PENNSYLVANIA TWELVE MORE CASES OF CWD FOUND: STATE GEARS UP FOR ADDITIONAL CONTROL MEASURES
05/11/2016
TWELVE MORE CASES OF CWD IN PENNSYLVANIA: STATE GEARS UP FOR ADDITIONAL
CONTROL MEASURES
HARRISBURG, PA - The Pennsylvania Game Commission during 2015 found 12
additional white-tailed deer infected with chronic wasting disease (CWD) – all
in Disease Management Area 2 (DMA 2), located in southcentral
Pennsylvania.
DMA 2 is the only area of the state where CWD has been detected in
free-ranging deer.
The latest cases bring to 22 the total number of free-ranging deer found
with CWD within DMA 2 since 2012. This is the highest number of cases to be
found in a single year, and more than doubles the total number of CWD-positive
deer found in the wild in Pennsylvania.
These new cases have resulted in changes to DMA 2’s boundaries, increasing
the size of the DMA by more than 437 square miles. A map showing the latest
expansion to DMA 2 has been posted online at www.pgc.pa.gov and will be included
in the 2016-17 Pennsylvania Hunting & Trapping Digest that’s issued to
hunters at the time the buy their licenses. However, hunters are reminded that
future CWD cases could further impact DMA 2’s boundary, and the most up-to-date
maps always can be found at the Game Commission’s website.
Special rules regarding the hunting, transport and feeding of wild deer
apply within all DMAs, and are detailed in full online.
One of the new cases was found in a deer harvested by a hunter. It serves
as an example of why hunters need to be taking the DMA restrictions seriously.
The hunter in the case transported a buck that later tested positive for CWD
from DMA 2 to a deer processor far outside of the DMA, and the high-risk parts
went to a rendering plant.
Transporting a deer out of the DMA is illegal. By leaving behind those
parts with the highest-risk of transmitting CWD to other deer, hunters limit the
chances the disease will spread to new areas of the state. The hunter in this
case, which has been adjudicated, also failed to report the deer as required by
law.
Hunters need to be taking CWD seriously. To do otherwise, risks spreading
the disease to deer and elk in other parts of Pennsylvania. In the early stages
of infection, CWD tends to spread and increase very slowly in wild deer
populations. This might cause hunters to have a false sense of security, and
take the presence of the disease lightly.
In some areas of Wyoming and Wisconsin, more than 40 percent of deer and
elk tested have been positive for CWD. Arkansas first reported a CWD-positive
elk on Feb. 23. Follow-up sampling since then has found an additional 81
positive animals, and 23 percent of the deer and elk samples from the infected
area of northern Arkansas tested positive. It is thought that CWD might have
been present, but gone undetected in Arkansas for as long as 10 years.
“This is the one disease that has the potential to drastically change deer
hunting as we know it,” said Game Commission Wildlife Management Director Wayne
Laroche.
Statewide, a total of 5,645 road-killed, hunter-harvested and suspected
infected deer were tested for CWD in Pennsylvania during 2015. The Game
Commission stepped up sampling efforts within DMA 2 during 2015 in an attempt to
enhance monitoring efforts and to estimate a prevalence level of CWD within
townships representing the core area of infection within DMA 2. A total of 1,602
samples were collected from deer within DMA 2. Twelve, or 0.75 percent of these,
tested CWD positive.
The good news is the prevalence level of CWD within DMA2 seems to remain at
a relatively low level. But, unless additional control measures are implemented,
the infection rate is certain to increase.
The Game Commission for the 2016-17 seasons has allocated 14,500 DMA 2
Antlerless Deer Permits, in addition to antlerless licenses allocated for the
WMUs partially within DMA 2. The permits must be purchased online or through
mail-in application, and they go on sale at the same time antlerless licenses,
July 11. More information on DMA 2 Permits can be found on the CWD page of the
Game Commission’s website.
However, controlling total deer numbers only seems to slow the spread of
the disease.
Wisconsin’s experience clearly demonstrates that controlling total deer
numbers alone will not stop the disease from increasing. Illinois, which has
employed a targeted deer-removal strategy at locations where positive animals
have been found, has managed to hold prevalence at a low level since finding CWD
in 2002. Targeted removal in areas where the disease is most prevalent is a more
surgical strategy to limiting the spread of CWD.
Along with Illinois, Wisconsin also found CWD in 2002. Wisconsin began with
an aggressive population-reduction strategy until being shut down by public
pressure. While it is believed that the prevalence level in Illinois now remains
at near 1 percent in the infected area, Wisconsin’s prevalence rate reportedly
has climbed to 9.4 percent.
Like Illinois, Wisconsin now is considering the use of a targeted-removal
method.
