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From: TSS ()
Subject: SCRAPIE: ERADICATE IT Nor98-Like Scrapie Found in the United States
Date: April 12, 2008 at 7:29 pm PST


The sheep industry's scrapie eradication efforts. American Sheep

Industry Association

The goal of the American Sheep Industry Association (ASI) and the U.S. sheep
industry is to eradicate
scrapie from our borders by 2010. In addition, it is the objective to have
the World Organization for Animal
Health, OIE, declare the United States scrapie free by 2017. This quarterly
publication is created specifically
for those of you in the field who are also working to achieve this goal.

This newsletter brings together, into one spot, current information from all
50 states, as well as from
the U.S. Department of Agriculture and any other organization providing
scrapie news, and reports it back
to the field.

If you have first-hand accounts that you believe would be relevant for
others to read or have
information that you would like included in this newsletter, please let us
know at

March 2008

Nor98-Like Scrapie Found in the United States


Sheep Industry News Associate Editor

In February of last year, the U.S. Department of Agriculture?s (USDA) Animal
and Plant Health Inspection
Service (APHIS) officially announced the discovery of a Nor98-like scrapie
case in a ewe from a flock in
Wyoming. This was the first case of scrapie consistent with Nor98 discovered
in the United States.
Since then, four more cases have been discovered that originated from flocks
in Colorado, Indiana,
Minnesota and California. These cases are not related to either the first
one in Wyoming or to each other.
This scrapie type was first found in Norway in 1998 and has since been found
in sheep and goats in
many countries in Europe.

?It does affect goats,? says Diane Sutton, DVM, national scrapie coordinator
for USDA. ?So far not here
in the United States, but chances are, we might eventually see it in goats
here too.?
This type of scrapie affects sheep of all commonly occurring genotypes
including those that are resistant
to classical scrapie.

According to Sutton, those flocks in the United States that are found to be
infected with Nor98-like scrapie
will not be able to use the current genetic-base approach to flock clean up.
Producers whose flocks have risk
factors for classical scrapie are still encouraged to test at codon 171 for
classical scrapie resistance, as has
been done in the past.

The World Organization for Animal Health (OIE) has formed an ad hoc
committee to consider how to
address Nor98-like scrapie with respect to trade. It will likely be at least
two years before a code change
could be made should a consensus be reached.

?Until research provides us with other options for eliminating Nor98-like
scrapie and the international
community reaches a consensus on guidelines for trade we will continue to
use flock depopulation and exposure-
based clean up plans for Nor98-like scrapie affected flocks,? says Sutton.
?As other viable options are
identified, we will evaluate them using pilot projects.?

According to Linda Detwiler, DVM, assistant director, Center for Public and
Corporate Veterinary
Medicine, it is important to note that it isn?t known if the appearance of
non-classical scrapie cases in Europe
and the United States are more likely due to the increased ability to test
for and detect non-classical
scrapie than to increasing rates of infection. Scientists in European
countries are beginning to look at
archived samples in an attempt to identify non-classical cases that may have
occurred earlier than 1998.
?I would caution everyone that it?s premature to be able to say much of
anything about these non- classical
cases. At this point in time, there are many unknowns such as: 1) is there
more than one strain, 2)
what is the origin, 3) are there natural modes of transmission, 4) does the
genotype affect incubation time
and clinical presentation, 5) do codons other than 136, 141, 154 and 171
influence these cases and 6) how
long have these cases been occurring?? she questions.

Because of Europe?s increased awareness of non-classical scrapie, there has
been quite a bit of research
into understanding how and if the disease is transmitted and how it affects
Research is currently underway in the United States.

?The first U.S. material became available in February, so ARS (Agricultural
Research Service) is gearing
up to study it. But, because of the nature and long-term aspects of the
disease, it will take a while to study,
so we will probably be seeing research from Europe published first,? Sutton

In the meantime, it is stressed that officials will continue to handle the
disease as it has in the past,
and that producers should be aware of Nor98-like scrapie but not alarmed.

