medical research At a glance
***The serial transmission of different scrapie isolates in these mice led
to the propagation of prions that are phenotypically identical to those causing
sporadic CJD (sCJD) in humans.***
***These results demonstrate that scrapie prions have a zoonotic potential
and raise new questions about the possible link between animal and human
prions.***
why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely
create alarm in some circles even if the result could not be interpreted for
man. I have a view that all these agents could be transmitted provided a large
enough dose by appropriate routes was given and the animals kept long enough.
Until the mechanisms of the species barrier are more clearly understood it might
be best to retain that hypothesis.
snip...
R. BRADLEY
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to
nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep
and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were
exposed to the infectious agents only by their nonforced consumption of known
infectious tissues. The asymptomatic incubation period in the one monkey exposed
to the virus of kuru was 36 months; that in the two monkeys exposed to the virus
of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the
two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively.
Careful physical examination of the buccal cavities of all of the monkeys failed
to reveal signs or oral lesions. One additional monkey similarly exposed to kuru
has remained asymptomatic during the 39 months that it has been under
observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie
by natural feeding to squirrel monkeys that we have reported provides further
grounds for concern that scrapie-infected meat may occasionally give rise in
humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is
transmissible to man. This has followed reports that the disease has been
transmitted to primates. One particularly lurid speculation (Gajdusek 1977)
conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and
transmissible encephalopathy of mink are varieties of a single "virus". The U.S.
Department of Agriculture concluded that it could "no longer justify or permit
scrapie-blood line and scrapie-exposed sheep and goats to be processed for human
or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is
emphasised by the finding that some strains of scrapie produce lesions identical
to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be
transmissible to man raises two considerations. First, the safety of laboratory
personnel requires prompt attention. Second, action such as the "scorched meat"
policy of USDA makes the solution of the acrapie problem urgent if the sheep
industry is not to suffer grievously.
snip...
76/10.12/4.6
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC.
Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK
National Institute of Neurological Diseases and Stroke, National Institutes
of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey
(Macaca fascicularis) with an incubation period of more than 5 yr from the time
of intracerebral inoculation of scrapie-infected mouse brain. The animal
developed a chronic central nervous system degeneration, with ataxia, tremor and
myoclonus with associated severe scrapie-like pathology of intensive astroglial
hypertrophy and proliferation, neuronal vacuolation and status spongiosus of
grey matter. The strain of scrapie virus used was the eighth passage in Swiss
mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral
passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton,
Berkshire).
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.
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
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.
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.
Friday, February 11, 2011
Atypical/Nor98 Scrapie Infectivity in Sheep Peripheral Tissues
To think of Scrapie as the prime agent to compare CJD, but yet overlook the
Louping-ill vaccine event in 1930's of which 1000's of sheep where infected by
scrapie from a vaccine made of scrapie infected sheep brains, would be foolish.
I acquired this full text version of the event which was recorded in the Annual
Congress of 1946 National Vet. Med. Ass. of Great Britain and Ireland. from the
BVA and the URL is posted in my (long version).
OR, remember the infamous Louping-ill vaccine that caused some many scrapie
cases here ;
From: TSS (216-119-138-163.ipset18.wt.net)
Subject: Louping-ill vaccine documents from November 23rd, 1946
Date: September 10, 2000 at 8:57 am PST
Subject: Louping-ill vaccine documents from November 23rd, 1946
Date: Sat, 9 Sep 2000 17:44:57 –0700
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy
To: BSE-L@uni-karlsruhe.de
######### Bovine Spongiform Encephalopathy #########
THE VETERINARY RECORD 516 No 47. Vol. 58 November 23rd, 1946
NATIONAL VETERINARY MEDICAL ASSOCIATION OF GREAT BRITAIN AND IRELAND
ANNUAL CONGRESS, 1946
The annual Congress, 1946, was held at the Royal Veterinary College, Royal
College Street, London, N.W.I. from September 22nd to September 27th.
Opening Meeting
[skip to scrapie vaccine issue...tss]
Papers Presented to Congress
The papers presented to this year's Congress had as their general theme the
progressive work of the profession during the war years. Their appeal was
clearly demonstrated by the large and remarkably uniform attendance in the Grand
Hall of the Royal Veterinary College throughout the series; between 200 and 250
members were present and they showed a keen interest in every paper, which was
reflected in the expression of some disappointment that the time available for
discussion did not permit of the participation of more than a small proportion
of would-be contributors.
In this issue we publish (below) the first to be read and discussed, that
by Dr. W. S. Gordon, M.R.C.V.S., F.R.S.E., "Advances in Veterinary Research."
Next week's issue will contain the paper on "Some Recent Advances in Veterinary
Medicine and Surgery in Large-Animal Practice" by Mr. T. Norman Gold, M.R.C.V.S.
In succeeding numbers of the Record will be reproduced, also with reports of
discussions, that by Mr. W. L. Weipers, M.R.C.V.S., D.V.S.M., on the same
subject as relating to small-animal practice, and the papers by Mr. J. N.
Ritchie, B.SC., M.R.C.V.S., D.V.S.M., and Mr. H.W. Steele-Bodger, M.R.C.V.S., on
"War-time Achievements of the British Home Veterinary Services."
The first scientific paper of Congress was read by Dr. W. S. Gordon,
M.R.C.V.S., F.R.S.E. on Monday, September 23rd, 1946, when Professor J. Basil
Buxton, M.A., F.R.C.V.S, D.V.H., Prinicipal of the Royal Veterinary College,
presided.
Advances in Veterinary Research
by
W.S. GORDON, PH.D., M.R.C.V.S., F.R.S.E.
Agriculteral Research Council, Field Station, Compton, Berks.
Louping-ill, Tick-borne Fever and Scrapie
In 1930 Pool, Browniee & Wilson recorded that louping-ill was a
transmissible disease. Greig et al, (1931) showed that the infective agent was a
filter-passing virus with neurotropic characters and Browniee & Wilson
(1932) that the essential pathology was that of an encephalomyelitis. Gordon,
Browniee, Wilson & MacLeod (1932) and MacLeod & Gordon (1932) confirmed
and extended this work. It was shown that on louping-ill farms the virus was
present in the blood of many sheep which did not show clinical symptoms
indicating involvement of the central nervous system and that for the
perpetuation and spread of the disease these subclinical cases were probably of
greater importance that the frank clinical cases because, in Nature, the disease
was spread by the tick, lxodes ricinus L. More recently Wilson (1945, 1946) has
described the cultivation of the virus in a chick embryo medium, the pathogenic
properties of this culture virus and the preparation of louping-ill
antiserum.
Between 1931 and 1934 I carried out experiments which resulted in the
development of an effective vaccine for the prevention of louping-ill.* This
vaccine has been in general use since 1935 and in his annual report to the
Animal Diseases Research Association this year, Dr. Greig stated that about
227,000 doses of vaccine had been issued from Moredun alone.
Dr. Gordon illustrated this portion of his paper by means of graphs and
diagrams projected by the epidiascope.
This investigation, however, did not begin and end with the study of
louping-ill; it had, by good fortune, a more romantic turn and less fortunately
a final dramtic twist which led almost to catastrope. After it had been
established that a solid immunity to louping-ill could be induced in sheep, a
group of immunized and a group of susceptible animals were placed together on
the tick-infected pasture of a louping-ill farm. Each day all the animals were
gathered and their temperatures were recorded. It was anticipated that febrile
reactions with some fatalities would develop in the controls while the
louping-ill immunes would remain normal. Contrary to expectation, however, every
sheep, both immune and control, developed a febrile reaction. This unexpected
result made neccessary further investigation which showed that the febrile
reaction in the louping-ill immunes was due to a hitherto undescribed infective
agent, a Rickettsia-like organism which could be observed in the cytoplasm of
the grannular leucocytes, especially the neutrophil polymorphs (MacLeod (1932),
Gordon, Browniee, Wilson & MacLeod. MacLeod & Gordon (1933). MacLeod
(1936). MacLeod collected ticks over many widely separated parts of Scotland and
all were found to harbour the infective agent of tick-borne fever, and it is
probable that all sheep on tick-infested farms develop this disease, at least on
the first occasion that they become infested with ticks. When the infection is
passed in series through susceptible adult sheep it causes a sever, febrile
reaction, dullness and loss of bodily condition but it rarely, if ever, proves
fatal. It is clear, however, that it aggravates the harmful effects of a
louping-ill infection and it is a serious additional complication to such
infections as pyaemia and the anacrobic infections which beset lambs on the hill
farms of Northern Britain.
Studying the epidemiology of louping-ill on hill farms it became obvious
that the pyaemic condition of lambs described by M'Fadyean (1894) was very
prevalent on tick infested farms Pyaemia is a crippling condition of lambs
associated with tick-bite and is often confused with louping-ill. It is caused
by infection with Staphylococcus aureus and affected animals may show abscess
formation on the skin, in the joints, viscera, meninges and elsewhere in the
body. It was thought that tick-borne fever might have ben a predisposing factor
in this disease and unsuccessful attempts were made by Taylor, Holman &
Gordon (1941) to reproduce the condition by infecting lambs subcutaneously with
the staphylococcus and concurrently produceing infections with tickborne fever
and louping-ill in the same lambs. Work on pyaemia was then continued by
McDiarmid (1946a, 1946b, 1946c), who succeeded in reproducing a pyaemic disease
in mice, guinea-pigs and lambs similar to the naturally occuring condition by
intravenous inoculation of Staphylococcus aureus. He also found a bacteraemic
form of the disease in which no gross pyaemic lesions were observed. The
prevention or treatment of this condition presents a formidable problem. It is
unlikely that staphylococcal ???oid will provide an effective immunity and even
if penicillin proved to be a successful treatment, the difficulty of applying it
in adequate and sustained dosage to young lambs on hill farms would be almost
insurmountable.
From 1931 to 1934 field trials to test the immunizing value and
harmlessness of the loup-ill vaccine were carried out on a gradually increasing
scale. Many thousands of sheep were vaccinated and similar numbers, living under
identical conditions were left as controls. The end result showed that an
average mortability of about 9 percent in the controls was reduced to less than
1 percent in the vaccinated animals. While the efficiency of the vaccine was
obvious after the second year of work, previous bitter experience had shown the
wisdom of withholding a biological product from widespread use until it had been
successfully produced in bulk, as opposed to small-scale experimental production
and until it had been thoroughly tested for immunizing efficiency and freedom
from harmful effects. It was thought that after four years testing this stage
had been reached in 1935, and in the spring of that year the vaccine was issued
for general use. It comprised a 10 percent saline suspension of brain, spinal
cord and spleen tissues taken from sheep five days after infection with
louping-ill virus by intracerebral inoculation. To this suspension 0-35 percent
of formalin was added to inactivate the virus and its safety for use as a
vaccine was checked by intracerbral inoculation of mice and sheep and by the
inoculation of culture medium. Its protective power was proved by vaccination
sheep and later subjecting them, along with controls, to a test dose of living
virus.
Vaccine for issue had to be free from detectable, living virus and capable
of protecting sheep against a test dose of virus applied subcutaneously. The
1935 vaccine conformed to these standards and was issued for inoculation in
March as three separate batches labelled 1, 2, and 3. The tissues of 140 sheep
were employed to make batch 1 of which 22,270 doses were used; 114 to make batch
2 of which 18,000 doses were used and 44 to make batch 3 of which 4,360 doses
were used. All the sheep tissues incorporated in the vaccine were obtained from
yearling sheep. During 1935 and 1936 the vaccine proved highly efficient in the
prevention of loup-ill and no user observed an ill-effect in the inoculated
animals. In September, 1937, two and a half years after vaccinating the sheep,
two owners complained that scrapie, a disease which had not before been observed
in the Blackface breed, was appearing in their stock of Blackface sheep and
further that it was confined to animals vaccinated with louping-ill vaccine in
1935. At that stage it was difficult to conceive that the occurrence could be
associated with the injection of the vaccine but in view of the implications, I
visited most of the farms on which sheep had been vaccinated in 1935. It was at
this point that the investigation reached its dramatic phase; I shall not forget
the profound effect on my emotions when I visited these farms and was warmly
welcomed because of the great benefits resulting from the application of
louping-ill vaccine, wheras the chief purpose of my visit was to determine if
scrapie was appearing in the inoculated sheep. The enquiry made the position
clear. Scrapie was developing in the sheep vaccinated in 1935 and it was only in
a few instances that the owner was associating the occurrence with louping-ill
vaccination. The disease was affecting all breeds and it was confined to the
animals vaccinated with batch 2. This was clearly demonstrated on a number of
farms on which batch 1 had been used to inoculate the hoggs in 1935 and batch 2
to inoculate the ewes. None of the hoggs, which at this time were three-
year-old ewes. At this time it was difficult to forecast whether all of the
18,000 sheep which had received batch 2 vaccine would develop scrapie. It was
fortunate, however, that the majority of the sheep vaccinated with batch 2 were
ewes and therfore all that were four years old and upwards at the time of
vaccination had already been disposed of and there only remained the ewes which
had been two to three years old at the time of vaccination, consequently no
accurate assessment of the incidence of scrapie could be made. On a few farms,
however, where vaccination was confined to hoggs, the incidence ranged from 1
percent, to 35 percent, with an average of about 5 percent. Since batch 2
vaccine had been incriminated as a probable source of scrapie infection, an
attempt was made to trace the origin of the 112 sheep whose tissues had been
included in the vaccine. It was found that they had been supplied by three
owners and that all were of the Blackface or Greyface breed with the exception
of eight which were Cheviot lambs born in 1935 from ewes which had been in
contact with scrapie infection. Some of these contact ewes developed scrapie in
1936-37 and three surviving fellow lambs to the eight included in the batch 2
vaccine of 1935 developed scrapie, one in September, 1936, one in February,
1937, and one in November, 1937. There was, therefore, strong presumptive
evidence that the eight Cheviot lambs included in the vaccine althought
apparently healthy were, in fact, in the incubative stage of a scrapie infection
and that in their tissues there was an infective agent which had contaminated
the batch 2 vaccine, rendering it liable to set up scrapie. If that assumption
was correct then the evidence indicated that:-
(1) the infective agent of scrapie was present in the brain, spinal cord
and or spleen of infected sheep: (2) it could withstand a concentration of
formalin of 0-35 percent, which inactivated the virus of louping-ill: (3) it
could be transmitted by subcutaneous inoculation; (4) it had an incubative
period of two years and longer.
Two Frenchmen, Cuille & Chelle (1939) as the result of experiments
commenced in 1932, reported the successful infection of sheep by inoculation of
emulsions of spinal cord or brain material by the intracerebral, epidural,
intraocular and subcutaneous routes The incubation period varied according to
the route employed, being one year intracerebrally, 15 months intraocularly and
20 months subcutaneously. They failed to infect rabbits but succeeded in
infecting goats. Another important part of their work showed that the infective
agent could pass throught a chamberland 1.3 filter, thus demonstrating that the
infective agent was a filtrable virus. It was a curious coincidence that while
they were doing their transmission experiments their work was being confirmed by
the unforeseeable infectivity of a formalinized tissue vaccine.