The Game Commission hopes to act sooner rather than later to put in place
active control measures to stop the spread and growth of the disease within the
Commonwealth. These measures may involve targeted removal of deer at locations
where CWD-positive animals have been found. Discussion and planning are
currently underway; details will provided once the planning process is further
along.
“One thing we know is we will not be successful without the support of deer
hunters and the general public,” Laroche said. “If we fail to develop and
implement an effective control program, we risk the future of deer hunting along
with all of the social and economic benefits that wild white-tailed deer and elk
provide to the people of Pennsylvania.”
It has been estimated that deer hunting alone adds more than $1 billion a
year to Pennsylvania’s economy. The tradition and social value that whitetails
and elk provide to Pennsylvanians is incalculable.
MEDIA CONTACT: Travis Lau - 717-705-6541
# # #
PA CWD Management Area DMA 2
Friday, February 26, 2016
Pennsylvania Monitoring the Growing Threat of Chronic Wasting Disease CWD
TSE Prion
2015
Saturday, November 07, 2015
PENNSYLVANIA CHRONIC WASTING DISEASE CWD TSE PRION RULES EXPAND
Saturday, November 07, 2015
Pennsylvania 2015 September Minutes CWD Urine Scents
Sunday, October 18, 2015
Pennsylvania Game Commission Law and Law Makers CWD TSE PRION Bans
Singeltary 2002 from speaking A smelly situation UPDATED 2015
Tuesday, May 05, 2015
Pennsylvania CWD DETECTED IN SIX MORE FREE-RANGING DEER Disease Management
Area 2 again expanded due to new cases Release #030-15
**********2014 PENNSYLVANIA CWD**********
Tuesday, October 21, 2014
Pennsylvania Department of Agriculture Tenth Pennsylvania Captive Deer
Tests Positive for Chronic Wasting Disease CWD TSE PRION DISEASE
Sunday, July 13, 2014
Louisiana deer mystery unleashes litigation 6 does still missing from CWD
index herd in Pennsylvania Great Escape
Saturday, June 29, 2013
PENNSYLVANIA CAPTIVE CWD INDEX HERD MATE YELLOW *47 STILL RUNNING LOOSE IN
INDIANA, YELLOW NUMBER 2 STILL MISSING, AND OTHERS ON THE RUN STILL IN LOUISIANA
Tuesday, June 11, 2013
*** CWD GONE WILD, More cervid escapees from more shooting pens on the
loose in Pennsylvania
Tuesday, May 28, 2013
Chronic Wasting Disease CWD quarantine Louisiana via CWD index herd
Pennsylvania Update May 28, 2013
*** 6 doe from Pennsylvania CWD index herd still on the loose in Louisiana,
quarantine began on October 18, 2012, still ongoing, Lake Charles premises.
Sunday, January 06, 2013
USDA TO PGC ONCE CAPTIVES ESCAPE
*** "it‘s no longer its business.”
”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.
Wednesday, November 14, 2012
PENNSYLVANIA 2012 THE GREAT ESCAPE OF CWD INVESTIGATION MOVES INTO
LOUISIANA and INDIANA
Tuesday, October 23, 2012
PA Captive deer from CWD-positive farm roaming free
Thursday, October 11, 2012
Pennsylvania Confirms First Case CWD Adams County Captive Deer Tests
Positive
Wednesday, February 11, 2015
World Class Whitetails quarantined CWD deer Daniel M. Yoder charged with
two counts of tampering with evidence
Cervid to human prion transmission
Kong, Qingzhong
Case Western Reserve University, Cleveland, OH, United States
Abstract
Prion disease is transmissible and invariably fatal. Chronic wasting
disease (CWD) is the prion disease affecting deer, elk and moose, and it is a
widespread and expanding epidemic affecting 22 US States and 2 Canadian
provinces so far. CWD poses the most serious zoonotic prion transmission risks
in North America because of huge venison consumption (>6 million deer/elk
hunted and consumed annually in the USA alone), significant prion infectivity in
muscles and other tissues/fluids from CWD-affected cervids, and usually high
levels of individual exposure to CWD resulting from consumption of the affected
animal among often just family and friends. However, we still do not know
whether CWD prions can infect humans in the brain or peripheral tissues or
whether clinical/asymptomatic CWD zoonosis has already occurred, and we have no
essays to reliably detect CWD infection in humans. We hypothesize that:
(1) The classic CWD prion strain can infect humans at low levels in the
brain and peripheral lymphoid tissues;
(2) The cervid-to-human transmission barrier is dependent on the cervid
prion strain and influenced by the host (human) prion protein (PrP) primary
sequence;
(3) Reliable essays can be established to detect CWD infection in
humans;and
(4) CWD transmission to humans has already occurred. We will test these
hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in
vitro approaches.