?We are going to treat it as scrapie until the international community
removes it as a trade barrier or
science finds that there is a better way to handle it than the current
system,? Sutton says.

Jim Logan?s, DVM, chair of ASI?s Animal Health Committee, best advice to
producers to protect their flock
from Nor98-like scrapie is to maintain a closed ewe flock. He says that to
prevent the introduction of all scrapie
types, producers need to be aware of where new purchases are coming from,
know the genetics of new
purchases and avoid purchasing ewes unless familiar with the scrapie status
of the farm of origin or
maintain a closed ewe flock.

?Essentially, people need to use common sense and maintain good sanitation
and husbandry practices,?
he explains.

Nor98 is a relatively common prion disease or transmissible spongiform
encephalopathy of sheep. The
first descriptions of the disorder were in sheep diagnosed in 1998 in
Norway, although a retrospective study
has revealed a case in England in 1989. Improved methods for diagnostic
testing were published in 2002
and surveillance was initiated in many European countries. Most cases are
identified in clinically normal
sheep tested in routine slaughter surveillance. The disease is
experimentally transmissible to sheep and
genetically altered mice by inoculation into their brains but no data are
yet available on whether the
disease is transmitted between sheep in an affected flock.

Clinical Signs

Most cases have been discovered in clinically normal sheep tested at
slaughter. Of the few clinical cases,
a common sign is progressive incoordination (ataxia), occurring most likely
because the abnormal prions
accumulate in the cerebellum, the region of the brain (the cerebellum) that
integrates information coming
in from the senses with nerve impulses going to the muscles.


Both classical scrapie and Nor98-like scrapie are characterized by
accumulation of abnormal prion
proteins. However, the distribution of the prion proteins differ. In
classical scrapie, prions are usually
found earliest in the lymph nodes and later in the region of the brain
associated with innervation of the
gut. As discussed above, abnormal prions are found in different areas of the
brain in cases of Nor98. Further,
prion proteins are not found in the lymph nodes of sheep with Nor98 and the
current live animal tests of
lymphoid tissues are not suitable. Nor98 is a challenging diagnosis but
skilled pathologists, working with a
panel of three different diagnostic tests, can accurately diagnose the
disease in the brain of affected sheep.


Susceptibility to classical scrapie is associated with naturally occurring
differences in the gene for the
prion protein, particularly differences at position 136 and 171. Each sheep
has two copies of this gene and
commercially available genotype tests show the differences at those
positions. Sheep with the genotypes
136VV 171QQ and 136AV 171QQ are very susceptible to classical scrapie
strains. Sheep with the 136AA
171QQ genotype are susceptible to the most common classical scrapie strain
in the United States and
represent the most common genotype found in U.S. scrapie cases. Sheep with
at least one copy of the
gene 136A 171R are generally resistant to the more common type of classical
Although no genotype is considered to be resistant to Nor98-like scrapie,
the disorder is found most
frequently in sheep with changes in positions 141 and/or 154. The genetic
signature AFRQ indicates a
sheep with 136A and 171Q with the additional change to ?F? at 141. The
signature AHQ indicates a sheep
with 136A and 171Q with a change to ?H? at position 154. A large survey of
4,000 sheep in Europe and
numerous reports on smaller study populations has demonstrated that sheep
with either the AFRQ or the
AHQ gene were eight to 15 times more likely to be diagnosed with Nor98-like
scrapie than were sheep with
the most common genotype ARQ. Sheep with both changes were more than 20
times more likely to be
diagnosed with Nor98-like scrapie. Sheep with the 171R form of the gene are
generally resistant to
classical scrapie but are susceptible to Nor98-like scrapie, particularly in
171QR sheep that have an AFRQ


Classical scrapie is usually found in more than one sheep in a flock, with
prevalence as high as 30
percent with some scrapie strains. In contrast, more than one sheep with
Nor98-like scrapie is usually found