As a result of this experience a large-scale transmision experiment
involving the ue of 788 sheep was commenced in 1938 on a farm specially taken
for the purpose by the Animal Diseases Research Association with funds provided
by the Agricultural Research Council. The experiment was designed to determine
the nature of the infective agent and the pathogenesis of the disease. It is
only possible here to give a summary of the result which showed that (1) saline
suspensions of brain and spinal cord tissue of sheep affected with scrapie were
infective to normal sheep when inoculatted intracerebrally or subcutaneously;
(2) the incubation period after intracerebral inoculation was seven months and
upwards and only 60 percent of the inoculated sheep developed scrapie during a
period of four and a half years; (3) the incubation period after subcutaneous
inoculation was 15 months and upwards and only about 30 percent of the
inoculated sheep developed the disease during the four and a half years: (4) the
infective agent was of small size and probably a filtrable virus.
The prolonged incubative period of the disease and the remarkable
resistance of the causal agent to formalin are features of distinct interest. It
still remains to determine if a biological test can be devised to detect
infected animals so that they can be killed for food before they develop
clinical symptoms and to explore the possibilities of producing an immunity to
the disease.
==================================================================
the next two items are for your files, some of you might find
interest...TSS
Thursday, August 20, 2015 Doctor William J. Hadlow
William J. Hadlow Dr. Hadlow (Ohio State ’48), 94, Hamilton, Montana, died
June 20, 2015.
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. ...
***2015 CWD TO HUMAN RISK FACTOR, PRICE OF POKER GOES UP ***
*** PRION 2015 CONFERENCE FT. COLLINS CWD RISK FACTORS TO HUMANS ***
*** LATE-BREAKING ABSTRACTS PRION 2015 CONFERENCE ***
O18
Zoonotic Potential of CWD Prions
Liuting Qing1, Ignazio Cali1,2, Jue Yuan1, Shenghai Huang3, Diane Kofskey1,
Pierluigi Gambetti1, Wenquan Zou1, Qingzhong Kong1 1Case Western Reserve
University, Cleveland, Ohio, USA, 2Second University of Naples, Naples, Italy,
3Encore Health Resources, Houston, Texas, USA
***These results indicate that the CWD prion has the potential to infect
human CNS and peripheral lymphoid tissues and that there might be asymptomatic
human carriers of CWD infection.***
P.105: RT-QuIC models trans-species prion transmission
Kristen Davenport, Davin Henderson, Candace Mathiason, and Edward Hoover
Prion Research Center; Colorado State University; Fort Collins, CO USA
Additionally, human rPrP was competent for conversion by CWD and fCWD.
***This insinuates that, at the level of protein:protein interactions, the
barrier preventing transmission of CWD to humans is less robust than previously
estimated.***
From: Terry S. Singeltary Sr.
Sent: Saturday, November 15, 2014 9:29 PM
To: Terry S. Singeltary Sr.
Subject: THE EPIDEMIOLOGY OF CREUTZFELDT-JAKOB DISEASE R. G. WILL 1984
THE EPIDEMIOLOGY OF CREUTZFELDT-JAKOB DISEASE
R. G. WILL
1984
*** The association between venison eating and risk of CJD shows similar
pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK
OF CJD (p = 0.04). (SEE LINK IN REPORT HERE...TSS) PLUS, THE CDC DID NOT PUT
THIS WARNING OUT FOR THE WELL BEING OF THE DEER AND ELK ;
snip...
85%+ of all human tse prion disease is sporadic CJD.
see what the NIH prion Gods say themselves ;
‘’In the Archives of Neurology you quoted (the abstract of which was
attached to your email), we did not say CWD in humans will present like variant
CJD. That assumption would be wrong.’’
‘’Also, we do not claim that "no-one has ever been infected with prion
disease from eating venison." Our conclusion stating that we found no strong
evidence of CWD transmission to humans in the article you quoted or in any other
forum is limited to the patients we investigated.’’
*** These results would seem to suggest that CWD does indeed have zoonotic
potential, at least as judged by the compatibility of CWD prions and their human
PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests
that if zoonotic CWD occurred, it would most likely effect those of the PRNP
codon 129-MM genotype and that the PrPres type would be similar to that found in
the most common subtype of sCJD (MM1).***
*** The potential impact of prion diseases on human health was greatly
magnified by the recognition that interspecies transfer of BSE to humans by beef
ingestion resulted in vCJD. While changes in animal feed constituents and
slaughter practices appear to have curtailed vCJD, there is concern that CWD of
free-ranging deer and elk in the U.S. might also cross the species barrier.
Thus, consuming venison could be a source of human prion disease. Whether BSE
and CWD represent interspecies scrapie transfer or are newly arisen prion
diseases is unknown. Therefore, the possibility of transmission of prion disease
through other food animals cannot be ruled out. There is evidence that vCJD can
be transmitted through blood transfusion. There is likely a pool of unknown size
of asymptomatic individuals infected with vCJD, and there may be asymptomatic
individuals infected with the CWD equivalent. These circumstances represent a
potential threat to blood, blood products, and plasma supplies.
now, let’s see what the authors said about this casual link, personal
communications years ago. see where it is stated NO STRONG evidence. so, does
this mean there IS casual evidence ???? “Our conclusion stating that we found no
strong evidence of CWD transmission to humans”
From: TSS (216-119-163-189.ipset45.wt.net)
Subject: CWD aka MAD DEER/ELK TO HUMANS ???
Date: September 30, 2002 at 7:06 am PST
From: "Belay, Ermias"
To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"
Sent: Monday, September 30, 2002 9:22 AM
Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Dear Sir/Madam,
In the Archives of Neurology you quoted (the abstract of which was attached
to your email), we did not say CWD in humans will present like variant CJD. That
assumption would be wrong. I encourage you to read the whole article and call me
if you have questions or need more clarification (phone: 404-639-3091). Also, we
do not claim that "no-one has ever been infected with prion disease from eating
venison." Our conclusion stating that we found no strong evidence of CWD
transmission to humans in the article you quoted or in any other forum is
limited to the patients we investigated.
Ermias Belay, M.D. Centers for Disease Control and Prevention
-----Original Message-----
From: Sent: Sunday, September 29, 2002 10:15 AM
To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV
Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS
Sunday, November 10, 2002 6:26 PM ......snip........end..............TSS
Thursday, April 03, 2008
A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008
Apr 3;39(4):41 A prion disease of cervids: Chronic wasting disease Sigurdson CJ.
snip...
*** twenty-seven CJD patients who regularly consumed venison were reported
to the Surveillance Center***,
snip... full text ;
July's Milwaukee Journal Sentinel article did prod state officials to ask
CDC to investigate the cases of the three men who shared wild game feasts. The
two men the CDC is still investigating were 55 and 66 years old. But there's
also Kevin Boss, a Minnesota hunter who ate Barron County venison and died of
CJD at 41. And there's Jeff Schwan, whose Michigan Tech fraternity brothers used
to bring venison sausage back to the frat house. His mother, Terry, says that in
May 2001, Jeff, 26, began complaining about his vision. A friend noticed
misspellings in his e-mail, which was totally unlike him. Jeff began losing
weight. He became irritable and withdrawn. By the end of June, he couldn't
remember the four-digit code to open the garage door or when and how to feed his
parents' cats. At a family gathering in July, he stuck to his parents and
girlfriend, barely talking. "On the night we took him to the hospital, he was
speaking like he was drunk or high and I noticed his pupils were so dilated I
couldn't see the irises," his mother says. By then, Jeff was no longer able to
do even simple things on his computer at work, and "in the hospital, he couldn't
drink enough water." When he died on September 27, 2001, an autopsy confirmed he
had sporadic CJD.
In 2000, Belay looked into three CJD cases reported by The Denver Post, two
hunters who ate meat from animals killed in Wyoming and the daughter of a hunter
who ate venison from a plant that processed Colorado elk. All three died of CJD
before they were 30 years old. The CDC asked the USDA to kill 1,000 deer and elk
in the area where the men hunted. Belay and others reported their findings in
the Archives of Neurology, writing that although "circumstances suggested a link
between the three cases and chronic wasting disease, they could find no 'causal'
link." Which means, says Belay, "not a single one of those 1,000 deer tested
positive for CWD. For all we know, these cases may be CWD. What we have now
doesn't indicate a connection. That's reassuring, but it would be wrong to say
it will never happen."
So far, says NIH researcher Race, the two Wisconsin cases pinpointed by the
newspaper look like spontaneous CJD. "But we don't know how CWD would look in
human brains. It probably would look like some garden-variety sporadic CJD."
What the CDC will do with these cases and four others (three from Colorado and
Schwan from Upper Michigan), Race says, is "sequence the prion protein from
these people, inject it into mice and wait to see what the disease looks like in
their brains. That will take two years."
CJD is so rare in people under age 30, one case in a billion (leaving out
medical mishaps), that four cases under 30 is "very high," says Colorado
neurologist Bosque. "Then, if you add these other two from Wisconsin [cases in
the newspaper], six cases of CJD in people associated with venison is very, very
high." Only now, with Mary Riley, there are at least seven, and possibly eight,
with Steve, her dining companion. "It's not critical mass that matters,"
however, Belay says. "One case would do it for me." The chance that two people
who know each other would both contact CJD, like the two Wisconsin sportsmen, is
so unlikely, experts say, it would happen only once in 140 years.
Given the incubation period for TSEs in humans, it may require another
generation to write the final chapter on CWD in Wisconsin. "Does chronic wasting
disease pass into humans? We'll be able to answer that in 2022," says Race.
Meanwhile, the state has become part of an immense experiment.
I urge everyone to watch this video closely...terry
*** you can see video here and interview with Jeff's Mom, and scientist
telling you to test everything and potential risk factors for humans ***
*** These results would seem to suggest that CWD does indeed have zoonotic
potential, at least as judged by the compatibility of CWD prions and their human
PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests
that if zoonotic CWD occurred, it would most likely effect those of the PRNP
codon 129-MM genotype and that the PrPres type would be similar to that found in
the most common subtype of sCJD (MM1).***
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Transmission of the agent of sheep scrapie to deer results in PrPSc
with two distinct molecular profiles Authors
item Greenlee, Justin item Moore, Sarah - item Smith, Jodi item West
Greenlee, Mary - item Kunkle, Robert
Submitted to: Prion Publication Type: Abstract Only Publication Acceptance
Date: March 31, 2015 Publication Date: May 25, 2015 Citation: Greenlee, J.,
Moore, S.J., Smith, J.., West Greenlee, M.H., Kunkle, R. 2015.
Scrapie transmits to white-tailed deer by the oral route and has a
molecular profile similar to chronic wasting disease and distinct from the
scrapie inoculum. Prion 2015. p. S62. Technical Abstract: The purpose of this
work was to determine susceptibility of white-tailed deer (WTD) to the agent of
sheep scrapie and to compare the resultant PrPSc to that of the original
inoculum and chronic wasting disease (CWD). We inoculated WTD by a natural route
of exposure (concurrent oral and intranasal (IN); n=5) with a US scrapie
isolate. All scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc
was detected in lymphoid tissues at preclinical time points, and deer necropsied
after 28 months post-inoculation had clinical signs, spongiform encephalopathy,
and widespread distribution of PrPSc in neural and lymphoid tissues. Western
blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral
cortex had a profile similar to the original scrapie inoculum, whereas WB of
brainstem, cerebellum, or lymph nodes reveal PrPSc with a higher profile
resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical
scrapie were further passaged to mice expressing cervid prion protein and
intranasally to sheep and WTD. In cervidized mice, the two inocula have distinct
incubation times. Sheep inoculated intranasally with WTD derived scrapie
developed disease, but only after inoculation with the inoculum that had a
scrapie-like profile. The WTD study is ongoing, but deer in both inoculation
groups are positive for PrPSc by rectal mucosal biopsy. In summary, this work
demonstrates that WTD are susceptible to the agent of scrapie, two distinct
molecular profiles of PrPSc are present in the tissues of affected deer, and
inoculum of either profile type readily passes to deer.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Scrapie transmits to white-tailed deer by the oral route and has a
molecular profile similar to chronic wasting disease Authors
item Greenlee, Justin item Moore, S - item Smith, Jodi - item Kunkle,
Robert item West Greenlee, M -
Submitted to: American College of Veterinary Pathologists Meeting
Publication Type: Abstract Only Publication Acceptance Date: August 12, 2015
Publication Date: N/A
Technical Abstract: The purpose of this work was to determine
susceptibility of white-tailed deer (WTD) to the agent of sheep scrapie and to
compare the resultant PrPSc to that of the original inoculum and chronic wasting
disease (CWD). We inoculated WTD by a natural route of exposure (concurrent oral
and intranasal (IN); n=5) with a US scrapie isolate. All scrapie-inoculated deer
had evidence of PrPSc accumulation. PrPSc was detected in lymphoid tissues at
preclinical time points, and deer necropsied after 28 months post-inoculation
had clinical signs, spongiform encephalopathy, and widespread distribution of
PrPSc in neural and lymphoid tissues. Western blotting (WB) revealed PrPSc with
2 distinct molecular profiles. WB on cerebral cortex had a profile similar to
the original scrapie inoculum, whereas WB of brainstem, cerebellum, or lymph
nodes revealed PrPSc with a higher profile resembling CWD. Homogenates with the
2 distinct profiles from WTD with clinical scrapie were further passaged to mice
expressing cervid prion protein and intranasally to sheep and WTD. In cervidized
mice, the two inocula have distinct incubation times. Sheep inoculated
intranasally with WTD derived scrapie developed disease, but only after
inoculation with the inoculum that had a scrapie-like profile. The WTD study is
ongoing, but deer in both inoculation groups are positive for PrPSc by rectal
mucosal biopsy. In summary, this work demonstrates that WTD are susceptible to
the agent of scrapie, two distinct molecular profiles of PrPSc are present in
the tissues of affected deer, and inoculum of either profile readily passes to
deer.
Sunday, October 25, 2015
USAHA Detailed Events Schedule – 119th USAHA Annual Meeting CAPTIVE
LIVESTOCK CWD SCRAPIE TSE PRION
Saturday, November 14, 2015
*** TEXAS CAPTIVE BREEDER CHRONIC WASTING DISEASE CWD 2 MORE SUSPECTS
DECTECTED
Thursday, November 05, 2015
*** TPW Commission Adopts Interim Deer Breeder Movement Rules ***
Wednesday, March 18, 2015
*** Chronic Wasting Disease CWD Confirmed Texas Trans Pecos March 18, 2015
(8 cases CWD in wild to date Texas)
Wednesday, March 25, 2015
*** Chronic Wasting Disease CWD Cases Confirmed In New Mexico 2013 and 2014
UPDATE 2015
*** Spraker suggested an interesting explanation for the occurrence of CWD.
The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr.
Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at
this site. When deer were introduced to the pens they occupied ground that had
previously been occupied by sheep.