Aim 1 will prove that the classical CWD strain may infect humans in brain
or peripheral lymphoid tissues at low levels by conducting systemic bioassays in
a set of "humanized" Tg mouse lines expressing common human PrP variants using a
number of CWD isolates at varying doses and routes. Experimental "human CWD"
samples will also be generated for Aim 3.
Aim 2 will test the hypothesis that the cervid-to-human prion transmission
barrier is dependent on prion strain and influenced by the host (human) PrP
sequence by examining and comparing the transmission efficiency and phenotypes
of several atypical/unusual CWD isolates/strains as well as a few prion strains
from other species that have adapted to cervid PrP sequence, utilizing the same
panel of humanized Tg mouse lines as in Aim 1.
Aim 3 will establish reliable essays for detection and surveillance of CWD
infection in humans by examining in details the clinical, pathological,
biochemical and in vitro seeding properties of existing and future experimental
"human CWD" samples generated from Aims 1-2 and compare them with those of
common sporadic human Creutzfeldt-Jakob disease (sCJD) prions.
Aim 4 will attempt to detect clinical CWD-affected human cases by examining
a significant number of brain samples from prion-affected human subjects in the
USA and Canada who have consumed venison from CWD-endemic areas utilizing the
criteria and essays established in Aim 3. The findings from this proposal will
greatly advance our understandings on the potential and characteristics of
cervid prion transmission in humans, establish reliable essays for CWD zoonosis
and potentially discover the first case(s) of CWD infection in humans.
Public Health Relevance There are significant and increasing human exposure
to cervid prions because chronic wasting disease (CWD, a widespread and highly
infectious prion disease among deer and elk in North America) continues
spreading and consumption of venison remains popular, but our understanding on
cervid-to-human prion transmission is still very limited, raising public health
concerns. This proposal aims to define the zoonotic risks of cervid prions and
set up and apply essays to detect CWD zoonosis using mouse models and in vitro
methods. The findings will greatly expand our knowledge on the potentials and
characteristics of cervid prion transmission in humans, establish reliable
essays for such infections and may discover the first case(s) of CWD infection
in humans.
Funding Agency Agency National Institute of Health (NIH)
Institute National Institute of Neurological Disorders and Stroke (NINDS)
Type Research Project (R01)
Project # 1R01NS088604-01A1
Application # 9037884
Study Section Cellular and Molecular Biology of Neurodegeneration Study
Section (CMND)
Program Officer Wong, May
Project Start 2015-09-30
Project End 2019-07-31
Budget Start 2015-09-30
Budget End 2016-07-31
Support Year 1
Fiscal Year 2015
Total Cost $337,507
Indirect Cost $118,756
Institution
Name Case Western Reserve University
Department Pathology
Type Schools of Medicine
DUNS # 077758407
City Cleveland
State OH
Country United States
Zip Code 44106
===========================================================
We hypothesize that:
(1) The classic CWD prion strain can infect humans at low levels in the
brain and peripheral lymphoid tissues;
(2) The cervid-to-human transmission barrier is dependent on the cervid
prion strain and influenced by the host (human) prion protein (PrP) primary
sequence;
(3) Reliable essays can be established to detect CWD infection in
humans;and
(4) *** CWD transmission to humans has already occurred. *** We will test
these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary
in vitro approaches.
============================================================
Key Molecular Mechanisms of TSEs
Zabel, Mark D.
Colorado State University-Fort Collins, Fort Collins, CO, United States
Abstract Prion diseases, or transmissible spongiform encephalopathies (TSEs),
are fatal neurodegenerative diseases affecting humans, cervids, bovids, and
ovids. The absolute requirement of PrPC expression to generate prion diseases
and the lack of instructional nucleic acid define prions as unique infectious
agents. Prions exhibit species-specific tropism, inferring that unique prion
strains exist that preferentially infct certain host species and confront
transmission barriers to heterologous host species. However, transmission
barriers are not absolute. Scientific consensus agrees that the sheep TSE
scrapie probably breached the transmission barrier to cattle causing bovine
spongiform encephalopathy that subsequently breached the human transmission
barrier and likely caused several hundred deaths by a new-variant form of the
human TSE Creutzfeldt-Jakob disease in the UK and Europe. The impact to human
health, emotion and economies can still be felt in areas like farming, blood and
organ donations and the threat of a latent TSE epidemic. This precedent raises
the real possibility of other TSEs, like chronic wasting disease of cervids,
overcoming similar human transmission barriers. A groundbreaking discovery made
last year revealed that mice infected with heterologous prion strains facing
significant transmission barriers replicated prions far more readily in spleens
than brains6. Furthermore, these splenic prions exhibited weakened transmission
barriers and expanded host ranges compared to neurogenic prions. These data
question conventional wisdom of avoiding neural tissue to avoid prion
xenotransmission, when more promiscuous prions may lurk in extraneural tissues.
