Paper
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...
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
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.
Scrapie in Deer: Comparisons and Contrasts to Chronic Wasting Disease (CWD)
Justin J. Greenlee of the Virus and Prion Diseases Research Unit, National
Animal Disease Center, ARS, USDA, Ames, IA
snip...
This highlights the facts that
1) prior to the onset of clinical signs PrPSc is widely distributed in the
CNS and lymphoid tissues and
2) currently used diagnostic methods are sufficient to detect PrPSc prior
to the onset of clinical signs.
The results of this study suggest that there are many similarities in the
manifestation of CWD and scrapie in white-tailed deer 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 consistent with 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 white-tailed deer 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 scrapie by
IHC and WB. Tissues with PrPSc immunoreactivity included brain, tonsil,
retropharyngeal and mesenteric lymph nodes, hemal node, Peyer’s patches, and
spleen. While two WB patterns have been detected in brain regions of deer
inoculated by the natural route, unlike the IC inoculated deer, the pattern
similar to the scrapie inoculum predominates.
2011 Annual Report
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Location: Virus and Prion Research
Unit
2011 Annual Report
In Objective 1, Assess cross-species transmissibility of transmissible
spongiform encephalopathies (TSEs) in livestock and wildlife, numerous
experiments assessing the susceptibility of various TSEs in different host
species were conducted. Most notable is deer inoculated with scrapie, which
exhibits similarities to chronic wasting disease (CWD) in deer suggestive of
sheep scrapie as an origin of CWD.
snip...
4. Accomplishments
1. Deer inoculated with domestic isolates of sheep scrapie.
Scrapie-affected deer exhibit 2 different patterns of disease associated prion
protein. In some regions of the brain the pattern is much like that observed for
scrapie, while in others it is more like chronic wasting disease (CWD), the
transmissible spongiform encephalopathy typically associated with deer.
his work conducted by ARS scientists at the National Animal Disease Center,
Ames, IA suggests that an interspecies transmission of sheep scrapie to deer may
have been the origin of CWD. This is important for husbandry practices with both
captive deer, elk and sheep for farmers and ranchers attempting to keep their
herds and flocks free of CWD and scrapie.
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
snip...
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 ;
SEE MORE USAHA REPORTS HERE, 2012 NOT PUBLISHED YET...TSS
*** 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. ...
also, see where even decades back, the USDA had the same thought as they do
today with CWD, not their problem...see page 27 below as well, where USDA stated
back then, the same thing they stated in the state of Pennsylvania, not their
damn business, once they escape, and they said the same thing about CWD in
general back then ;
”The occurrence of CWD must be viewed against the contest of the locations
in which it occurred. It was an incidental and unwelcome complication of the
respective wildlife research programmes. Despite it’s subsequent recognition as
a new disease of cervids, therefore justifying direct investigation, no specific
research funding was forthcoming. The USDA veiwed it as a wildlife problem and
consequently not their province!” ...page 26.
Conclusions. During the pre-symptomatic stage of CWD infection and
throughout the course of disease deer may be shedding multiple LD50 doses per
day in their saliva. CWD prion shedding through saliva and excreta may account
for the unprecedented spread of this prion disease in nature. Acknowledgments.
Supported by NIH grant RO1-NS-061902 and grant D12ZO-045 from the Morris Animal
Foundation.
*** We conclude that TSE infectivity is likely to survive burial for long
time periods with minimal loss of infectivity and limited movement from the
original burial site. However PMCA results have shown that there is the
potential for rainwater to elute TSE related material from soil which could lead
to the contamination of a wider area. These experiments reinforce the importance
of risk assessment when disposing of TSE risk materials.
*** The results show that even highly diluted PrPSc can bind efficiently to
polypropylene, stainless steel, glass, wood and stone and propagate the
conversion of normal prion protein. For in vivo experiments, hamsters were ic
injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters,
inoculated with 263K-contaminated implants of all groups, developed typical
signs of prion disease, whereas control animals inoculated with non-contaminated
materials did not.
PRION 2014 CONFERENCE
CHRONIC WASTING DISEASE CWD
A FEW FINDINGS ;
Conclusions. To our knowledge, this is the first established experimental
model of CWD in TgSB3985. We found evidence for co-existence or divergence of
two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice.
Finally, we observed phenotypic differences between cervid-derived CWD and
CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway
to characterize these strains.
We conclude that TSE infectivity is likely to survive burial for long time
periods with minimal loss of infectivity and limited movement from the original
burial site. However PMCA results have shown that there is the potential for
rainwater to elute TSE related material from soil which could lead to the
contamination of a wider area. These experiments reinforce the importance of
risk assessment when disposing of TSE risk materials.
The results show that even highly diluted PrPSc can bind efficiently to
polypropylene, stainless steel, glass, wood and stone and propagate the
conversion of normal prion protein. For in vivo experiments, hamsters were ic
injected with implants incubated in 1% 263K-infected brain homogenate. Hamsters,
inoculated with 263K-contaminated implants of all groups, developed typical
signs of prion disease, whereas control animals inoculated with non-contaminated
materials did not.