White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection
Jodi D. Smith, Justin J. Greenlee, and Robert A. Kunkle; Virus and Prion
Research Unit, National Animal Disease Center, USDA-ARS
Interspecies transmission studies afford the opportunity to better
understand the potential host range and origins of prion diseases. Previous
experiments demonstrated that white-tailed deer are susceptible to sheep-derived
scrapie by intracranial inoculation. The purpose of this study was to determine
susceptibility of white-tailed deer to scrapie after a natural route of
exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal
(1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep
clinically affected with scrapie. Non-inoculated deer were maintained as
negative controls. All deer were observed daily for clinical signs. Deer were
euthanized and necropsied when neurologic disease was evident, and tissues were
examined for abnormal prion protein (PrPSc) by immunohistochemistry (IHC) and
western blot (WB). One animal was euthanized 15 months post-inoculation (MPI)
due to an injury. At that time, examination of obex and lymphoid tissues by IHC
was positive, but WB of obex and colliculus were negative. Remaining deer
developed clinical signs of wasting and mental depression and were necropsied
from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and
WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal
and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work
demonstrates for the first time that white-tailed deer are susceptible to sheep
scrapie by potential natural routes of inoculation. In-depth analysis of tissues
will be done to determine similarities between scrapie in deer after
intracranial and oral/intranasal inoculation and chronic wasting disease
resulting from similar routes of inoculation.
see full text ;
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed
deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture;
Agricultural Research Service, National Animal Disease Center; Ames, IA USA
White-tailed deer are susceptible to the agent of sheep scrapie by
intracerebral inoculation
snip...
It is unlikely that CWD will be eradicated from free-ranging cervids, and
the disease is likely to continue to spread geographically [10]. However, the
potential that white-tailed deer may be susceptible to sheep scrapie by a
natural route presents an additional confounding factor to halting the spread of
CWD. This leads to the additional speculations that
1) infected deer could serve as a reservoir to infect sheep with scrapie
offering challenges to scrapie eradication efforts and
2) CWD spread need not remain geographically confined to current endemic
areas, but could occur anywhere that sheep with scrapie and susceptible cervids
cohabitate.
This work demonstrates for the first time that white-tailed deer are
susceptible to sheep scrapie by intracerebral inoculation with a high attack
rate and that the disease that results has similarities to CWD. These
experiments will be repeated with a more natural route of inoculation to
determine the likelihood of the potential transmission of sheep scrapie to
white-tailed deer. If scrapie were to occur in white-tailed deer, results of
this study indicate that it would be detected as a TSE, but may be difficult to
differentiate from CWD without in-depth biochemical analysis.
2012
PO-039: A comparison of scrapie and chronic wasting disease in white-tailed
deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture;
Agricultural Research Service, National Animal Disease Center; Ames, IA USA
snip...
The results of this study suggest that there are many similarities in the
manifestation of CWD and scrapie in WTD after IC inoculation including early and
widespread presence of PrPSc in lymphoid tissues, clinical signs of depression
and weight loss progressing to wasting, and an incubation time of 21-23 months.
Moreover, western blots (WB) done on brain material from the obex region have a
molecular profile similar to CWD and distinct from tissues of the cerebrum or
the scrapie inoculum. However, results of microscopic and IHC examination
indicate that there are differences between the lesions expected in CWD and
those that occur in deer with scrapie: amyloid plaques were not noted in any
sections of brain examined from these deer and the pattern of immunoreactivity
by IHC was diffuse rather than plaque-like.
*** After a natural route of exposure, 100% of WTD were susceptible to
scrapie.
Deer developed clinical signs of wasting and mental depression and were
necropsied from 28 to 33 months PI. Tissues from these deer were positive for
PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer
exhibited two different molecular profiles: samples from obex resembled CWD
whereas those from cerebrum were similar to the original scrapie inoculum. On
further examination by WB using a panel of antibodies, the tissues from deer
with scrapie exhibit properties differing from tissues either from sheep with
scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are
strongly immunoreactive when probed with mAb P4, however, samples from WTD with
scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4
or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly
immunoreactive and samples from WTD with scrapie are strongly positive. This
work demonstrates that WTD are highly susceptible to sheep scrapie, but on first
passage, scrapie in WTD is differentiable from CWD.
2011
*** After a natural route of exposure, 100% of white-tailed deer were
susceptible to scrapie.
Sunday, October 25, 2015
USAHA Detailed Events Schedule – 119th USAHA Annual Meeting CAPTIVE
LIVESTOCK CWD SCRAPIE TSE PRION
PL1
Using in vitro prion replication for high sensitive detection of prions and
prionlike proteins and for understanding mechanisms of transmission.
Claudio Soto
Mitchell Center for Alzheimer's diseases and related Brain disorders,
Department of Neurology, University of Texas Medical School at Houston.
Prion and prion-like proteins are misfolded protein aggregates with the
ability to selfpropagate to spread disease between cells, organs and in some
cases across individuals. I n T r a n s m i s s i b l e s p o n g i f o r m
encephalopathies (TSEs), prions are mostly composed by a misfolded form of the
prion protein (PrPSc), which propagates by transmitting its misfolding to the
normal prion protein (PrPC). The availability of a procedure to replicate prions
in the laboratory may be important to study the mechanism of prion and
prion-like spreading and to develop high sensitive detection of small quantities
of misfolded proteins in biological fluids, tissues and environmental samples.
Protein Misfolding Cyclic Amplification (PMCA) is a simple, fast and efficient
methodology to mimic prion replication in the test tube. PMCA is a platform
technology that may enable amplification of any prion-like misfolded protein
aggregating through a seeding/nucleation process. In TSEs, PMCA is able to
detect the equivalent of one single molecule of infectious PrPSc and propagate
prions that maintain high infectivity, strain properties and species
specificity. Using PMCA we have been able to detect PrPSc in blood and urine of
experimentally infected animals and humans affected by vCJD with high
sensitivity and specificity. Recently, we have expanded the principles of PMCA
to amplify amyloid-beta (Aβ) and alphasynuclein (α-syn) aggregates implicated in
Alzheimer's and Parkinson's diseases, respectively. Experiments are ongoing to
study the utility of this technology to detect Aβ and α-syn aggregates in
samples of CSF and blood from patients affected by these diseases.
=========================
***Recently, we have been using PMCA to study the role of environmental
prion contamination on the horizontal spreading of TSEs. These experiments have
focused on the study of the interaction of prions with plants and
environmentally relevant surfaces. Our results show that plants (both leaves and
roots) bind tightly to prions present in brain extracts and excreta (urine and
feces) and retain even small quantities of PrPSc for long periods of time.
Strikingly, ingestion of prioncontaminated leaves and roots produced disease
with a 100% attack rate and an incubation period not substantially longer than
feeding animals directly with scrapie brain homogenate. Furthermore, plants can
uptake prions from contaminated soil and transport them to different parts of
the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety
of environmentally relevant surfaces, including stones, wood, metals, plastic,
glass, cement, etc. Prion contaminated surfaces efficiently transmit prion
disease when these materials were directly injected into the brain of animals
and strikingly when the contaminated surfaces were just placed in the animal
cage. These findings demonstrate that environmental materials can efficiently
bind infectious prions and act as carriers of infectivity, suggesting that they
may play an important role in the horizontal transmission of the disease.
========================
Since its invention 13 years ago, PMCA has helped to answer fundamental
questions of prion propagation and has broad applications in research areas
including the food industry, blood bank safety and human and veterinary disease
diagnosis.
see ;
98 | Veterinary Record | January 24, 2015
EDITORIAL
Scrapie: a particularly persistent pathogen
Cristina Acín
Resistant prions in the environment have been the sword of Damocles for
scrapie control and eradication. Attempts to establish which physical and
chemical agents could be applied to inactivate or moderate scrapie infectivity
were initiated in the 1960s and 1970s,with the first study of this type focusing
on the effect of heat treatment in reducing prion infectivity (Hunter and
Millson 1964). Nowadays, most of the chemical procedures that aim to inactivate
the prion protein are based on the method developed by Kimberlin and
collaborators (1983). This procedure consists of treatment with 20,000 parts per
million free chlorine solution, for a minimum of one hour, of all surfaces that
need to be sterilised (in laboratories, lambing pens, slaughterhouses, and so
on). Despite this, veterinarians and farmers may still ask a range of questions,
such as ‘Is there an official procedure published somewhere?’ and ‘Is there an
international organisation which recommends and defines the exact method of
scrapie decontamination that must be applied?’
From a European perspective, it is difficult to find a treatment that could
be applied, especially in relation to the disinfection of surfaces in lambing
pens of affected flocks. A 999/2001 EU regulation on controlling spongiform
encephalopathies (European Parliament and Council 2001) did not specify a
particular decontamination measure to be used when an outbreak of scrapie is
diagnosed. There is only a brief recommendation in Annex VII concerning the
control and eradication of transmissible spongiform encephalopathies (TSE s).
Chapter B of the regulation explains the measures that must be applied if
new caprine animals are to be introduced to a holding where a scrapie outbreak
has previously been diagnosed. In that case, the statement indicates that
caprine animals can be introduced ‘provided that a cleaning and disinfection of
all animal housing on the premises has been carried out following destocking’.
Issues around cleaning and disinfection are common in prion prevention
recommendations, but relevant authorities, veterinarians and farmers may have
difficulties in finding the specific protocol which applies. The European Food
and Safety Authority (EFSA ) published a detailed report about the efficacy of
certain biocides, such as sodium hydroxide, sodium hypochlorite, guanidine and
even a formulation of copper or iron metal ions in combination with hydrogen
peroxide, against prions (EFSA 2009). The report was based on scientific
evidence (Fichet and others 2004, Lemmer and others 2004, Gao and others 2006,
Solassol and others 2006) but unfortunately the decontamination measures were
not assessed under outbreak conditions.
The EFSA Panel on Biological Hazards recently published its conclusions on
the scrapie situation in the EU after 10 years of monitoring and control of the
disease in sheep and goats (EFSA 2014), and one of the most interesting findings
was the Icelandic experience regarding the effect of disinfection in scrapie
control. The Icelandic plan consisted of: culling scrapie-affected sheep or the
whole flock in newly diagnosed outbreaks; deep cleaning and disinfection of
stables, sheds, barns and equipment with high pressure washing followed by
cleaning with 500 parts per million of hypochlorite; drying and treatment with
300 ppm of iodophor; and restocking was not permitted for at least two years.
Even when all of these measures were implemented, scrapie recurred on several
farms, indicating that the infectious agent survived for years in the
environment, even as many as 16 years after restocking (Georgsson and others
2006).
In the rest of the countries considered in the EFSA (2014) report,
recommendations for disinfection measures were not specifically defined at the
government level. In the report, the only recommendation that is made for sheep
is repopulation with sheep with scrapie-resistant genotypes. This reduces the
risk of scrapie recurrence but it is difficult to know its effect on the
infection.
Until the EFSA was established (in May 2003), scientific opinions about TSE
s were provided by the Scientific Steering Committee (SSC) of the EC, whose
advice regarding inactivation procedures focused on treating animal waste at
high temperatures (150°C for three hours) and high pressure alkaline hydrolysis
(SSC 2003). At the same time, the TSE Risk Management Subgroup of the Advisory
Committee on Dangerous Pathogens (ACDP) in the UK published guidance on safe
working and the prevention of TSE infection. Annex C of the ACDP report
established that sodium hypochlorite was considered to be effective, but only if
20,000 ppm of available chlorine was present for at least one hour, which has
practical limitations such as the release of chlorine gas, corrosion,
incompatibility with formaldehyde, alcohols and acids, rapid inactivation of its
active chemicals and the stability of dilutions (ACDP 2009).
In an international context, the World Organisation for Animal Health (OIE)
does not recommend a specific disinfection protocol for prion agents in its
Terrestrial Code or Manual. Chapter 4.13 of the Terrestrial Code, General
recommendations on disinfection and disinsection (OIE 2014), focuses on
foot-and-mouth disease virus, mycobacteria and Bacillus anthracis, but not on
prion disinfection. Nevertheless, the last update published by the OIE on bovine
spongiform encephalopathy (OIE 2012) indicates that few effective
decontamination techniques are available to inactivate the agent on surfaces,
and recommends the removal of all organic material and the use of sodium
hydroxide, or a sodium hypochlorite solution containing 2 per cent available
chlorine, for more than one hour at 20ºC.
The World Health Organization outlines guidelines for the control of TSE s,
and also emphasises the importance of mechanically cleaning surfaces before
disinfection with sodium hydroxide or sodium hypochlorite for one hour (WHO
1999).
Finally, the relevant agencies in both Canada and the USA suggest that the
best treatments for surfaces potentially contaminated with prions are sodium
hydroxide or sodium hypochlorite at 20,000 ppm. This is a 2 per cent solution,
while most commercial household bleaches contain 5.25 per cent sodium
hypochlorite. It is therefore recommended to dilute one part 5.25 per cent
bleach with 1.5 parts water (CDC 2009, Canadian Food Inspection Agency 2013).
So what should we do about disinfection against prions? First, it is
suggested that a single protocol be created by international authorities to
homogenise inactivation procedures and enable their application in all
scrapie-affected countries. Sodium hypochlorite with 20,000 ppm of available
chlorine seems to be the procedure used in most countries, as noted in a paper
summarised on p 99 of this issue of Veterinary Record (Hawkins and others 2015).
But are we totally sure of its effectiveness as a preventive measure in a
scrapie outbreak? Would an in-depth study of the recurrence of scrapie disease
be needed?
What we can conclude is that, if we want to fight prion diseases, and
specifically classical scrapie, we must focus on the accuracy of diagnosis,
monitoring and surveillance; appropriate animal identification and control of
movements; and, in the end, have homogeneous and suitable protocols to
decontaminate and disinfect lambing barns, sheds and equipment available to
veterinarians and farmers. Finally, further investigations into the resistance
of prion proteins in the diversity of environmental surfaces are required.
References
snip...
98 | Veterinary Record | January 24, 2015
*** Infectious agent of sheep scrapie may persist in the environment for at
least 16 years ***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
Persistence of ovine scrapie infectivity in a farm environment following
cleaning and decontamination
Steve A. C. Hawkins, MIBiol, Pathology Department1, Hugh A. Simmons, BVSc
MRCVS, MBA, MA Animal Services Unit1, Kevin C. Gough, BSc, PhD2 and Ben C.
Maddison, BSc, PhD3 + Author Affiliations
1Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey
KT15 3NB, UK 2School of Veterinary Medicine and Science, The University of
Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK 3ADAS
UK, School of Veterinary Medicine and Science, The University of Nottingham,
Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK E-mail for
correspondence: ben.maddison@adas.co.uk Abstract Scrapie of sheep/goats and
chronic wasting disease of deer/elk are contagious prion diseases where
environmental reservoirs are directly implicated in the transmission of disease.
In this study, the effectiveness of recommended scrapie farm decontamination
regimens was evaluated by a sheep bioassay using buildings naturally
contaminated with scrapie. Pens within a farm building were treated with either
20,000 parts per million free chorine solution for one hour or were treated with
the same but were followed by painting and full re-galvanisation or replacement
of metalwork within the pen. Scrapie susceptible lambs of the PRNP genotype
VRQ/VRQ were reared within these pens and their scrapie status was monitored by
recto-anal mucosa-associated lymphoid tissue. All animals became infected over
an 18-month period, even in the pen that had been subject to the most stringent
decontamination process. These data suggest that recommended current guidelines
for the decontamination of farm buildings following outbreaks of scrapie do
little to reduce the titre of infectious scrapie material and that environmental
recontamination could also be an issue associated with these premises.
SNIP...