Data derived from work previously funded by NIH demonstrate that Complement
receptors CD21/35 bind prions and high density PrPC and differentially impact
prion disease depending on the prion isolate or strain used. Recent advances in
live animal and whole organ imaging have led us to generate preliminary data to
support novel, innovative approaches to assessing prion capture and transport.
We plan to test our unifying hypothesis for this proposal that CD21/35 control
the processes of peripheral prion capture, transport, strain selection and
xenotransmission in the following specific aims. 1. Assess the role of CD21/35
in splenic prion strain selection and host range expansion. 2. Determine whether
CD21/35 and C1q differentially bind distinct prion strains 3. Monitor the
effects of CD21/35 on prion trafficking in real time and space 4. Assess the
role of CD21/35 in incunabular prion trafficking
Public Health Relevance Transmissible spongiform encephalopathies, or prion
diseases, are devastating illnesses that greatly impact public health,
agriculture and wildlife in North America and around the world. The impact to
human health, emotion and economies can still be felt in areas like farming,
blood and organ donations and the threat of a latent TSE epidemic. This
precedent raises the real possibility of other TSEs, like chronic wasting
disease (CWD) of cervids, overcoming similar human transmission barriers. Early
this year Canada reported its first case of BSE in over a decade audits first
case of CWD in farmed elk in three years, underscoring the need for continued
vigilance and research. Identifying mechanisms of transmission and zoonoses
remains an extremely important and intense area of research that will benefit
human and other animal populations.
Funding Agency Agency National Institute of Health (NIH)
Institute National Institute of Allergy and Infectious Diseases (NIAID)
Type High Priority, Short Term Project Award (R56)
Project # 1R56AI122273-01A1
Application # 9211114
Study Section Cellular and Molecular Biology of Neurodegeneration Study
Section (CMND)
Program Officer Beisel, Christopher E
Project Start 2016-02-16
Project End 2017-01-31
Budget Start 2016-02-16
Budget End 2017-01-31
Support Year 1
Fiscal Year 2016
Total Cost
Indirect Cost Institution Name Colorado State University-Fort Collins
Department Microbiology/Immun/Virology
Type Schools of Veterinary Medicine
DUNS # 785979618 City Fort Collins
State CO
Country United States
Zip Code 80523
PMCA Detection of CWD Infection in Cervid and Non-Cervid Species
Hoover, Edward Arthur
Colorado State University-Fort Collins, Fort Collins, CO, United States
Abstract Chronic wasting disease (CWD) of deer and elk is an emerging highly
transmissible prion disease now recognized in 18 States, 2 Canadian provinces,
and Korea. We have shown that Infected deer harbor and shed high levels of
infectious prions in saliva, blood, urine, and feces, and in the tissues
generating those body fluids and excreta, thereby leading to facile transmission
by direct contact and environmental contamination. We have also shown that CWD
can infect some non-cervid species, thus the potential risk CWD represents to
domestic animal species and to humans remains unknown. Whether prions borne in
blood, saliva, nasal fluids, milk, or excreta are generated or modified in the
proximate peripheral tissue sites, may differ in subtle ways from those
generated in brain, or may be adapted for mucosal infection remain open
questions. The increasing parallels in the pathogenesis between prion diseases
and human neurodegenerative conditions, such as Alzheimer's and Parkinson's
diseases, add relevance to CWD as a transmissible protein misfolding disease.
The overall goal of this work is to elucidate the process of CWD prion
transmission from mucosal secretory and excretory tissue sites by addressing
these questions: (a) What are the kinetics and magnitude of CWD prion shedding
post-exposure? (b) Are excreted prions biochemically distinct, or not, from
those in the CNS? (c) Are peripheral epithelial or CNS tissues, or both, the
source of excreted prions? and (d) Are excreted prions adapted for horizontal
transmission via natural/trans-mucosal routes? The specific aims of this
proposal are: (1) To determine the onset and consistency of CWD prion shedding
in deer and cervidized mice; (2); To compare the biochemical and biophysical
properties of excretory vs. CNS prions; (3) To determine the capacity of
peripheral tissues to support replication of CWD prions; (4) To determine the
protease- sensitive infectious fraction of excreted vs. CNS prions; and (5) To
compare the mucosal infectivity of excretory vs. CNS prions. Understanding the
mechanisms that enable efficient prion dissemination and shedding will help
elucidate how horizontally transmissible prions evolve and succeed, and is the
basis of this proposal. Understanding how infectious misfolded proteins (prions)
are generated, trafficked, shed, and transmitted will aid in preventing,
treating, and managing the risks associated with these agents and the diseases
they cause.