The Science Behind Nor98 in Sheep

only in flocks of more than 500 sheep. In addition to genotype, age appears
to represent a significant risk
factor for Nor98-like scrapie. In the large European study, 80 percent of
the cases of classical scrapie were
found in sheep ages 3-5, a finding similar to that reported in the US. In
contrast, more than 60 percent of
the sheep with Nor98-like scrapie were older than five years and more than
25 percent were more than 10
years old. Nor98 is found in most countries performing large-scale
surveillance; the disorder occurs at a
rate of approximately one in 1,400 mature sheep at slaughter even if the
rate of classical scrapie is very

The low prevalence of Nor98 within flocks, the wide geographic distribution
of the disorder, the range in
age of onset or diagnosis, and the genetic factors increasing the risk of
Nor98 are strikingly different than
those found in classical scrapie. There may be additional genetic factors
influencing development of this
disorder, in addition to factors such as route of infection or age at which
sheep are infected. Alternatively,
Nor98 may be a sporadic disease of sheep, appearing primarily but not
exclusively in older sheep. Additional
findings from experimental studies and large scale surveillance using
improved diagnostic methods will be
useful in understanding this wide-spread prion disease of sheep.

Background Information

Luhken and others, 2007, Veterinary Research 38: 65-80.
Bruce and others, 2007, Veterinary Record 160: 665-666.
Benestad and others, 2003, Veterinary Record 153: 202-208.
Animals Sampled for Scrapie Testing

Sheep and Goats

19,667 animals have been sampled for scrapie testing: 16, 710 RSSS; 1,474
goats for the CSPS
study; 1,224 regulatory field cases; 227 regulatory third eyelid biopsies;
and 32 regulatory rectal
biopsies. Testing of lympoid tissue obtained by rectal bopsy was approved by
USDA as an official
live-animal test on Jan. 11, 2008.

As of February 29, 2008

Infected and Source Flocks New Statuses by Year

FY 1997 ? 2008*
*Through February 29, 2008
Scrapie Confirmed Cases in 2008
Scrapie Flock Certification Program
Participating Flocks
SFCP Flocks Enrolled and Certified in February 2008
Through February 29, 2008
Total Enrolled Flocks?2,043
Complete Monitored?1,599
Export Monitored?5
Elective Monitored?4
Slaughter Surveillance Samples Collected by Month,
FY 2004 to FY 2008*
The Animal and Plant Health Inspection Service's goal is to collect 4,000
slaughter surveillance samples
each month from around the United States.
Regulatory Scrapie Slaughter Surveillance
(RSSS) Statistics
through February 29, 2008
*National Veterinary Services Laboratories
Web Sites Dedicated to the Eradication of Scrapie
Animal and Plant Health Inspection Service
Maryland Small Ruminant Page
National Institute of Animal Agriculture
Scrapie QuickPlace
State and federal employees can access this password-protected site by
e-mailing to receive a password.
American Sheep Industry Association
Since April 1, 2003:
161,909 samples collected
352 NVSL* confirmed positive
In FY2008:
16,710 samples collected
10 NVSL confirmed positive
* Through February 29, 2008

Friday, April 11, 2008


It is highly likely that sheep were exposed to BSE during the BSE epidemic
in cattle. However, despite
extensive Transmissible Spongiform Encephalopathy (TSE) surveillance in
sheep there is no evidence that
BSE is present in the UK sheep flock now. *{The relatively recent
identification of atypical scrapie and
paucity of experimental data about its transmissibility either between sheep
or to humans have raised
concerns about the possible animal and public health implications of this

Tissue distribution. For atypical scrapie, what is PrPres and
infectivity distribution within sheep of different genotypes,
particularly with respect to SRM removal? For classical
scrapie and experimental BSE in sheep, tissue distribution of
infectivity is widespread. Thus, even with SRM controls in
place, an infected sheep poses around 1000 times the risk to
human health than does an infected cow22. Does the
distribution depend on whether infection is by the oral or
21 Gubbins S. Prevalence of BSE in sheep: interpreting the results of
retrospective and
prospective testing of sheep TSE cases. SEAC 84 open meeting
22 paper presented to Food Standards Agency board on 9 December 2004.
Also see paper SEAC/84/2 Annex 2: McLean, A.
Page 13
© SEAC 27 February 2006
intracerebral route? Are some VRQ sheep carriers with no
neurological symptoms?