Discussion
Thorough pressure washing of a pen had no effect on the amount of
bioavailable scrapie infectivity (pen B). The routine removal of prions from
surfaces within a laboratory setting is treatment for a minimum of one hour with
20,000 ppm free chlorine, a method originally based on the use of brain
macerates from infected rodents to evaluate the effectiveness of decontamination
(Kimberlin and others 1983). Further studies have also investigated the
effectiveness of hypochlorite disinfection of metal surfaces to simulate the
decontamination of surgical devices within a hospital setting. Such treatments
with hypochlorite solution were able to reduce infectivity by 5.5 logs to lower
than the sensitivity of the bioassay used (Lemmer and others 2004). Analogous
treatment of the pen surfaces did not effectively remove the levels of scrapie
infectivity over that of the control pens, indicating that this method of
decontamination is not effective within a farm setting. This may be due to the
high level of biological matrix that is present upon surfaces within the farm
environment, which may reduce the amount of free chlorine available to
inactivate any infectious prion. Remarkably 1/5 sheep introduced into pen D had
also became scrapie positive within nine months, with all animals in this pen
being RAMALT positive by 18 months of age. Pen D was no further away from the
control pen (pen A) than any of the other pens within this barn. Localised hot
spots of infectivity may be present within scrapie-contaminated environments,
but it is unlikely that pen D area had an amount of scrapie contamination that
was significantly different than the other areas within this building.
Similarly, there were no differences in how the biosecurity of pen D was
maintained, or how this pen was ventilated compared with the other pens. This
observation, perhaps, indicates the slower kinetics of disease uptake within
this pen and is consistent with a more thorough prion removal and
recontamination. These observations may also account for the presence of
inadvertent scrapie cases within other studies, where despite stringent
biosecurity, control animals have become scrapie positive during challenge
studies using barns that also housed scrapie-affected animals (Ryder and others
2009).
***The bioassay data indicate that the exposure of the sheep to a farm
environment after decontamination efforts thought to be effective in removing
scrapie is sufficient for the animals to become infected with scrapie. The main
exposure routes within this scenario are likely to be via the oral route, during
feeding and drinking, and respiratory and conjunctival routes. It has been
demonstrated that scrapie infectivity can be efficiently transmitted via the
nasal route in sheep (Hamir and others 2008), as is the case for CWD in both
murine models and in white-tailed deer (Denkers and others 2010, 2013).
Recently, it has also been demonstrated that CWD prions presented as dust
when bound to the soil mineral montmorillonite can be infectious via the nasal
route (Nichols and others 2013). When considering pens C and D, the actual
source of the infectious agent in the pens is not known, it is possible that
biologically relevant levels of prion survive on surfaces during the
decontamination regimen (pen C). With the use of galvanising and painting (pen
D) covering and sealing the surface of the pen, it is possible that scrapie
material recontaminated the pens by the movement of infectious prions contained
within dusts originating from other parts of the barn that were not
decontaminated or from other areas of the farm.
Given that scrapie prions are widespread on the surfaces of affected farms
(Maddison and others 2010a), irrespective of the source of the infectious prions
in the pens, this study clearly highlights the difficulties that are faced with
the effective removal of environmentally associated scrapie infectivity. This is
likely to be paralleled in CWD which shows strong similarities to scrapie in
terms of both the dissemination of prions into the environment and the facile
mode of disease transmission. These data further contribute to the understanding
that prion diseases can be highly transmissible between susceptible individuals
not just by direct contact but through highly stable environmental reservoirs
that are refractory to decontamination.
The presence of these environmentally associated prions in farm buildings
make the control of these diseases a considerable challenge, especially in
animal species such as goats where there is lack of genetic resistance to
scrapie and, therefore, no scope to re-stock farms with animals that are
resistant to scrapie.
Scrapie Sheep Goats Transmissible spongiform encephalopathies (TSE)
Accepted October 12, 2014. Published Online First 31 October 2014
Monday, November 3, 2014
Persistence of ovine scrapie infectivity in a farm environment following
cleaning and decontamination
PPo3-22:
Detection of Environmentally Associated PrPSc on a Farm with Endemic
Scrapie
Ben C. Maddison,1 Claire A. Baker,1 Helen C. Rees,1 Linda A. Terry,2 Leigh
Thorne,2 Susan J. Belworthy2 and Kevin C. Gough3 1ADAS-UK LTD; Department of
Biology; University of Leicester; Leicester, UK; 2Veterinary Laboratories
Agency; Surry, KT UK; 3Department of Veterinary Medicine and Science; University
of Nottingham; Sutton Bonington, Loughborough UK
Key words: scrapie, evironmental persistence, sPMCA
Ovine scrapie shows considerable horizontal transmission, yet the routes of
transmission and specifically the role of fomites in transmission remain poorly
defined. Here we present biochemical data demonstrating that on a
scrapie-affected sheep farm, scrapie prion contamination is widespread. It was
anticipated at the outset that if prions contaminate the environment that they
would be there at extremely low levels, as such the most sensitive method
available for the detection of PrPSc, serial Protein Misfolding Cyclic
Amplification (sPMCA), was used in this study. We investigated the distribution
of environmental scrapie prions by applying ovine sPMCA to samples taken from a
range of surfaces that were accessible to animals and could be collected by use
of a wetted foam swab. Prion was amplified by sPMCA from a number of these
environmental swab samples including those taken from metal, plastic and wooden
surfaces, both in the indoor and outdoor environment. At the time of sampling
there had been no sheep contact with these areas for at least 20 days prior to
sampling indicating that prions persist for at least this duration in the
environment. These data implicate inanimate objects as environmental reservoirs
of prion infectivity which are likely to contribute to disease transmission.
>>>We report here the identification and characterization of 2
natural classic scrapie cases in sheep of the ARR/ARR genotype, which are
clearly different from BSE and atypical scrapie.
Classic Scrapie in Sheep with the ARR/ARR Prion Genotype in Germany and
France
Martin H. Groschup,*1 Caroline Lacroux,†1 Anne Buschmann,* Gesine Lühken,‡
Jacinthe Mathey,† Martin Eiden,* Séverine Lugan,† Christine Hoffmann,* Juan
Carlos Espinosa,§ Thierry Baron,¶ Juan Maria Torres,§ Georg Erhardt,‡ and
Olivier Andreoletti†
In the past, natural scrapie and bovine spongiform encephalopathy (BSE)
infections have essentially not been diagnosed in sheep homozygous for the
A136R154R171 haplotype of the prion protein. This genotype was therefore assumed
to confer resistance to BSE and classic scrapie under natural exposure
conditions. Hence, to exclude prions from the human food chain, massive breeding
efforts have been undertaken in the European Union to amplify this gene. We
report the identifi cation of 2 natural scrapie cases in ARR/ARR sheep that have
biochemical and transmission characteristics similar to cases of classic
scrapie, although the abnormally folded prion protein (PrPSc) was associated
with a lower proteinase-K resistance. PrPSc was clearly distinct from BSE prions
passaged in sheep and from atypical scrapie prions. These findings strongly
support the idea that scrapie prions are a mosaic of agents, which harbor
different biologic properties, rather than a unique entity.
snip...
However, the successful transmission of BSE prions to ARR/ARR sheep showed
that the resistance of this genotype toward the TSE agent was not absolute (11).
Recently, the identification of previously unrecognized so-called atypical
scrapie in sheep of various genotypes, including ARR/ARR, has reinforced this
statement (4).
***We report here the identification and characterization of 2 natural
classic scrapie cases in sheep of the ARR/ARR genotype, which are clearly
different from BSE and atypical scrapie.
snip...
see full text ;
Assessing Transmissible Spongiform Encephalopathy Species Barriers with an
In Vitro Prion Protein Conversion Assay
Christopher J. Johnson1, Christina M. Carlson2, Aaron R. Morawski3, Alyson
Manthei4, Neil R. Cashman5
1USGS National Wildlife Health Center, 2Department of Soil Science,
University of Wisconsin–Madison, 3Laboratory of Immunology, National Institute
of Allergy and Infectious Diseases, National Institutes of Health, 4Merial
Veterinary Scholars Program, School of Veterinary Medicine, University of
Wisconsin–Madison, 5Department of Neurology, University of British Columbia
Summary
Measuring the barrier to the interspecies transmission of prion diseases is
challenging and typically involves animal challenges or biochemical assays.
Here, we present an in vitro prion protein conversion assay with the ability to
predict species barriers.
Date Published: 3/10/2015, Issue 97; doi: 10.3791/52522
Keywords: Medicine, Issue 97, Prion, species barrier, conversion,
immunoblotting, transmissible spongiform encephalopathy, interspecies
transmission Cite this Article
Johnson, C. J., Carlson, C. M., Morawski, A. R., Manthei, A., Cashman, N.
R. Assessing Transmissible Spongiform Encephalopathy Species Barriers with an In
Vitro Prion Protein Conversion Assay. J. Vis. Exp. (97), e52522,
doi:10.3791/52522 (2015). Abstract
Studies to understanding interspecies transmission of transmissible
spongiform encephalopathies (TSEs, prion diseases) are challenging in that they
typically rely upon lengthy and costly in vivo animal challenge studies. A
number of in vitro assays have been developed to aid in measuring prion species
barriers, thereby reducing animal use and providing quicker results than animal
bioassays. Here, we present the protocol for a rapid in vitro prion conversion
assay called the conversion efficiency ratio (CER) assay. In this assay cellular
prion protein (PrPC) from an uninfected host brain is denatured at both pH 7.4
and 3.5 to produce two substrates. When the pH 7.4 substrate is incubated with
TSE agent, the amount of PrPC that converts to a proteinase K (PK)-resistant
state is modulated by the original host’s species barrier to the TSE agent. In
contrast, PrPC in the pH 3.5 substrate is misfolded by any TSE agent. By
comparing the amount of PK-resistant prion protein in the two substrates, an
assessment of the host’s species barrier can be made. We show that the CER assay
correctly predicts known prion species barriers of laboratory mice and, as an
example, show some preliminary results suggesting that bobcats (Lynx rufus) may
be susceptible to white-tailed deer (Odocoileus virginianus) chronic wasting
disease agent.
>>> show some preliminary results suggesting that bobcats (Lynx
rufus) may be susceptible to white-tailed deer (Odocoileus virginianus) chronic
wasting disease agent.
AD.63: Susceptibility of domestic cats to chronic wasting disease
Amy V.Nalls,1 Candace Mathiason,1 Davis Seelig,2 Susan Kraft,1 Kevin
Carnes,1 Kelly Anderson,1 Jeanette Hayes-Klug1 and Edward A. Hoover1
1Colorado State University; Fort Collins, CO USA; 2University of Minnesota;
Saint Paul, MN USA
Domestic and nondomestic cats have been shown to be susceptible to feline
spongiform encephalopathy (FSE), almost certainly caused by consumption of
bovine spongiform encephalopathy (BSE)-contaminated meat. Because domestic and
free-ranging nondomestic felids scavenge cervid carcasses, including those in
areas affected by chronic wasting disease (CWD), we evaluated the susceptibility
of the domestic cat (Felis catus) to CWD infection experimentally. Cohorts of 5
cats each were inoculated either intracerebrally (IC) or orally (PO) with
CWD-infected deer brain. At 40 and 42 mo post-inoculation, two IC-inoculated
cats developed signs consistent with prion disease, including a stilted gait,
weight loss, anorexia, polydipsia, patterned motor behaviors, head and tail
tremors, and ataxia, and progressed to terminal disease within 5 mo. Brains from
these two cats were pooled and inoculated into cohorts of cats by IC, PO, and
intraperitoneal and subcutaneous (IP/SC) routes. Upon subpassage, feline-adapted
CWD (FelCWD) was transmitted to all IC-inoculated cats with a decreased
incubation period of 23 to 27 mo. FelCWD was detected in the brains of all the
symptomatic cats by western blotting and immunohistochemistry and abnormalities
were seen in magnetic resonance imaging, including multifocal T2 fluid
attenuated inversion recovery (FLAIR) signal hyper-intensities, ventricular size
increases, prominent sulci, and white matter tract cavitation. Currently, 3 of 4
IP/SQ and 2 of 4 PO inoculared cats have developed abnormal behavior patterns
consistent with the early stage of feline CWD. These results demonstrate that
CWD can be transmitted and adapted to the domestic cat, thus raising the issue
of potential cervid-to- feline transmission in nature.
www.landesbioscience.com
PO-081: Chronic wasting disease in the cat— Similarities to feline
spongiform encephalopathy (FSE)
PO-081: Chronic wasting disease in the cat— Similarities to feline
spongiform encephalopathy (FSE)
Thursday, May 31, 2012
CHRONIC WASTING DISEASE CWD PRION2012 Aerosol, Inhalation transmission,
Scrapie, cats, species barrier, burial, and more
Monday, August 8, 2011
Susceptibility of Domestic Cats to CWD Infection
Sunday, August 25, 2013
Prion2013 Chronic Wasting Disease CWD risk factors, humans, domestic cats,
blood, and mother to offspring transmission
Feline Spongiform Encephalopathy (FSE) FSE was first identified in the UK
in 1990. Most cases have been reported in the UK, where the epidemic has been
consistent with that of the BSE epidemic. Some other countries (e.g. Norway,
Liechtenstein and France) have also reported cases.
Most cases have been reported in domestic cats but there have also been
cases in captive exotic cats (e.g. Cheetah, Lion, Asian leopard cat, Ocelot,
Puma and Tiger). The disease is characterised by progressive nervous signs,
including ataxia, hyper-reactivity and behavioural changes and is fatal.
The chemical and biological properties of the infectious agent are
identical to those of the BSE and vCJD agents. These findings support the
hypothesis that the FSE epidemic resulted from the consumption of food
contaminated with the BSE agent.
The FSE epidemic has declined as a result of tight controls on the disposal
of specified risk material and other animal by-products.
References: Leggett, M.M. et al.(1990) A spongiform encephalopathy in a
cat. Veterinary Record. 127. 586-588
Synge, B.A. et al. (1991) Spongiform encephalopathy in a Scottish cat.
Veterinary Record. 129. 320
Wyatt, J. M. et al. (1991) Naturally occurring scrapie-like spongiform
encephalopathy in five domestic cats. Veterinary Record. 129. 233.
Gruffydd-Jones, T. J.et al.. (1991) Feline spongiform encephalopathy. J.
Small Animal Practice. 33. 471-476.
Pearson, G. R. et al. (1992) Feline spongiform encephalopathy: fibril and
PrP studies. Veterinary Record. 131. 307-310.
Willoughby, K. et al. (1992) Spongiform encephalopathy in a captive puma
(Felis concolor). Veterinary Record. 131. 431-434.
Fraser, H. et al. (1994) Transmission of feline spongiform encephalopathy
to mice. Veterinary Record 134. 449.
Bratberg, B. et al. (1995) Feline spongiform encephalopathy in a cat in
Norway. Veterinary Record 136. 444
Baron, T. et al. (1997) Spongiform encephalopathy in an imported cheetah in
France. Veterinary Record 141. 270-271
Zanusso, G et al. (1998) Simultaneous occurrence of spongiform
encephalopathy in a man and his cat in Italy. Lancet, V352, N9134, OCT 3, Pp
1116-1117.
Ryder, S.J. et al. (2001) Inconsistent detection of PrP in extraneural
tissues of cats with feline spongiform encephalopathy. Veterinary Record 146.
437-441
Kelly, D.F. et al. (2005) Neuropathological findings in cats with
clinically suspect but histologically unconfirmed feline spongiform
encephalopathy. Veterinary Record 156. 472-477.