Public Health Relevance Chronic wasting disease (CWD) of deer and elk is an
emergent highly transmissible prion disease now recognized throughout the USA as
well as in Canada and Korea. We have shown that infected deer harbor and shed
high levels of infectious prions in saliva, blood, urine, and feces thereby
leading to transmission by direct contact and environmental contamination. In
that our studies have also shown that CWD can infect some non-cervid species,
the potential risk CWD may represents to domestic animal species and humans
remains unknown. The increasing parallels in the development of major human
neurodegenerative conditions, such as Alzheimer's and Parkinson's diseases, and
prion diseases add relevance to CWD as a model of a transmissible protein
misfolding disease. Understanding how infectious misfolded proteins (prions) are
generated and transmitted will aid in interrupting, treating, and managing the
risks associated with these agents and the diseases they cause.
Funding Agency Agency National Institute of Health (NIH)
Institute National Institute of Neurological Disorders and Stroke (NINDS)
Type Research Project (R01)
Project # 4R01NS061902-07
Application # 9010980
Study Section Cellular and Molecular Biology of Neurodegeneration Study
Section (CMND)
Program Officer Wong, May Project Start 2009-09-30
Project End 2018-02-28
Budget Start 2016-03-01
Budget End 2017-02-28
Support Year 7
Fiscal Year 2016
Total Cost $409,868
Indirect Cost $134,234 Institution Name Colorado State University-Fort
Collins
Department Microbiology/Immun/Virology
Type Schools of Veterinary Medicine
DUNS # 785979618 City Fort Collins
State CO
Country United States
Zip Code 80523
Zoonotic Potential of CWD Prions: An Update
Ignazio Cali1, Liuting Qing1, Jue Yuan1, Shenghai Huang2, Diane Kofskey1,3,
Nicholas Maurer1, Debbie McKenzie4, Jiri Safar1,3,5, Wenquan Zou1,3,5,6,
Pierluigi Gambetti1, Qingzhong Kong1,5,6
1Department of Pathology, 3National Prion Disease Pathology Surveillance
Center, 5Department of Neurology, 6National Center for Regenerative Medicine,
Case Western Reserve University, Cleveland, OH 44106, USA.
4Department of Biological Sciences and Center for Prions and Protein
Folding Diseases, University of Alberta, Edmonton, Alberta, Canada,
2Encore Health Resources, 1331 Lamar St, Houston, TX 77010
Chronic wasting disease (CWD) is a widespread and highly transmissible
prion disease in free-ranging and captive cervid species in North America. The
zoonotic potential of CWD prions is a serious public health concern, but the
susceptibility of human CNS and peripheral organs to CWD prions remains largely
unresolved. We reported earlier that peripheral and CNS infections were detected
in transgenic mice expressing human PrP129M or PrP129V. Here we will present an
update on this project, including evidence for strain dependence and influence
of cervid PrP polymorphisms on CWD zoonosis as well as the characteristics of
experimental human CWD prions.
PRION 2016 TOKYO
In Conjunction with Asia Pacific Prion Symposium 2016
PRION 2016 Tokyo
Prion 2016
Prion 2016
Purchase options Price * Issue Purchase USD 198.00
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a.
Vincent Beringue c. Patricia Aguilar a,
Natalia Fernandez-Borges a. and Alba Marin-Moreno a
"Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos,
Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT.
Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas.
France
Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated
bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD)
disease in human. To date, BSE agent is the only recognized zoonotic prion.
Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that
have been circulating for centuries in farmed ruminants there is no apparent
epidemiological link between exposure to ruminant products and the occurrence of
other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD).
However, the zoonotic potential of the diversity of circulating TSE agents has
never been systematically assessed. The major issue in experimental assessment
of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the
biological phenomenon that limits TSE agents’ propagation from a species to
another. In the last decade, mice genetically engineered to express normal forms
of the human prion protein has proved essential in studying human prions
pathogenesis and modeling the capacity of TSEs to cross the human species
barrier.
To assess the zoonotic potential of prions circulating in farmed ruminants,
we study their transmission ability in transgenic mice expressing human PrPC
(HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC
(129Met or 129Val) are used to determine the role of the Met129Val dimorphism in
susceptibility/resistance to the different agents.