Aspects of the Cerebellar Neuropathology in Nor98

Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1
1National Veterinary Insitute, Sweden; 2National Veterinary Institute,

Nor98 is a prion disease of old sheep and goats. This atypical form of
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
markers for phagocytic cells were conducted. The type of histological
and tissue reactions were evaluated. The types of PrPd deposition were
characterized. The cerebellar cortex was regularly affected, even though
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
PrPd was characteristic. It was morphologically and in distribution
with that of synaptophysin, suggesting that PrPd accumulates in the synaptic
structures. PrPd was also observed in the granule cell layer and in the
matter. ***The pathology features of Nor98 in the cerebellum of the affected
sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease
in humans.

Published online before print October 20, 2005

Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0502296102
Medical Sciences

A newly identified type of scrapie agent can naturally infect sheep with
resistant PrP genotypes

( sheep prion transgenic mice )

Annick Le Dur *, Vincent Béringue *, Olivier Andréoletti , Fabienne Reine *,
Thanh Lan Laï *, Thierry Baron , Bjørn Bratberg ¶, Jean-Luc Vilotte , Pierre
Sarradin **, Sylvie L. Benestad ¶, and Hubert Laude *
*Virologie Immunologie Moléculaires and Génétique Biochimique et
Cytogénétique, Institut National de la Recherche Agronomique, 78350
Jouy-en-Josas, France; Unité Mixte de Recherche, Institut National de la
Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions
Hôte Agent Pathogène, 31066 Toulouse, France; Agence Française de Sécurité
Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels,
69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut
National de la Recherche Agronomique, 37380 Nouzilly, France; and
¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway

Edited by Stanley B. Prusiner, University of California, San Francisco, CA,
and approved September 12, 2005 (received for review March 21, 2005)

Scrapie in small ruminants belongs to transmissible spongiform
encephalopathies (TSEs), or prion diseases, a family of fatal
neurodegenerative disorders that affect humans and animals and can transmit
within and between species by ingestion or inoculation. Conversion of the
host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a
misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission
and pathogenesis. The intensified surveillance of scrapie in the European
Union, together with the improvement of PrPSc detection techniques, has led
to the discovery of a growing number of so-called atypical scrapie cases.
These include clinical Nor98 cases first identified in Norwegian sheep on
the basis of unusual pathological and PrPSc molecular features and "cases"
that produced discordant responses in the rapid tests currently applied to
the large-scale random screening of slaughtered or fallen animals.
Worryingly, a substantial proportion of such cases involved sheep with PrP
genotypes known until now to confer natural resistance to conventional
scrapie. Here we report that both Nor98 and discordant cases, including
three sheep homozygous for the resistant PrPARR allele (A136R154R171),
efficiently transmitted the disease to transgenic mice expressing ovine PrP,
and that they shared unique biological and biochemical features upon
propagation in mice. These observations support the view that a truly
infectious TSE agent, unrecognized until recently, infects sheep and goat
flocks and may have important implications in terms of scrapie control and
public health.


Author contributions: H.L. designed research; A.L.D., V.B., O.A., F.R.,
T.L.L., J.-L.V., and H.L. performed research; T.B., B.B., P.S., and S.L.B.
contributed new reagents/analytic tools; V.B., O.A., and H.L. analyzed data;
and H.L. wrote the paper.

A.L.D. and V.B. contributed equally to this work.

To whom correspondence should be addressed.