3 further cheetah cases have occured, plus 1 lion, plus all the primates,
and 20 additional house cats. Nothing has been published on any of these UK
cases either. One supposes the problem here with publishing is that many
unpublished cases were _born_ long after the feed "ban". Caught between a rock
and a hard place: leaky ban or horizontal transmission (or both).
Evidence That Transmissible Mink Encephalopathy Results from Feeding
Infected Cattle
Over the next 8-10 weeks, approximately 40% of all the adult mink on the
farm died from TME.
snip...
The rancher was a ''dead stock'' feeder using mostly (>95%) downer or
dead dairy cattle...
In Confidence - Perceptions of unconventional slow virus diseases of
animals in the USA - APRIL-MAY 1989 - G A H Wells
3. Prof. A. Robertson gave a brief account of BSE. The US approach was to
accord it a very low profile indeed. Dr. A Thiermann showed the picture in the
''Independent'' with cattle being incinerated and thought this was a fanatical
incident to be avoided in the US at all costs. ...
Wednesday, September 23, 2015
NIH Availability for Licensing AGENCY: [FR Doc. 2015–24117 Filed 9–22–15;
8:45 am] Detection and Discrimination of Classical and Atypical L-Type BSE
Strains by RT-QuIC
Thursday, October 1, 2015
H-type bovine spongiform encephalopathy associated with E211K prion protein
polymorphism: clinical and pathologic features in wild-type and E211K cattle
following intracranial inoculation
Master Obi-Wan Kenobi, Kemosabe...THIS IS NOT GOOD
GOOSE!...grasshopper...tonto...tss
Wednesday, May 27, 2015
BSE Case Associated with Prion Protein Gene Mutation
spontaneous atypical BSE ???
don’t let anyone fool you. spontaneous TSE prion disease is a hoax in
natural cases, never proven.
all one has to do is look at France. France is having one hell of an
epidemic of atypical BSE, probably why they stopped testing for BSE, problem
solved $$$ same as the USA, that’s why they stopped testing for BSE mad cow
disease in numbers they could find any with, after those atypical BSE cases
started showing up. shut down the testing to numbers set up by OIE that are so
low, you could only by accident find a case of BSE aka mad cow disease. and this
brilliant idea by the WHO et al, to change the name of mad cow disease, thinking
that might change things is preposterous. it’s all about money now folks, when
the OIE, USDA and everyone else went along and made the TSE prion disease aka
mad cow type disease a legal trading commodity by the BSE MRR policy, I would
say everyone bit off more then they can chew, and they will just have to digest
those TSE Prions coming from North America, and like it, and just prey you don’t
get a mad cow type disease i.e. Transmissible Spongiform Encephalopathy TSE
prion disease in the decades to come, and or pass it to some other poor soul via
the iatrogenic medical surgical tissue friendly fire mode of transmission i.e.
second hand transmission. it’s real folks, just not documented much, due to lack
of trace back efforts. all iatrogenic cjd is, is sporadic cjd, until the
iatrogenic event is tracked down and documented, and put into the academic and
public domain, which very seldom happens. ...
As of December 2011, around 60 atypical BSE cases have currently been
reported in 13 countries, *** with over one third in France.
***atypical spontaneous BSE in France LOL***
FRANCE STOPS TESTING FOR MAD COW DISEASE BSE, and here’s why, to many
spontaneous events of mad cow disease $$$
***so 20 cases of atypical BSE in France, compared to the remaining 40
cases in the remaining 12 Countries, divided by the remaining 12 Countries,
about 3+ cases per country, besides Frances 20 cases. you cannot explain this
away with any spontaneous BSe. ...TSS
Sunday, October 5, 2014
France stops BSE testing for Mad Cow Disease
Saturday, September 12, 2015
The Canadian Management of Bovine Spongiform Encephalopathy in Historical
and Scientific Perspective, 1990-2014
>>>We propose that Canadian policies largely ignored the implicit
medical nature of BSE, treating it as a purely agricultural and veterinary
issue. In this way, policies to protect Canadians were often delayed and
incomplete, in a manner disturbingly reminiscent of Britain’s failed management
of BSE. Despite assurances to the contrary, it is premature to conclude that BSE
(and with it the risk of variant Creutzfeldt-Jakob disease) is a thing of
Canada’s past: BSE remains very much an issue in Canada’s present.
<<<
Thursday, September 10, 2015
25th Meeting of the Transmissible Spongiform Encephalopathies Advisory
Committee Food and Drug Administration Silver Spring, Maryland June 1, 2015
U.S.A. 50 STATE BSE MAD COW CONFERENCE CALL Jan. 9, 2001
Monday, October 26, 2015
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED
VIOLATIONS OFFICIAL ACTION INDICATED OIA UPDATE October 2015
.150: Zoonotic potential of L-type BSE prions: A new prion disease in
humans?
Emilie Jaumain,1 Stéphane Haïk,2 Isabelle Quadrio,3 Laetitia Herzog,1
Fabienne Reine,1 Armand Perret-Liaudet,3 Human Rezaei,1 Hubert Laude,1 Jean-Luc
Vilotte,4 and Vincent Béringue1 1INR A (Institut National de la Recherche
Agronomique); UR892; Virologie Immunologie Moléculaires; Jouy-en-Josas, France;
2IN SERM; Equipe maladie d’Alzheimer et maladies à Prions; CRicm; UMRS 1127; CNR
S; UPMC. R.; ICM, Hôpital de la Salpêtrière; Paris, France; 3Neurobiologie, CMRR
, Gériatrie, Hospices Civils de Lyon, Université Lyon 1-CNR S UMR5292-IN SERM
U1028; Lyon, France; 3INR A; UMR1313; Génétique Animale et Biologie Intégrative;
Jouy-en-Josas, France
Two novel prion strains, referred to as BSE-L and BSE-H, have been
recognized in bovines through active prion surveillance programs, both being
distinct from the epizootic, ‘classical’, BSE strain (C-BSE). Both H and L-types
have been detected worldwide as rare cases occurring in aged animals. Like C-BSE
prions, H- and L-types prions can propagate with relative ease in foreign
species or in transgenic mouse lines expressing heterologous PrP sequences. A
prion exhibiting biological properties similar to C-BSE agent sometimes emerged
from these cross-species transmissions. Previously, L-type prions were shown to
transmit to transgenic mice expressing human PrP with methionine at codon 129
with higher efficacy than C-BSE prions. Here, we examined whether L-type prions
propagate without any apparent transmission barrier in these mice and whether
such ‘humanised’ L-type prions share biological properties with CJD prions.
L-type prions and a panel of human CJD cases with various genotypes at codon 129
and electrophoretic PrPres signatures were serially transmitted by intracerebral
route to human PrP mice. The biological phenotypes induced by these agents were
compared by all the standard methods currently used to distinguish between prion
strains. At each passage, L-type prions were also transmitted back to bovine PrP
mice to assess whether the agent has evolved upon passaging on the human PrP
sequence. L-type prions transmitted to human PrP mice at 100% attack rate,
without notable alteration in the mean incubation times over 5 passages. At each
passage, ‘humanized’ L-type prions were able to transmit back to bovine PrP
transgenic mice without apparent transmission barrier, as based on the survival
time and the restoration of a L-type BSE phenotype. Comparison of mean
incubation times on primary and subsequent passages in human PrP mice showed no
overlap between L-type and sporadic CJD agents. While the electrophoretic
signature and regional distribution of PrPres in L-type diseased mouse brains
resembled that seen after transmission of MM2 CJD strain type, both agents
exhibited distinct resistance of the associated PrPres molecules to protease
denaturation.
In summary, L-type prions can be passaged on the human PrP sequence without
any obvious transmission barrier. The phenotype obtained differs from the
classical CJD prion types known so far. Careful extrapolation would suggest that
the zoonotic transmission of this agent could establish a new prion disease type
in humans.
========Prion2013==========
2012 ATYPICAL L-TYPE BASE BSE TSE PRION CALIFORNIA ‘confirmed’ Saturday,
August 4, 2012
*** Final Feed Investigation Summary - California BSE Case - July 2012
31 Jan 2015 at 20:14 GMT
*** Ruminant feed ban for cervids in the United States? ***
Singeltary et al
31 Jan 2015 at 20:14 GMT
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics
of BSE in Canada Singeltary reply ;
*** It also suggests a similar cause or source for atypical BSE in these
countries. ***
Discussion: The C, L and H type BSE cases in Canada exhibit molecular
characteristics similar to those described for classical and atypical BSE cases
from Europe and Japan.
*** This supports the theory that the importation of BSE contaminated
feedstuff is the source of C-type BSE in Canada.
*** It also suggests a similar cause or source for atypical BSE in these
countries. ***
see page 176 of 201 pages...tss
CONCLUSIONS:
Characterisation of the causal agents of disease resulting from exposure of
cattle to naturally occurring scrapie agents sourced in Great Britain did not
reveal evidence of classical or atypical BSE, but did identify two distinct
previously recognised strains of scrapie. Although scrapie was still
recognizable upon cattle passage there were irreconcilable discrepancies between
the results of biological strain typing approaches and molecular profiling
methods, suggesting that the latter may not be appropriate for the
identification and differentiation of atypical, particularly L-type, BSE agents
from cattle experimentally infected with a potential mixture of classical
scrapie strains from sheep sources.
PMID: 26205536 [PubMed - in process]
Conclusions
Two different disease phenotypes were produced after intracerebral
inoculation of cattle with scrapie brain pools sourced pre-1975 and post-1990 in
GB, which were not readily explained by any differences in PrP genotype of the
cattle. Based on pathological and molecular characteristics and biological
characterisation in bank voles and transgenic mice there was no clear evidence
of an agent derived from the cattle resembling classical or atypical forms of
BSE. Transmissions in bank voles identified previously isolated scrapie strains
and some similarities to the experimental isolate CH1641. Contrary to the
transmission results in rodents, the results for the molecular techniques, which
have been adopted for the detection of atypical BSE cases, suggest that they may
not be appropriate for differentiating WB profiles in cattle following infection
from an ovine scrapie source.
Monday, July 20, 2015
Does the Presence of Scrapie Affect the Ability of Current Statutory
Discriminatory Tests To Detect the Presence of Bovine Spongiform Encephalopathy?
Wednesday, July 29, 2015
Further characterisation of transmissible spongiform encephalopathy
phenotypes after inoculation of cattle with two temporally separated sources of
sheep scrapie from Great Britain
IBNC Tauopathy or TSE Prion disease, it appears, no one is sure
Singeltary et al
Posted by flounder on 03 Jul 2015 at 16:53 GMT
Monday, October 26, 2015
FDA PART 589 -- SUBSTANCES PROHIBITED FROM USE IN ANIMAL FOOD OR FEED
VIOLATIONS OFFICIAL ACTION INDICATED OIA UPDATE October 2015
Thursday, July 24, 2014
Protocol for further laboratory investigations into the distribution of
infectivity of Atypical BSE SCIENTIFIC REPORT OF EFSA
Wednesday, October 30, 2013
SPECIFIED RISK MATERIAL (SRM) CONTROL VERIFICATION TASK FSIS NOTICE 70-13
10/30/13
Review Methods for Differentiating Prion Types in Food-Producing Animals
Kevin C. Gough 1,*, Helen C. Rees 2, Sarah E. Ives 1 and Ben C. Maddison 2
1 School of Veterinary Medicine and Science, The University of Nottingham,
Sutton Bonington Campus, College Road, Sutton Bonington, Leicestershire LE12
5RD, UK; E-Mail: svysei@exmail.nottingham.ac.uk 2 ADAS UK, School of Veterinary
Medicine and Science, The University of Nottingham, Sutton Bonington Campus,
College Road, Sutton Bonington, Leicestershire LE12 5RD, UK; E-Mails:
Helen.Rees@adas.co.uk (H.C.R.); Ben.Maddison@adas.co.uk (B.C.M.) * Author to
whom correspondence should be addressed; E-Mail: Kevin.Gough@nottingham.ac.uk;
Tel.: +44-115-951-6272; Fax: +44-115-951-6440. Academic Editor: Christian D.
Doerig Received: 31 August 2015 / Accepted: 4 November 2015 / Published: 13
November 2015
Abstract: Prions are an enigma amongst infectious disease agents as they
lack a genome yet confer specific pathologies thought to be dictated mainly, if
not solely, by the conformation of the disease form of the prion protein
(PrPSc). Prion diseases affect humans and animals, the latter including the
food-producing ruminant species cattle, sheep, goats and deer. Importantly, it
has been shown that the disease agent of bovine spongiform encephalopathy (BSE)
is zoonotic, causing variant Creutzfeldt Jakob disease (vCJD) in humans. Current
diagnostic tests can distinguish different prion types and in foodproducing
animals these focus on the differentiation of BSE from the non-zoonotic agents.
Whilst BSE cases are now rare, atypical forms of both scrapie and BSE have been
reported, as well as two types of chronic wasting disease (CWD) in cervids.
Typing of animal prion isolates remains an important aspect of prion diagnosis
and is now becoming more focused on identifying the range of prion types that
are present in food-producing animals and also developing tests that can screen
for emerging, novel prion diseases. Here, we review prion typing methodologies
in light of current and emerging prion types in food-producing animals.
snip...
8. Conclusions and Future Perspectives Whilst the cases of BSE in ruminants
is now very low and the associated concern for the contamination of the human
food chain with the zoonotic BSE agent has eased, there are still concerns
surrounding the exposure of humans to prions from food-producing animals. The
more recent description of atypical/Nor98 scrapie in goats/sheep and atypical
bovine BSE as well as the discovery of two distinct types of CWD all raise the
possibility that further types of prions are circulating in ruminants that are
not detected and/or defined by current assay methods. An additional concern is
that novel types may emerge in these animals. One diagnostic challenge in prion
biology is to develop and apply prion typing tests to fully elucidate the range
of existing prion types in ruminants and to monitor for the emergence of novel
types. This is a significant challenge as it is unknown what molecular and
pathological differences any novel type will have compared to those already
described. Therefore, assays that have a wide range of distinct measurements
that describe a PrPSc type or in vivo pathology will be best suited for
diagnosing new prion types...
snip...see full text ;
CWD
Decision on listing (new CH)
TAHSC & SCAD & AHG
Pending AHG
The Director General also expressed his concerns on the impact of atypical
BSE in disease surveillance notification and status recognition and requested
the Commission to continue its work, in coordination with the Terrestrial Animal
Health Standard Commission (Code Commission), to address this issue.
http://www.oie.int/fileadmin/Home/eng/Internationa_Standard_Setting/docs/pdf/SCAD/A_SCAD_Feb2015.pdf
applications from Member Countries for the recognition of BSE risk status
of Member Countries. The ad hoc Group also amended Chapter 11.4. on bovine
spongiform encephalopathy to consider the impact of atypical BSE on the
countries’ BSE risk status and to clarify that the requirements for risk
classification only relates to classical BSE.
The Commission recommended that the Assembly recognise the following Member
Countries as having a negligible BSE risk: Cyprus, Czech Republic, France,
Ireland, Liechtenstein and Switzerland.
The Commission also agreed with the conclusion of the ad hoc Group
regarding the non-compliance of the application of a Member Country.
In addition the Commission discussed in depth the application from one
Member Country and concurred with the ad hoc Group that a mission to the country
would be recommended to come to an informed decision.