These transmission experiments confirm the ability of BSE prions to
propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be
susceptible to BSE in sheep or goat to a greater degree than the BSE agent in
cattle and that these agents can convey molecular properties and
neuropathological indistinguishable from vCJD. However homozygous 129V mice are
resistant to all tested BSE derived prions independently of the originating
species suggesting a higher transmission barrier for 129V-PrP variant.
Transmission data also revealed that several scrapie prions propagate in
HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the
efficiency of transmission at primary passage was low, subsequent passages
resulted in a highly virulent prion disease in both Met129 and Val129 mice.
Transmission of the different scrapie isolates in these mice leads to the
emergence of prion strain phenotypes that showed similar characteristics to
those displayed by MM1 or VV2 sCJD prion. These results demonstrate that scrapie
prions have a zoonotic potential and raise new questions about the possible link
between animal and human prions.
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL
THE WRONG PLACES $$$
*** 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).***
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.
==================
***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
Conversely, FSE maintained sufficient BSE characteristics to more
efficiently convert bovine rPrP than feline rPrP. 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.
================
***This insinuates that, at the level of protein:protein interactions, the
barrier preventing transmission of CWD to humans is less robust than previously
estimated.***
================
*** PRICE OF CWD TSE PRION POKER GOES UP 2014 ***
Transmissible Spongiform Encephalopathy TSE PRION update January 2, 2014
*** chronic wasting disease, there was no absolute barrier to conversion of
the human prion protein.
*** Furthermore, the form of human PrPres produced in this in vitro assay
when seeded with CWD, resembles that found in the most common human prion
disease, namely sCJD of the MM1 subtype.
*** 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.
Chronic Wasting Disease and Potential Transmission to Humans
Ermias D. Belay,* Ryan A. Maddox,* Elizabeth S. Williams,† Michael W.
Miller,‡ Pierluigi Gambetti,§ and Lawrence B. Schonberger*
Chronic wasting disease (CWD) of deer and elk is endemic in a tri-corner
area of Colorado, Wyoming, and Nebraska, and new foci of CWD have been detected
in other parts of the United States. Although detection in some areas may be
related to increased surveillance, introduction of CWD due to translocation or
natural migration of animals may account for some new foci of infection.
Increasing spread of CWD has raised concerns about the potential for increasing
human exposure to the CWD agent. The foodborne transmission of bovine spongiform
encephalopathy to humans indicates that the species barrier may not completely
protect humans from animal prion diseases. Conversion of human prion protein by
CWDassociated prions has been demonstrated in an in vitro cellfree experiment,
but limited investigations have not identified strong evidence for CWD
transmission to humans. More epidemiologic and laboratory studies are needed to
monitor the possibility of such transmissions.
Conclusions
The lack of evidence of a link between CWD transmission and unusual cases
of CJD, despite several epidemiologic investigations, and the absence of an
increase in CJD incidence in Colorado and Wyoming suggest that the risk, if any,
of transmission of CWD to humans is low. Although the in vitro studies
indicating inefficient conversion of human prion protein by CWD-associated
prions raise the possibility of low-level transmission of CWD to humans, no
human cases of prion disease with strong evidence of a link with CWD have been
identified. However, the transmission of BSE to humans and the resulting vCJD
indicate that, provided sufficient exposure, the species barrier may not
completely protect humans from animal prion diseases. Because CWD has occurred
in a limited geographic area for decades, an adequate number of people may not
have been exposed to the CWD agent to result in a clinically recognizable human
disease. The level and frequency of human exposure to the CWD agent may increase
with the spread of CWD in the United States. Because the number of studies
seeking evidence for CWD transmission to humans is limited, more epidemiologic
and laboratory studies should be conducted to monitor the possibility of such
transmissions. Studies involving transgenic mice expressing human and cervid
prion protein are in progress to further assess the potential for the CWD agent
to cause human disease. Epidemiologic studies have also been initiated to
identify human cases of prion disease among persons with an increased risk for
exposure to potentially CWD-infected deer or elk meat (47). If such cases are
identified, laboratory data showing similarities of the etiologic agent to that
of the CWD agent would strengthen the conclusion for a causal link. Surveillance
for human prion diseases, particularly in areas where CWD has been detected,
remains important to effectively monitor the possible transmission of CWD to
humans. Because of the long incubation period associated with prion diseases,
convincing negative results from epidemiologic and experimental laboratory
studies would likely require years of follow-up. In the meantime, to minimize
the risk for exposure to the CWD agent, hunters should consult with their state
wildlife agencies to identify areas where CWD occurs and continue to follow
advice provided by public health and wildlife agencies. Hunters should avoid
eating meat from deer and elk that look sick or test positive for CWD. They
should wear gloves when field-dressing carcasses, boneout the meat from the
animal, and minimize handling of brain and spinal cord tissues. As a precaution,
hunters should avoid eating deer and elk tissues known to harbor the CWD agent
(e.g., brain, spinal cord, eyes, spleen, tonsils, lymph nodes) from areas where
CWD has been identified.