Hubert Laude, E-mail:

Like lambs to the slaughter

31 March 2001

Debora MacKenzie

Magazine issue 2284

What if you can catch old-fashioned CJD by eating meat from a sheep infected
with scrapie?

FOUR years ago, Terry Singeltary watched his mother die horribly from a
degenerative brain disease. Doctors told him it was Alzheimer's, but
Singeltary was suspicious. The diagnosis didn't fit her violent symptoms,
and he demanded an autopsy. It showed she had died of sporadic
Creutzfeldt-Jakob disease.

Most doctors believe that sCJD is caused by a prion protein deforming by
chance into a killer. But Singeltary thinks otherwise. He is one of a number
of campaigners who say that some sCJD, like the variant CJD related to BSE,
is caused by eating meat from infected animals. Their suspicions have
focused on sheep carrying scrapie, a BSE-like disease that is widespread in
flocks across Europe and North America.

Now scientists in France have stumbled across new evidence that adds weight
to the campaigners' fears. To their complete surprise, the researchers found
that one strain of scrapie causes the same brain damage in ...

The complete article is 889 words long.

full text;


Adaptation of the bovine spongiform encephalopathy agent to primates and
comparison with Creutzfeldt- Jakob disease: Implications for human health
Corinne Ida Lasmézas*,, Jean-Guy Fournier*, Virginie Nouvel*, Hermann Boe*,
Domíníque Marcé*, François Lamoury*, Nicolas Kopp, Jean-Jacques Hauw§, James
Ironside¶, Moira Bruce, Dominique Dormont*, and Jean-Philippe Deslys*
* Commissariat à l'Energie Atomique, Service de Neurovirologie, Direction
des Sciences du Vivant/Département de Recherche Medicale, Centre de
Recherches du Service de Santé des Armées 60-68, Avenue du Général Leclerc,
BP 6, 92 265 Fontenay-aux-Roses Cedex, France; Hôpital Neurologique Pierre
Wertheimer, 59, Boulevard Pinel, 69003 Lyon, France; § Laboratoire de
Neuropathologie, Hôpital de la Salpêtrière, 83, Boulevard de l'Hôpital,
75013 Paris, France; ¶ Creutzfeldt-Jakob Disease Surveillance Unit, Western
General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; and
Institute for Animal Health, Neuropathogenesis Unit, West Mains Road,
Edinburgh EH9 3JF, United Kingdom

Edited by D. Carleton Gajdusek, Centre National de la Recherche
Scientifique, Gif-sur-Yvette, France, and approved December 7, 2000
(received for review October 16, 2000)


There is substantial scientific evidence to support the notion that bovine
spongiform encephalopathy (BSE) has contaminated human beings, causing
variant Creutzfeldt-Jakob disease (vCJD). This disease has raised concerns
about the possibility of an iatrogenic secondary transmission to humans,
because the biological properties of the primate-adapted BSE agent are
unknown. We show that (i) BSE can be transmitted from primate to primate by
intravenous route in 25 months, and (ii) an iatrogenic transmission of vCJD
to humans could be readily recognized pathologically, whether it occurs by
the central or peripheral route. Strain typing in mice demonstrates that the
BSE agent adapts to macaques in the same way as it does to humans and
confirms that the BSE agent is responsible for vCJD not only in the United
Kingdom but also in France. The agent responsible for French iatrogenic
growth hormone-linked CJD taken as a control is very different from vCJD but
is similar to that found in one case of sporadic CJD and one sheep scrapie
isolate. These data will be key in identifying the origin of human cases of
prion disease, including accidental vCJD transmission, and could provide
bases for vCJD risk assessment.

typical scrapie transmits to primates by there NON-FORCED ORAL CONSUMPTION ;


snip...full text ;


Saturday, April 12, 2008
Evidence of scrapie transmission via milk

Research articleS

Saturday, April 12, 2008

The sheep industry's scrapie eradication efforts. American Sheep Nor98-Like
Scrapie Found in the United States


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