The Commission agreed with the modifications proposed by the ad hoc Group
on Chapter 11.4. on BSE to differentiate atypical from classical BSE and to
consider the impact of atypical BSE on BSE risk status and on public
health.
The Commission acknowledged with appreciation the work done by the ad hoc
Group to adapt the surveillance system to the current BSE incidence considering
the role of both atypical and classical BSE. However, although scientifically
robust, this model gave more weight to the surveillance in older animals and
allocated higher surveillance points to those countries that focus their
surveillance to aged animals. It appeared not to be appropriate to some of OIE
Member Countries already recognised as having a controlled or negligible BSE
risk status. The Commission concluded that the proposed modification could not
be considered at this stage for inclusion in the Terrestrial Code.
The Commission suggested that the Biological Standard Commission consider a
revision of the BSE chapter of the Terrestrial Manual to include the description
of the available tests able to discriminate atypical from classical BSE.
The Commission took note of the recommendation of the ad hoc Group
regarding terminology and agreed that defining technical terms could be
beneficial and that it could be done at the next ad hoc Group meeting when the
revision of the questionnaire would be on the agenda. However, the Commission
did not consider that the proposal to translate some technical terms into more
languages other than the OIE official languages was a priority.
The amended chapter and the report of the ad hoc Group were provided to the
Code Commission for further processing.
The endorsed report of the ad hoc Group is attached as Annex 12.
Scientific Commission/February 2015
snip...
Annex 12
Original: English
November 2014
REPORT OF THE MEETING OF THE OIE AD HOC GROUP
ON BOVINE SPONGIFORM ENCEPHALOPATHY RISK STATUS EVALUATION OF MEMBER
COUNTRIES
Paris, 25-27 November 2014
_______
A meeting of the ad hoc Group on bovine spongiform encephalopathy (BSE)
risk status evaluation of Member Countries (hereafter the Group) was held at the
OIE Headquarters from 25 to 27 November 2014.
1. Opening
On behalf of Dr Bernard Vallat, Director General of the OIE, Dr Brian
Evans, the OIE Deputy Director General and Head of Scientific and Technical
Department, welcomed and thanked the experts for their commitment towards the
OIE and for personal and professional time invested to evaluate the
dossiers.
Dr Evans ensured the Group that the challenges met to assess the
applications were fully recognised and that, to increasingly take on board the
difficulty of the assessment, the OIE Director General supported the Scientific
Commission for Animal Diseases proposing that more in-country missions be
conducted to verify the information provided in the written dossiers.
He mentioned that three missions to Member Countries would be planned
before the upcoming General Session, reflecting the considerable involvement of
the Scientific Commission at the national and regional level to assist and meet
the expectations of Member Countries. He also emphasised the importance of
accountability and that the procedures should be consistently applied in a
transparent manner and well-grounded with the Resolutions adopted by the World
Assembly of Delegates.
Dr Evans informed the Group that a series of workshops would be conducted
in the next two years in each of the OIE regions in order to provide training
for Member Countries on the key elements to consider when preparing a dossier
for official recognition of disease or risk status. The Group was informed that
the pilot workshop would be conducted in the Americas focussing on BSE and
classical swine fever. Therefore, the support and advice of the Group in the
identification of problematic areas in the dossiers was requested.
Dr Evans noted that the Group would have to consider the global decline of
BSE, the relative higher importance of atypical BSE, the human health impact and
the cost of surveillance when revising the current BSE chapter of the
Terrestrial Animal Health Code (Terrestrial Code).
He finally introduced Dr Kazutoshi Matsuo, who recently joined the
Scientific and Technical Department. He would be engaged in the activities
related to official status recognition.
2. Adoption of the agenda and appointment of chairperson and
rapporteur
Dr Dagmar Heim was appointed Chair and Dr Martial Plantady acted as
rapporteur with the support of the OIE Secretariat. The Group endorsed the
proposed agenda. The agenda and list of participants are provided as Appendices
I and II, respectively.
Annex 12 (contd) AHG BSE Risk Status Evaluation of Member
Countries/November 2014
108 Scientific Commission/February 2015
3. Evaluation of requests from Member Countries for the evaluation of BSE
risk status
Preliminary analyses were conducted by two members of the Group for each
dossier (as allocated by the OIE Headquarters) prior to the meeting. The experts
presented their key findings to the plenary, which proceeded with in-depth
discussion, dossier by dossier, on the applicant Member Countries’ compliance
with the provisions on BSE risk status in the Terrestrial Code. Where necessary,
messages were sent electronically to the applicants requesting additional
information. All Member Countries contacted provided the requested information
to the Group on time.
Dr John Kellar could not attend the meeting but provided his feed-back on
the dossiers and on the other topics of the agenda, before and during the
meeting, through electronic correspondence. Furthermore, he participated in
parts of the discussion via teleconference on 26 November 2014.
3.1. Cyprus
The Group recalled that in July 2007 the OIE received a dossier from Cyprus
to evaluate the BSE risk status of its cattle population in accordance with the
Terrestrial Code. The recommendation of the Group at that time was that Cyprus
should be regarded as having met the requirements for recognition as complying
with the BSE Chapter of the Terrestrial Code as ‘controlled BSE risk’.
In September 2014, Cyprus submitted a dossier seeking a negligible BSE risk
status. The Group agreed that the submission conformed to the guidelines
circulated for Member Countries wishing to make a formal evaluation of their BSE
risk status according to the requirements of the Terrestrial Code.
Points specifically noted by the Group were summarised in the following
discussion.
a) Section 1: Risk Assessment — Article 11.4.2. point 1
Risk assessment for entry of the BSE agent
The Group considered that the conclusion of the entry assessment was that
the risk that the BSE agent could have entered Cyprus during the interval
covered by the assessment, although very low, was not negligible.
Risk of recycling and amplification of the BSE agent
The Group considered that the conclusion of the exposure assessment was
that there was a negligible risk of recycling and amplification of the BSE agent
if it were present in Cyprus’s cattle population during the interval covered by
the assessment.
b) Surveillance according to Articles 11.4.20.-11.4.22.
The Group noted that the surveillance undertaken exceeded the minimum
requirements of type B surveillance according to Article 11.4.22. on
surveillance for BSE in the Terrestrial Code. 8,715 surveillance points were
collected, compared to a minimal requirement of 3,300 for an adult cattle
population of 31,918 over two years of age.
c) Other requirements — Article 11.4.2. points 2–4
Awareness programme
The Group noted that the awareness programme started in 1991 and met the
requirements of the Terrestrial Code.
Compulsory notification and investigation
The Group noted that BSE was declared a notifiable disease under relevant
legislation since 1990 and determined that the system for compulsory
notification and investigation met the requirements of the Terrestrial
Code.
Laboratory examination
The Group determined that the arrangements for laboratory examination met
the requirements of the Manual of Diagnostic Tests and Vaccines for Terrestrial
Animals (Terrestrial Manual).
AHG BSE Risk Status Evaluation of Member Countries/November 2014 Annex 12
(contd)
Scientific Commission/February 2015 109
Appropriate level of control and audit of the feed ban
The Group noted that the appropriate legislation, control and audit of the
proper implementation of the feed ban had been in force for at least eight
years.
d) BSE history in the country
No BSE case had been recorded in Cyprus.
e) Compliance with conditions for ‘negligible BSE risk’ status - Article
11.4.3.
Based on the information provided, the Group recommended that Cyprus be
regarded as having met the requirements for recognition as complying with the
BSE Chapter of the Terrestrial Code as ‘negligible BSE risk’.
f) Conclusions
Recommended status: ‘Negligible BSE risk’.
3.2. Czech Republic
The Group recalled that in July 2007 the OIE received a dossier from Czech
Republic to evaluate the BSE risk status of its cattle population in accordance
with the Terrestrial Code. The recommendation of the Group at that time was that
the Czech Republic should be regarded as having met the requirements for
recognition as complying with the BSE Chapter of the Terrestrial Code as
‘controlled BSE risk’.
In September 2014, the Czech Republic submitted a dossier seeking a
negligible BSE risk status. The Group agreed that the submission conformed to
the guidelines circulated for Member Countries wishing to make a formal
evaluation of their BSE risk status according to the requirements of the
Terrestrial Code.
The Group requested additional information and received clarification from
the Czech Republic. Points specifically noted by the Group were summarised in
the following discussion.
a) Section 1: Risk Assessment — Article 11.4.2. point 1
Risk assessment for entry of the BSE agent
The Group considered that the conclusion of the entry assessment was that
the risk that the BSE agent could have entered the Czech Republic during the
interval covered by the assessment, although very low, was not negligible.
Risk of recycling and amplification of the BSE agent
The Group considered that the conclusion of the exposure assessment was
that there was a negligible risk of recycling and amplification of the BSE agent
if it were present in Czech Republic’s cattle population during the interval
covered by the assessment.
b) Surveillance according to Articles 11.4.20.-11.4.22.
The Group noted that the surveillance undertaken exceeded the minimum
requirements of type B surveillance according to Article 11.4.22. on
surveillance for BSE in the Terrestrial Code. 207,356 surveillance points were
collected, compared to a minimal requirement of 71,500 for an adult cattle
population of 663,423 over two years of age.
c) Other requirements — Article 11.4.2. points 2–4
Awareness programme
The Group determined that the awareness programme began in 1991 and met the
requirements of the Terrestrial Code.
Annex 12 (contd) AHG BSE Risk Status Evaluation of Member
Countries/November 2014
110 Scientific Commission/February 2015
Compulsory notification and investigation
The Group noted that BSE was declared a notifiable disease under relevant
legislation since 1999 and determined that the system for compulsory
notification and investigation met the requirements of the Terrestrial
Code.
Laboratory examination
The Group determined that the arrangements for laboratory examination met
the requirements of the Terrestrial Manual.
Appropriate level of control and audit of the feed ban
The Group noted that the appropriate legislation, control and audit of the
proper implementation of the feed ban had been in force for at least eight
years.
d) BSE history in the country
The Group noted that the Czech Republic had reported 30 cases of BSE. The
youngest BSE case was born on 8 May 2004, meaning that all indigenous cases
would have been born more than 11 years preceding the World Assembly in May
2015. Therefore, the Czech Republic had met the provisions of Article 11.4.3.
point 3 b). All cattle which were reared with the BSE cases during their first
year of life, and which investigation showed consumed the same potentially
contaminated feed during that period, if alive in the country, were completely
destroyed.
e) Compliance with conditions for ‘negligible BSE risk’ status - Article
11.4.3.
Based on the information provided, the Group recommended that the Czech
Republic be regarded as having met the requirements for recognition as complying
with the BSE Chapter of the Terrestrial Code as ‘negligible BSE risk’.
f) Conclusions
Recommended status: ‘Negligible BSE risk’.
3.3. France
In accordance with the established procedures, the participating expert
from France withdrew from the discussions on France’s dossier by the
Group.
The Group recalled that in July 2007 the OIE received a dossier from France
to evaluate the BSE risk status of its cattle population in accordance with the
Terrestrial Code. The recommendation of the Group at that time was that France
should be regarded as having met the requirements for recognition as complying
with the BSE Chapter of the Terrestrial Code as ‘controlled BSE risk’.
In September 2014, France submitted a dossier seeking a negligible BSE risk
status. The Group agreed that the submission conformed to the guidelines
circulated for Member Countries wishing to make a formal evaluation of their BSE
risk status according to the requirements of the Terrestrial Code.
The Group requested additional information and received clarification from
France. Points specifically noted by the Group were summarised in the following
discussion.
a) Section 1: Risk Assessment — Article 11.4.2. point 1
Risk assessment for entry of the BSE agent
The Group considered that the conclusion of the entry assessment was that
the risk that the BSE agent could have entered France during the interval
covered by the assessment, although very low, was not negligible.
Risk of recycling and amplification of the BSE agent
The Group considered that the conclusion of the exposure assessment was
that there was a negligible risk of recycling and amplification of the BSE agent
if it were present in France’s cattle population during the interval covered by
the assessment.
AHG BSE Risk Status Evaluation of Member Countries/November 2014 Annex 12
(contd)
Scientific Commission/February 2015 111
b) Surveillance according to Articles 11.4.20.-11.4.22.
The Group noted that the surveillance undertaken exceeded the minimum
requirements of type B surveillance according to Article 11.4.22. on
surveillance for BSE in the Terrestrial Code. 2,236,881 surveillance points were
collected, compared to a minimal requirement of 150,000 for an adult cattle
population of 10,269,158 over two years of age.
c) Other requirements — Article 11.4.2. points 2–4
Awareness programme
The Group determined that the awareness programme began in the early 1990’s
and met the requirements of the Terrestrial Code.
Compulsory notification and investigation
The Group noted that BSE was declared a notifiable disease under relevant
legislation since 1990 and determined that the system for compulsory
notification and investigation met the requirements of the Terrestrial
Code.
Laboratory examination
The Group determined that the arrangements for laboratory examination met
the requirements of the Terrestrial Manual.
Appropriate level of control and audit of the feed ban
The Group noted that the appropriate legislation, control and audit of the
proper implementation of the feed ban had been in force for at least eight
years.
d) BSE history in the country
The Group noted that France had reported 985 cases of BSE. The youngest BSE
case was born in April 2004, meaning that all indigenous cases would have been
born more than 11 years preceding the World Assembly in May 2015. Therefore,
France had met the provisions of Article 11.4.3. point 3 b). All cattle which
were reared with the BSE cases during their first year of life, and which
investigation showed consumed the same potentially contaminated feed during that
period, if alive in the country, were completely destroyed.
e) Compliance with conditions for ‘negligible BSE risk’ status - Article
11.4.3.
Based on the information provided, the Group recommended that France be
regarded as having met the requirements for recognition as complying with the
BSE Chapter of the Terrestrial Code as ‘negligible BSE risk’.
f) Conclusions
Recommended status: ‘Negligible BSE risk’.
3.4. Ireland
The Group recalled that in July 2007 the OIE received a dossier from
Ireland to evaluate the BSE risk status of its cattle population in accordance
with the Terrestrial Code. The recommendation of the Group at that time was that
Ireland should be regarded as having met the requirements for recognition as
complying with the BSE Chapter of the Terrestrial Code as ‘controlled BSE
risk’.
In September 2014, Ireland submitted a dossier seeking a negligible BSE
risk status. The Group agreed that the submission conformed to the guidelines
circulated for Member Countries wishing to make a formal evaluation of their BSE
risk status according to the requirements of the Terrestrial Code.
The Group requested additional information and received clarification from
Ireland. Points specifically noted by the Group were summarised in the following
discussion.
Annex 12 (contd) AHG BSE Risk Status Evaluation of Member
Countries/November 2014
112 Scientific Commission/February 2015
a) Section 1: Risk Assessment — Article 11.4.2. point 1
Risk assessment for entry of the BSE agent
The Group considered that the conclusion of the entry assessment was that
the risk that the BSE agent could have entered Ireland during the interval
covered by the assessment, although very low, was not negligible.
Risk of recycling and amplification of the BSE agent
The Group considered that the conclusion of the exposure assessment was
that there was a negligible risk of recycling and amplification of the BSE agent
if it were present in Ireland’s cattle population during the interval covered by
the
assessment.
b) Surveillance according to Articles 11.4.20.-11.4.22.