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 ;
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 ***
Envt.07:
Pathological Prion Protein (PrPTSE) in Skeletal Muscles of Farmed and Free
Ranging White-Tailed Deer Infected with Chronic Wasting Disease
***The presence and seeding activity of PrPTSE in skeletal muscle from
CWD-infected cervids suggests prevention of such tissue in the human diet as a
precautionary measure for food safety, pending on further clarification of
whether CWD may be transmissible to humans.
Prions in Skeletal Muscles of Deer with Chronic Wasting Disease Rachel C.
Angers1,*, Shawn R. Browning1,*,†, Tanya S. Seward2, Christina J. Sigurdson4,‡,
Michael W. Miller5, Edward A. Hoover4, Glenn C. Telling1,2,3,§ snip...
Abstract The emergence of chronic wasting disease (CWD) in deer and elk in
an increasingly wide geographic area, as well as the interspecies transmission
of bovine spongiform encephalopathy to humans in the form of variant Creutzfeldt
Jakob disease, have raised concerns about the zoonotic potential of CWD. Because
meat consumption is the most likely means of exposure, it is important to
determine whether skeletal muscle of diseased cervids contains prion
infectivity. Here bioassays in transgenic mice expressing cervid prion protein
revealed the presence of infectious prions in skeletal muscles of CWD-infected
deer, demonstrating that humans consuming or handling meat from CWD-infected
deer are at risk to prion exposure.
***********CJD REPORT 1994 increased risk for consumption of veal and
venison and lamb***********
CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL
REPORT AUGUST 1994
Consumption of venison and veal was much less widespread among both cases
and controls. For both of these meats there was evidence of a trend with
increasing frequency of consumption being associated with increasing risk of
CJD. (not nvCJD, but sporadic CJD...tss)
These associations were largely unchanged when attention was restricted to
pairs with data obtained from relatives. ...
Table 9 presents the results of an analysis of these data.
There is STRONG evidence of an association between ‘’regular’’ veal eating
and risk of CJD (p = .0.01).
Individuals reported to eat veal on average at least once a year appear to
be at 13 TIMES THE RISK of individuals who have never eaten veal.
There is, however, a very wide confidence interval around this estimate.
There is no strong evidence that eating veal less than once per year is
associated with increased risk of CJD (p = 0.51).
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).
There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY
OF LAMB EATING (p = 0.02).
The evidence for such an association between beef eating and CJD is weaker
(p = 0.14). When only controls for whom a relative was interviewed are included,
this evidence becomes a little STRONGER (p = 0.08).
snip...
It was found that when veal was included in the model with another
exposure, the association between veal and CJD remained statistically
significant (p = < 0.05 for all exposures), while the other exposures
ceased to be statistically significant (p = > 0.05).
snip...
In conclusion, an analysis of dietary histories revealed statistical
associations between various meats/animal products and INCREASED RISK OF CJD.
When some account was taken of possible confounding, the association between
VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS
STATISTICALLY. ...
snip...
In the study in the USA, a range of foodstuffs were associated with an
increased risk of CJD, including liver consumption which was associated with an
apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3
studies in relation to this particular dietary factor, the risk of liver
consumption became non-significant with an odds ratio of 1.2 (PERSONAL
COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)
snip...see full report ;
CJD9/10022
October 1994
Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge
Spencers Lane BerksWell Coventry CV7 7BZ
Dear Mr Elmhirst,
CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT
Thank you for your recent letter concerning the publication of the third
annual report from the CJD Surveillance Unit. I am sorry that you are
dissatisfied with the way in which this report was published.
The Surveillance Unit is a completely independant outside body and the
Department of Health is committed to publishing their reports as soon as they
become available. In the circumstances it is not the practice to circulate the
report for comment since the findings of the report would not be amended. In
future we can ensure that the British Deer Farmers Association receives a copy
of the report in advance of publication.
The Chief Medical Officer has undertaken to keep the public fully informed
of the results of any research in respect of CJD. This report was entirely the
work of the unit and was produced completely independantly of the the
Department.
The statistical results reqarding the consumption of venison was put into
perspective in the body of the report and was not mentioned at all in the press
release. Media attention regarding this report was low key but gave a realistic
presentation of the statistical findings of the Unit. This approach to
publication was successful in that consumption of venison was highlighted only
once by the media ie. in the News at one television proqramme.