Our data establish that meadow voles are permissive to CWD via peripheral
exposure route, suggesting they could serve as an environmental reservoir for
CWD. Additionally, our data are consistent with the hypothesis that at least two
strains of CWD circulate in naturally-infected cervid populations and provide
evidence that meadow voles are a useful tool for CWD strain typing.
Conclusion. CWD prions are shed in saliva and urine of infected deer as
early as 3 months post infection and throughout the subsequent >1.5 year
course of infection. In current work we are examining the relationship of
prionemia to excretion and the impact of excreted prion binding to surfaces and
particulates in the environment.
Conclusion. CWD prions (as inferred by prion seeding activity by RT-QuIC)
are shed in urine of infected deer as early as 6 months post inoculation and
throughout the subsequent disease course. Further studies are in progress
refining the real-time urinary prion assay sensitivity and we are examining more
closely the excretion time frame, magnitude, and sample variables in
relationship to inoculation route and prionemia in naturally and experimentally
CWD-infected cervids.
Conclusions. Our results suggested that the odds of infection for CWD is
likely controlled by areas that congregate deer thus increasing direct
transmission (deer-to-deer interactions) or indirect transmission
(deer-to-environment) by sharing or depositing infectious prion proteins in
these preferred habitats. Epidemiology of CWD in the eastern U.S. is likely
controlled by separate factors than found in the Midwestern and endemic areas
for CWD and can assist in performing more efficient surveillance efforts for the
region.
Conclusions. During the pre-symptomatic stage of CWD infection and
throughout the course of disease deer may be shedding multiple LD50 doses per
day in their saliva. CWD prion shedding through saliva and excreta may account
for the unprecedented spread of this prion disease in nature.
see full text and more ;
Monday, June 23, 2014
*** PRION 2014 CONFERENCE CHRONIC WASTING DISEASE CWD
*** Infectious agent of sheep scrapie may persist in the environment for at
least 16 years***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
New studies on the heat resistance of hamster-adapted scrapie agent:
Threshold survival after ashing at 600°C suggests an inorganic template of
replication
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel
Production
Detection of protease-resistant cervid prion protein in water from a
CWD-endemic area
A Quantitative Assessment of the Amount of Prion Diverted to Category 1
Materials and Wastewater During Processing
Rapid assessment of bovine spongiform encephalopathy prion inactivation by
heat treatment in yellow grease produced in the industrial manufacturing process
of meat and bone meals
Sunday, November 3, 2013
Environmental Impact Statements; Availability, etc.: Animal Carcass
Management [Docket No. APHIS-2013-0044]
Friday, October 17, 2014
Missouri Final action on Orders of Rule making Breeders and Big Game
Hunting Preserves
Saturday, October 18, 2014
Chronic wasting disease threatens Canadian agriculture, Alberta MLA
says
Thursday, October 23, 2014
FIRST CASE OF CHRONIC WASTING DISEASE CONFIRMED IN OHIO ON PRIVATE PRESERVE
Tuesday, October 21, 2014
Pennsylvania Department of Agriculture Tenth Pennsylvania Captive Deer
Tests Positive for Chronic Wasting Disease CWD TSE PRION DISEASE
Tuesday, October 07, 2014
Wisconsin white-tailed deer tested positive for CWD on a Richland County
breeding farm, and a case of CWD has been discovered on a Marathon County
hunting preserve
Thursday, October 02, 2014
IOWA TEST RESULTS FROM CAPTIVE DEER HERD WITH CHRONIC WASTING DISEASE
RELEASED 79.8 percent of the deer tested positive for the disease
Thursday, July 03, 2014
*** How Chronic Wasting Disease is affecting deer population and what’s the
risk to humans and pets?
Tuesday, July 01, 2014
*** CHRONIC WASTING DISEASE CWD TSE PRION DISEASE, GAME FARMS, AND
POTENTIAL RISK FACTORS THERE FROM
Saturday, October 25, 2014
118th USAHA Annual Meeting CWD and Captive Cerivds
IN THE UNITED STATES DISTRICT COURT FOR THE NORTHERN DISTRICT OF INDIANA
SOUTH BEND DIVISION UNITED STATES OF AMERICA, vs. RUSSELL G. BELLAR, Defendant.
___________________________
)))))))))
Cause No.: 3:04cr00068-AS South Bend, Indiana January 4, 2005 9:30 a.m.
TRANSCRIPT EXCERPT OF JURY TRIAL (TESTIMONY OF: RONNIE DUNN AND RUSTY CAMP)
BEFORE THE HONORABLE ALLEN SHARP
snip...
Ronnie Dunn Cross Examination
Q. Mr. Dunn, at one point I believe you told the federal agents that Mr.
Bellar told you that this was a private deer farm and shooting deer on that farm
was like slaughtering cattle; is that correct?
A. I don't know if I used the word "slaughter," but it was, yeah, like
that.
Q. You don't know if that was your word, "slaughtering cattle"?
A. I don't know that.
Q. Well, did he give you the idea of killing cattle?
A. Yes, it was the same principle.
snip...
see full text ;
BUCK FEVER
*** 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.
TSS
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