The Group noted that the surveillance undertaken exceeded the minimum
requirements of type B surveillance according to Article 11.4.22. on
surveillance for BSE in the Terrestrial Code. 584,475 surveillance points were
collected, compared to a minimal requirement of 150,000 for an adult cattle
population of 3,123,200 over two years of age.
c) Other requirements — Article 11.4.2. points 2–4
Awareness programme
The Group determined that the awareness programme began in 1996 and met the
requirements of the Terrestrial Code.
Compulsory notification and investigation
The Group noted that BSE was declared a notifiable disease under relevant
legislation since 1989 and determined that the system for compulsory
notification and investigation met the requirements of the Terrestrial
Code.
Laboratory examination
The Group determined that the arrangements for laboratory examination met
the requirements of the Terrestrial Manual.
Appropriate level of control and audit of the feed ban
The Group noted that the appropriate legislation, control and audit of the
proper implementation of the feed ban had been in force for at least eight
years.
d) BSE history in the country
The Group noted that Ireland had reported 1659 cases of BSE. The youngest
BSE case was born in April 2004, meaning that all indigenous cases would have
been born more than 11 years preceding the World Assembly in May 2015.
Therefore, Ireland had met the provisions of Article 11.4.3. point 3 b).
All cattle which were reared with the BSE cases during their first year of life,
and which investigation showed consumed the same potentially contaminated feed
during that period, if alive in the country, were completely destroyed.
e) Compliance with conditions for ‘negligible BSE risk’ status - Article
11.4.3.
Based on the information provided, the Group recommended that Ireland be
regarded as having met the requirements for recognition as complying with the
BSE Chapter of the Terrestrial Code as ‘negligible BSE risk’.
f) Conclusions
Recommended status: ‘Negligible BSE risk’.
3.5. Liechtenstein
In accordance with the established procedures, the participating expert
from Switzerland, expressing a possible conflict of interest, withdrew from the
discussions on Liechtenstein’s dossier by the Group.
AHG BSE Risk Status Evaluation of Member Countries/November 2014 Annex 12
(contd)
Scientific Commission/February 2015 113
The Group recalled that in January 2008 the OIE received a dossier from
Liechtenstein to evaluate the BSE risk status of its cattle population in
accordance with the Terrestrial Code. The recommendation of the Group at that
time was that Liechtenstein should be regarded as having met the requirements
for recognition as complying with the BSE Chapter of the Terrestrial Code as
‘controlled BSE risk’.
In September 2014, Liechtenstein submitted a dossier seeking a negligible
BSE risk status. The Group agreed that the submission conformed to the
guidelines circulated for Member Countries wishing to make a formal evaluation
of their BSE risk status according to the requirements of the Terrestrial
Code.
Points specifically noted by the Group were summarised in the following
discussion.
a) Section 1: Risk Assessment — Article 11.4.2. point 1
Risk assessment for entry of the BSE agent
The Group considered that the conclusion of the entry assessment was that
the risk that the BSE agent could have entered Liechtenstein during the interval
covered by the assessment, although very low, was not negligible.
Risk of recycling and amplification of the BSE agent
The Group considered that the conclusion of the exposure assessment was
that there was a negligible risk of recycling and amplification of the BSE agent
if it were present in Liechtenstein’s cattle population during the interval
covered by the assessment.
b) Surveillance according to Articles 11.4.20.-11.4.22.
The Group noted that the surveillance undertaken met the minimum
requirements of type B surveillance according to Article 11.4.22. on
surveillance for BSE in the Terrestrial Code. 399 surveillance points were
collected, compared to a minimal requirement of 300 for an adult cattle
population of 3.500 over two years of age. The Group also acknowledged the close
interrelationship between Liechtenstein’s and Switzerland’s Veterinary
Services.
c) Other requirements — Article 11.4.2. points 2–4
Awareness programme
The Group determined that the awareness programme began in 1989 and met the
requirements of the Terrestrial Code.
Compulsory notification and investigation
The Group noted that BSE was declared a notifiable disease under relevant
legislation since 1990 and determined that the system for compulsory
notification and investigation met the requirements of the Terrestrial
Code.
Laboratory examination
The Group determined that the arrangements for laboratory examination met
the requirements of the Terrestrial Manual.
Appropriate level of control and audit of the feed ban
The Group noted that the appropriate legislation, control and audit of the
proper implementation of the feed ban had been in force for at least eight
years.
d) BSE history in the country
The Group noted that Liechtenstein had reported two cases of BSE. The
youngest birth cohort reported as affected by BSE was born in 1993, meaning that
all indigenous cases were born more than 11 years preceding the submission of
the dossier. Therefore, Liechtenstein had met the provisions of Article 11.4.3.
point 3 b). All cattle which were reared with the indigenous BSE cases during
their first year of life, and which investigation showed consumed the same
potentially contaminated feed during that period, if alive in the country, were
completely destroyed.
Annex 12 (contd) AHG BSE Risk Status Evaluation of Member
Countries/November 2014
114 Scientific Commission/February 2015
e) Compliance with conditions for ‘negligible BSE risk’ status - Article
11.4.3.
Based on the information provided, the Group recommended that Liechtenstein
be regarded as having met the requirements for recognition as complying with the
BSE Chapter of the Terrestrial Code as ‘negligible BSE risk’.
f) Conclusions
Recommended status: ‘Negligible BSE risk’.
3.6. Switzerland
In accordance with the established procedures, the participating expert
from Switzerland withdrew from the discussions on Switzerland’s dossier by the
Group.
The Group recalled that in January 2007 the OIE received a dossier from
Switzerland to evaluate the BSE risk status of its cattle population in
accordance with the Terrestrial Code. The recommendation of the Group at that
time was that Switzerland should be regarded as having met the requirements for
recognition as complying with the BSE Chapter of the Terrestrial Code as
‘controlled BSE risk’.
In September 2014, Switzerland submitted a dossier seeking a negligible BSE
risk status. The Group agreed that the submission conformed to the guidelines
circulated for Member Countries wishing to make a formal evaluation of their BSE
risk status according to the requirements of the Terrestrial Code.
Points specifically noted by the Group were summarised in the following
discussion.
a) Section 1: Risk Assessment — Article 11.4.2. point 1
Risk assessment for entry of the BSE agent
The Group considered that the conclusion of the entry assessment was that
the risk that the BSE agent could have entered Switzerland during the interval
covered by the assessment, although very low, was not negligible.
Risk of recycling and amplification of the BSE agent
The Group considered that the conclusion of the exposure assessment was
that there was a negligible risk of recycling and amplification of the BSE agent
if it were present in Switzerland’s cattle population during the interval
covered by the assessment.
b) Surveillance according to Articles 11.4.20.-11.4.22.
The Group noted that the surveillance undertaken exceeded the minimum
requirements of type B surveillance according to Article 11.4.22. on
surveillance for BSE in the Terrestrial Code. 104,961 surveillance points were
collected, compared to a minimal requirement of 95,350 for an adult cattle
population of 830,000 over two years of age.
c) Other requirements — Article 11.4.2. points 2–4
Awareness programme The Group determined that the awareness programme
began in 1989 and met the requirements of the Terrestrial Code.
Compulsory notification and investigation
The Group noted that BSE was declared a notifiable disease under relevant
legislation since 1990 and determined that the system for compulsory
notification and investigation met the requirements of the Terrestrial
Code.
Laboratory examination
The Group determined that the arrangements for laboratory examination met
the requirements of the Terrestrial Manual.
AHG BSE Risk Status Evaluation of Member Countries/November 2014 Annex 12
(contd)
Scientific Commission/February 2015 115
Appropriate level of control and audit of the feed ban
The Group noted that the appropriate legislation, control and audit of the
proper implementation of the feed ban had been in force for at least eight
years.
d) BSE history in the country
The Group noted that Switzerland had reported 467 cases of BSE. The
youngest birth cohort reported as affected by BSE was born in 2003, meaning that
all indigenous cases were born more than 11 years preceding the submission of
the dossier. The Group acknowledged that the last BSE-case diagnosed as atypical
BSE in Switzerland in 2012 and born in 2005, was imported from Germany at the
age of 17 months. Therefore, Switzerland had met the provisions of Article
11.4.3. point 3 b). All cattle which were reared with the indigenous BSE cases
during their first year of life, and which investigation showed consumed the
same potentially contaminated feed during that period, if alive in the country,
were completely destroyed.
e) Compliance with conditions for ‘negligible BSE risk’ status - Article
11.4.3.
Based on the information provided, the Group recommended that Switzerland
be regarded as having met the requirements for recognition as complying with the
BSE Chapter of the Terrestrial Code as ‘negligible BSE risk’.
f) Conclusions
Recommended status: ‘Negligible BSE risk’.
3.7. Other Member Country requests
The Group assessed two additional requests from Member Countries for the
recognition of their BSE risk status. One did not meet the requirements of the
Terrestrial Code and the dossier was referred back to the corresponding Member
Country. For the second, the Group recommended that a mission be conducted to
the corresponding Member Country to verify compliance with Chapter 11.4. of the
Terrestrial Code.
4. Revision of Chapter 11.4. of the Terrestrial Animal Health Code on BSE
to consider atypical BSE
The Group summarised current scientific knowledge on several key questions
to examine whether and how atypical BSE should be considered in Chapter 11.4. of
the Terrestrial Code on BSE. The Group referred to its discussion of atypical
BSE two years before, available in the report of its November 2012 meeting and
invited the Scientific Commission and Member Countries to reflect on its
content.
As the outcome of its discussion, the Group agreed that atypical BSE should
be differentiated from classical BSE in Chapter 11.4. of the Terrestrial Code on
BSE including its impact on BSE risk status recognition, maintenance and
associated surveillance.
With regard to Article 11.4.25. the Group agreed that import of ruminants
other than cattle is not considered to be a risk and therefore proposed to
replace ruminant by cattle or bovine in the entire chapter, except in reference
to the ruminant-to-ruminant feed ban. The suggested change is consistent with
the chapter’s evolution of focus from ruminants to cattle in preceding
iterations.
The chapter was modified as follows:
Article 11.4.1.: General provisions and safe commodities
The Group clarified that the recommendations of the chapter cover both
atypical and classical BSE.
Annex 12 (contd) AHG BSE Risk Status Evaluation of Member
Countries/November 2014
116 Scientific Commission/February 2015
Article 11.4.2.: The BSE risk status of the cattle population of a country,
zone or compartment
The Group agreed that atypical BSE has to be considered to occur at the
same rare background prevalence in any given cattle population. Therefore, the
Group specified that the risk assessment should consider the potential factors
for classical BSE occurrence.
Entry assessment: the presence or absence of classical BSE agent should be
carefully considered. The Group therefore proposed to slightly change Point 1 a
i).
Exposure assessment: considering the probable rare background prevalence of
atypical BSE in every indigenous bovine population, the Group emphasised that
the exposure assessment be performed in every case, irrespective of the entry
assessment.
Surveillance: in light of the implications for surveillance forthcoming
from the declining tail of the classical BSE epidemic and the resulting, growing
relative importance of atypical BSE, the Group acknowledged that the
surveillance system should be revised in depth, including the potential
reinstatement of a single surveillance goal per mature cattle population
size.
The Group acknowledged that the current version of the Terrestrial Manual
did not provide information on the suitable tests to be used to discriminate
atypical from classical BSE. The Group recommended that Member Countries
substantiate their findings with the support of the OIE Reference Laboratories
for BSE.
Therefore the Group suggested the Scientific Commission to discuss with the
Biological Standard Commission whether a revision of the BSE chapter of the
Terrestrial Manual would be needed to consider tests able to discriminate
atypical from classical BSE.
Article 11.4.3.: Negligible BSE risk
The Group agreed that the occurrence of atypical BSE cases (irrespective of
age or birth year) should not influence official risk status, as long as the
criteria of Article 11.4.2. have been complied with and an appropriate level of
control gives evidence that the ruminant-to-ruminant feed ban has been efficient
for the last eight years. The Group clarified that the follow-up of the cohorts
of BSE cases was not applicable to atypical BSE cases since atypical BSE is not
linked to feed practices.
Article 11.4.4.: Controlled BSE risk
The Group proposed changes similar to those proposed in Article
11.4.3.
Article 11.4.7.: Recommendations for the importation of cattle from a
country, zone or compartment posing a negligible BSE risk but where there has
been an indigenous case In accordance with the above changes, the Group
clarified that these recommendations would be valid for a country, zone or
compartment having a negligible BSE risk but only where there has been an
indigenous case of classical BSE.
Article 11.4.9.: Recommendations for the importation of cattle from a
country, zone or compartment posing an undetermined BSE risk
The Group proposed changes in line with those proposed in Article
11.4.3.
Article 11.4.10.: Recommendations for the importation of meat and meat
products from a country, zone or compartment posing a negligible BSE risk
The Group clarified that the requirement in point 3 applies to countries
with negligible BSE risk and one or more indigenous cases of classical
BSE.
AHG BSE Risk Status Evaluation of Member Countries/November 2014 Annex 12
(contd)
Scientific Commission/February 2015 117
The Group also considered the risk posed by atypical BSE and proposed a
recommendation ensuring that the products were not contaminated with tissues
listed in the newly proposed point 4 of Article 11.4.14. (brain, eye, spinal
cord and skull from cattle aged more than 96 months).
Article 11.4.13.: Recommendations on ruminant-derived meat-and-bone meal or
greaves
The Group discussed the risk of trading of ruminant MBM, acknowledging that
atypical BSE was likely to exist in every domestic cattle population.
Considering that the feed ban is the most important mitigating measure to avoid
recycling, the Group proposed for countries with recognised negligible risk
status for BSE, with or without reported cases, consideration that trade of
ruminant MBM be restricted to cattle born after the effective enforcement of the
ruminant-to-ruminant feed ban.
Article 11.4.14.: Recommendations on commodities that should not be
traded
Considering that atypical BSE was likely to exist in any bovine population
and the age distribution of atypical BSE cases, the Group recommended that
brain, eye, spinal cord and skull not be traded if originated from cattle over
96 months (eight years) from negligible BSE risk countries and added a paragraph
to this article.
Article 11.4.16.: Recommendations for the importation of tallow (other than
as defined in Article 11.4.1.) intended for food, feed, fertilisers, cosmetics,
pharmaceuticals including biologicals, or medical devices and Article 11.4.18.:
Recommendations for the importation of tallow derivatives (other than those
made from tallow as defined in Article 11.4.1.) intended for food, feed,
fertilisers, cosmetics, pharmaceuticals including biologicals, or medical
devices
The changes in these two articles were proposed to reflect the proposal of
Article 11.4.14.
Article 11.4.20.: Surveillance: introduction
The Group considered that the article was valid for both classical and
atypical BSE.
Article 11.4.21.: Surveillance: description of cattle subpopulations
The Group estimated that the differentiation of classical and atypical BSE
should be mentioned in the definition of the cattle sub-population.
Point 1: cattle over 30 months of age displaying behavioural or clinical
signs consistent with BSE (clinical suspects).
The Group agreed that this should be limited to classical BSE as atypical
cases do not show classical signs of BSE.
Article 11.4.22.: Surveillance activities
The Group agreed that the statistical model should be revised in depth to
consider the evolution of classical BSE epidemiology, as well as the
specificities of atypical surveillance.
The Group highlighted the following points to be taken into account in the
potential revision of the statistical BSE model:
- Recalculation of the relative risk of positive BSE test by age and
population stream
- Retention of current target populations
- Appropriateness of current target prevalence and merits of one type of
surveillance ;
- Confidence level retention at 95%;
Annex 12 (contd) AHG BSE Risk Status Evaluation of Member
Countries/November 2014
118 Scientific Commission/February 2015
- Design prevalence of at least one case per 100,000 in the adult
population (current type A surveillance);
- Re-weighting of focus in favour of older animals
- Retention of sampling in younger animals;
- European Commission and OIE databases of all tested animals, including
positives and their ages.
The Group agreed to revise the model for BSE surveillance in the weeks
following the meeting and proposed a new model based on an estimation of the BSE
incidence. Unfortunately the BSE surveillance point values of the proposed model
were not applicable to all OIE Member Countries already having a BSE risk
status.
The Group acknowledged that the seven years of surveillance was referring
to the 95th percentile of the incubation period of classical BSE. However,
considering the need of continuous surveillance, the Group agreed to maintain
the possibility to accumulate points over the years. The proposal of seven years
was kept with relation to classical BSE. However, the Group agreed that this may
need to be revised once the incubation period of atypical BSE is known.
Article 11.4.23: BSE risk assessment: introduction
Changes were proposed to reflect the proposal of Article 11.4.2. and to
clarify the wording.
Article 11.4.24.: The potential for the entry of the BSE agent through the
importation of meat-and-bone meal or greaves The Group adjusted the text in line
with the proposed changes of previous articles.
Article 11.4.25.: The potential for the entry of the BSE agent through the
importation of live animals potentially infected with BSE
The Group updated the article by clarifying that import of ruminants other
than cattle is not considered to be a risk, and that import of cattle could
present a risk of entry of the classical BSE agent when coming from countries
with classical BSE.
The Group deleted the reference to hypothetical maternal transmission as
its epidemiological significance has been downplayed.
Article 11.4.26.: The potential for the entry of the BSE agent through the
importation of products of animal origin potentially infected with BSE
In addition to the changes already proposed in previous article, the Group
proposed to delete the reference to feeding practices in dairy cows due to the
imposed feed ban.
The Group also removed the reference to the length of time the animals
lived in a country as this article is related to import of products and not of
live animals. However, the Group clarified that these products should not
encompass tissues known to contain BSE infectivity.
Article 11.4.27.: The potential for the exposure of cattle to the BSE agent
through consumption of meat-and-bone meal or greaves of ruminant origin
Safe commodities being specifically listed in Article 11.4.1., the Group
considered it inadequate to keep reference only to milk and blood in this
article.
Article 11.4.28.: The origin of animal waste, the parameters of the
rendering processes and the methods of animal feed production
The Group agreed to delete the first four bullet points that were not
relevant for the purpose of this article.
AHG BSE Risk Status Evaluation of Member Countries/November 2014 Annex 12
(contd)
Scientific Commission/February 2015 119
The Group considered that reticulo-endothelial tissues could not be
included in the list of tissues where BSE agent is present at much higher titres
and removed it to consider as specified risk material (SRM) only the central
nervous system.
Article 11.4.29.: Conclusions of the risk assessment
The Group clarified the risk linked to classical BSE and to atypical
BSE.
5. Consideration of the information provided by authors of the BSurvE model
with regards to its update
The Group acknowledged that the authors of the BSurvE model could not
update the model despite the need to consider the global evolution of BSE.
6. General considerations and advice to be provided to future applicant
Member Countries
On a structural aspect, the Group strongly recommended that applicant
Member Countries adhere to the questionnaire of Article 1.6.5. of the
Terrestrial Code, answering all questions clearly and concisely. While
acknowledging the importance of some appendices, the Group recalled that the
central points should be covered in the core document. Appendices should be
clearly cross-referenced in the dossier and their titles should provide the key
words of their contents.
The Group would appreciate the presentation of a short summary/conclusion
at the end of each section.
The Group clarified that full regulatory texts are not needed in the
dossier but that a summary of the important regulatory texts should be provided
to help the experts to understand the national situation.
The Group would expect that Member Countries, conducting visual inspection
in feed mills and renderers, would identify apparent infractions, and would
include explanations on the follow-up procedure applied to rule
cross-contamination out.
The Group noted that the measures to mitigate the exposure assessment (feed
ban, SRM removal, cross-contamination controls) were often not sufficiently
detailed in the dossiers.
The Group was requested to provide advice on relevant points that should be
covered in the workshop on the OIE procedure for the official recognition of
country status, with reference to BSE. The Group identified the following as
points of the questionnaire that would need explanations from the
trainers:
- The definition and difference between feed mills and rendering
plants
- The tables of the questionnaire related to the feed ban
- The surveillance point system
- The collection of the data and diagnostic protocols
The Group suggested that the trainers put the participants in the role of
reviewers. A possibility could be to present blind extracts from several
dossiers and request their opinions.
The Group also mentioned the potential merit in revisiting the entire cycle
of BSE infectivity concurrently identifying where the risks are and where
associated inspections are needed.
7. Other matters
The Group recommended that the Scientific Commission schedules the revision
of the questionnaire (Article 1.6.5. of the Terrestrial Code). The Group
suggested that such revision considers:
- Weighting of the exposure assessment with relation to the global
evolution of BSE epidemiology;
Annex 12 (contd) AHG BSE Risk Status Evaluation of Member
Countries/November 2014
120 Scientific Commission/February 2015
- Definition of technical words such as rendering plants, feed mills,
cohort;
- Inclusion of questions related to the capability of the Veterinary
Services and disease notification.
Considering the difficulties faced in the evaluation of some dossiers as a
result of translation issues, the Group suggested that some technical terms
(such as those of the Glossary) be translated into more languages than the OIE
official languages such as Russian, Arabic, Chinese, Portuguese and
Japanese.
8. Finalisation and adoption of the draft report
The Group reviewed and amended the draft report provided by the rapporteur.
The Group agreed that the report reflected the discussions.
_______________
…/Appendices
AHG BSE Risk Status Evaluation of Member Countries/November 2014 Annex 12
(contd)
Scientific Commission/February 2015 121
Appendix I
MEETING OF THE OIE AD HOC GROUP ON BOVINE SPONGIFORM ENCEPHALOPATHY (BSE)
RISK STATUS EVALUATION OF MEMBER COUNTRIES
Paris, 25-27 November 2014
_______
Agenda
1. Opening
2. Adoption of the agenda and appointment of chairperson and
rapporteur
3. Evaluation of applications from Member Countries for official
recognition of BSE risk status
- Cyprus
- Ireland
- Czech Republic
- Liechtenstein
- France
- Switzerland
4. Revision of Chapter 11.4. of the Terrestrial Animal Health Code on BSE
to consider atypical BSE
5. Consideration of the information provided by authors of the BSurvE model
with regards to its update
6. General considerations and advices to be provided to future applicant
Member Countries
7. Other matters
8. Finalisation and adoption of the draft report
____________
Annex 12 (contd) AHG BSE Risk Status Evaluation of Member
Countries/November 2014
122 Scientific Commission/February 2015
Appendix II
MEETING OF THE OIE AD HOC GROUP ON BOVINE SPONGIFORM ENCEPHALOPATHY (BSE)
RISK STATUS EVALUATION OF MEMBER COUNTRIES
Paris, 25-27 November 2014
_____
List of participants
MEMBERS
Dr Armando Giovannini Istituto Zooprofilattico Sperimentale dell'Abruzzo e
del Molise "G. Caporale" Via Campo Boario, 64100 Teramo ITALY Tel: (39 0861) 33
24 27 Fax (39 0861) 33 22 51 a.giovannini@izs.it
Dr Concepción Gómez Tejedor Ortiz (Invited but could not attend) Directora,
Laboratorio Central de Veterinaria Ctra de /algete Km 8 28110 Algete, Madrid
SPAIN Tel: (34 913) 47 92 77 Fax: (34 916) 29 05 98 cgomezte@magrama.es
Dr Dagmar Heim Animal, Health, veterinary medicines and antibiotics Federal
Food Safety and Veterinary Office Schwarzenburgstrasse 155, PO box 3003 Bern
SWITZERLAND Tel: (41-58) 464 99 93 Fax: (41-31) 323 85 94
dagmar.heim@bvet.admin.ch
Dr John A. Kellar (Attended via teleconference) TSE Policy Coordinator
Animal Products Directorate Canadian Food Inspection Agency 3851 Fallowfield
Road Room C305 Ottawa K2H 8P9 CANADA Tel: (1.613) 228 66 90 (54 07) Fax: (1.613)
228 66 75 john.kellar@inspection.gc.ca
Dr Martial Plantady Legislative officer European Commission Health &
Consumers Unit G4: food, alert system and training B232 03/22 B-1049
Brussels/Belgium +32 2 298 66 70 martial.plantady@ec.europa.eu
Dr Rodolfo C. Rivero National Coordinator TSE Ministry of Livestock,
Agriculture & Fisheries Director Norwest Regional Laboratory Veterinary
Laboratorios Directorate “Miguel C. Rubino” C.C. 57037 C.P. 6000 Paysandù
URUGUAY Tel (598) 72 25229 or 27871 Fax (598) 72 27614 rrivero@mgap.gub.uy
Dr Shigeki Yamamoto Professor, Tokai University, School of Marine Science
and Technology, Department of Fisheries, Course of Food Sc1ence, 3-20-1, Orido,
Shimizu-ku, Shizuoka-city, Shizuoka, 424-8610, Japan Tel: 81 54 334 0411 Fax: 81
54 337 0239 syamamoto@tokai-u.jp
Representative SCAD Prof. Thomas C. Mettenleiter
Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health
Südufer 10 , 17493 Greifswald , Insel Riems GERMANY Tel.: (49-38) 351 71 02
thomas.mettenleiter@fli.bund.de
OIE HEADQUARTERS Dr Bernard Vallat Director General 12 rue de Prony 75017
Paris FRANCE Tel: 33 - (0)1 44 15 18 88 Fax: 33 - (0)1 42 67 09 87
oie@oie.int
Dr Elisabeth Erlacher-Vindel Deputy Head Scientific and Technical
Department e.erlacher-vindel@oie.int
Dr Simona Forcella Chargée de mission Scientific and Technical Department
s.forcella@oie.int
Dr Laure Weber-Vintzel Officer in charge of the recognition of disease
status Scientific and Technical Department
l.weber-vintzel@oie.int
______________
http://www.oie.int/fileadmin/Home/eng/Internationa_Standard_Setting/docs/pdf/SCAD/A_SCAD_Feb2015.pdf
Sunday, October 18, 2015
*** World Organisation for Animal Health (OIE) and the Institut Pasteur
Cooperating on animal disease and zoonosis research ***
Saturday, September 19, 2015
Wednesday, September 23, 2015
NIH Availability for Licensing AGENCY: [FR Doc. 2015–24117 Filed 9–22–15;
8:45 am] Detection and Discrimination of Classical and Atypical L-Type BSE
Strains by RT-QuIC
Friday, December 5, 2014
*** SPECIAL ALERT The OIE recommends strengthening animal disease
surveillance worldwide OIE
BSE TSE PRION AKA MAD COW DISEASE ? ‘’the silence was deafening’’ ...tss
http://transmissiblespongiformencephalopathy.blogspot.com/2014/12/special-alert-oie-recommends.html
Monday, May 05, 2014
Member Country details for listing OIE CWD 2013 against the criteria of
Article 1.2.2., the Code Commission recommends consideration for listing
Thursday, December 20, 2012
OIE GROUP RECOMMENDS THAT SCRAPE PRION DISEASE BE DELISTED AND SAME OLD BSe
WITH BOVINE MAD COW DISEASE
Wednesday, February 16, 2011
IN CONFIDENCE
SCRAPIE TRANSMISSION TO CHIMPANZEES
IN CONFIDENCE
Tuesday, July 14, 2009 U.S.
*** Emergency Bovine Spongiform Encephalopathy Response Plan Summary and
BSE Red Book
Date: February 14, 2000 at 8:56 am PST
WHERE did we go wrong $$$
http://madcowtesting.blogspot.com/2009/07/us-emergency-bovine-spongiform.html
Monday, November 30, 2009
*** USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL
HEALTH CODE, DOES NOT SURPRISE ME $
Tuesday, January 1, 2008
BSE OIE USDA
Subject: OIE BSE RECOMMENDATION FOR USA, bought and paid for by your local
cattle dealers i.e. USDA
Date: May 14, 2007 at 9:00 am PST
OIE BSE RECOMMENDATION FOR USA, bought and paid for by your local cattle
dealers i.e. USDA
STATEMENT BY DR. RON DEHAVEN REGARDING OIE RISK RECOMMENDATION
March 9, 2007
Thursday, October 22, 2015
Former Ag Secretary Ann Veneman talks women in agriculture and we talk mad
cow disease USDA and what really happened
Tuesday, July 14, 2009 U.S.
*** Emergency Bovine Spongiform Encephalopathy Response Plan Summary and
BSE Red Book
Date: February 14, 2000 at 8:56 am PST
WHERE did we go wrong $$$
*** Qualitative Analysis of BSE Risk Factors in the United States
February 13, 2000 at 3:37 pm PST (BSE red book)
Comments on technical aspects of the risk assessment were then submitted to
FSIS.
Comments were received from Food and Water Watch, Food Animal Concerns
Trust (FACT), Farm Sanctuary, R-CALF USA, Linda A Detwiler, and Terry S.
Singeltary.
This document provides itemized replies to the public comments received on
the 2005 updated Harvard BSE risk assessment. Please bear the following points
in mind:
Owens, Julie
From: Terry S. Singeltary Sr. [flounder9@verizon.net]
Sent: Monday, July 24, 2006 1:09 PM
To: FSIS RegulationsComments
Subject: [Docket No. FSIS-2006-0011] FSIS Harvard Risk Assessment of Bovine
Spongiform Encephalopathy (BSE)
Page 1 of 98
FSIS, USDA, REPLY TO SINGELTARY
IN A NUT SHELL ;
(Adopted by the International Committee of the OIE on 23 May 2006)
11. Information published by the OIE is derived from appropriate
declarations made by the official Veterinary Services of Member Countries. The
OIE is not responsible for inaccurate publication of country disease status
based on inaccurate information or changes in epidemiological status or other
significant events that were not promptly reported to the Central Bureau,
Terry S. Singeltary Sr. Bacliff, Texas USA 77518 flounder9@verizon.net
Your comment was submitted successfully!
Comment Tracking Number: xxxxxxxxxxxxxx
Your comment may be viewable on Regulations.gov once the agency has reviewed it. This process is dependent on agency public submission policies/procedures and processing times. Use your tracking number to find out the status of your comment.
Agency: Animal and Plant Health Inspection Service (APHIS)
Document Type: Rulemaking
Title: Scrapie in Sheep and Goats
Document ID: APHIS-2007-0127-0001
Your comment was submitted successfully!
Comment Tracking Number: xxxxxxxxxxxxxx
Your comment may be viewable on Regulations.gov once the agency has reviewed it. This process is dependent on agency public submission policies/procedures and processing times. Use your tracking number to find out the status of your comment.
Agency: Animal and Plant Health Inspection Service (APHIS)
Document Type: Rulemaking
Title: Scrapie in Sheep and Goats
Document ID: APHIS-2007-0127-0001
posted by Terry S. Singeltary Sr. | 10:58 AM
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