I believe that a further statement about the report, or indeed statistical
links between CJD and consumption of venison, would increase, and quite possibly
give damaging credence, to the whole issue. From the low key media reports of
which I am aware it seems unlikely that venison consumption will suffer
adversely, if at all.
http://web.archive.org/web/20030511010117/http://www.bseinquiry.gov.uk/files/yb/1994/10/00003001.pdf
*** 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).***
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, Valerie 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 long 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 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.
==============
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.
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
”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.
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. ...
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...
LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL
THE WRONG PLACES $$$
*** 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).***
Saturday, May 30, 2015
PRION 2015 ORAL AND POSTER CONGRESSIONAL ABSTRACTS
Wednesday, June 10, 2015
Zoonotic Potential of CWD Prions LATE-BREAKING ABSTRACTS
2015 PDA Virus & TSE Safety Forum Meeting Report
>>>Recently transmission of prions from blood of patients with
sporadic CJD to humanized mice could be demonstrated.<<<
>>>Further-on, urine samples of a control population (normal and
neurological population) showed no signal in the study; *** however, in samples
from patients with sporadic CJD and vCJD, a signal was detected in both patient
populations.<<<
Meeting Report: 2015 PDA Virus & TSE Safety Forum
Monday, May 09, 2016
A comparison of classical and H-type bovine spongiform encephalopathy
associated with E211K prion protein polymorphism in wild type and EK211 cattle
following intracranial inoculation
Sunday, May 08, 2016
WISCONSIN CHRONIC WASTING DISEASE CWD TSE PRION SPIRALING FURTHER INTO THE
ABYSS UPDATE
Friday, April 22, 2016
COLORADO CHRONIC WASTING DISEASE CWD TSE PRION SURVEILLANCE AND TESTING
PROGRAM IS MINIMAL AND LIMITED
Tuesday, May 03, 2016
Arkansas Chronic Wasting Disease CWD TSE Prion and Elk Restoration Project
and Hunkering Down in the BSE Situation Room USDA 1998
Wednesday, April 27, 2016
WYOMING GAME AND FISH DEPARTMENT CHRONIC WASTING DISEASE MANAGEMENT PLAN
APRIL 22, 2016
Friday, April 22, 2016
Missouri MDC finds seven new cases of ChronicWasting Disease CWD during
past‐season testing
Wednesday, April 20, 2016
UTAH CHRONIC WASTING DISEASE CWD TSE PRION SURVEILLANCE AND TESTING PROGRAM
70 mule deer and two elk have tested positive
KANSAS CWD CASES ALARMING
Wednesday, March 02, 2016 Kansas Chronic Wasting Disease CWD TSE Prion 52
cases 2015 updated report 'ALARMING'
Tuesday, February 02, 2016
Illinois six out of 19 deer samples tested positive for CWD in the Oswego
zone of Kendall County
Tuesday, April 12, 2016
*** The first detection of Chronic Wasting Disease (CWD) in Europe
***
Friday, April 22, 2016
Texas Scrapie Confirmed in a Hartley County Sheep where CWD was detected in
a Mule Deer
Wednesday, May 04, 2016
TPWD proposes the repeal of §§65.90 -65.94 and new §§65.90 -65.99
Concerning Chronic Wasting Disease - Movement of Deer Singeltary Comment
Submission
Saturday, April 02, 2016
TEXAS TAHC BREAKS IT'S SILENCE WITH TWO MORE CASES CWD CAPTIVE DEER
BRINGING TOTAL TO 10 CAPTIVES REPORTED TO DATE
Friday, February 26, 2016
TEXAS Hartley County Mule Deer Tests Positive for Chronic Wasting Disease
CWD TSE Prion
SEE UPDATE ON CWD OUTBREAK IN OTHER STATES USA
Thursday, March 31, 2016
*** Chronic Wasting Disease CWD TSE Prion Roundup USA 2016 ***
Saturday, April 16, 2016
APHIS [Docket No. APHIS-2016-0029] Secretary's Advisory Committee on Animal
Health; Meeting May 2, 2016, and June 16, 2016 Singeltary Submission
Sunday, May 1, 2016
Center for Biologics Evaluation and Research 25th Meeting of: The
Transmissible Spongiform Encephalopathies Advisory Committee June 1, 2015
Transcript
AND DRUG ADMINISTRATION
Tuesday, May 10, 2016
Accessing transmissibility and diagnostic marker of skin prions
Terry S. Singeltary Sr.
Wednesday, May 11, 2016
CERVID TO HUMAN PRION TRANSMISSION
Thursday, April 07, 2016
What is the risk of chronic wasting disease being introduced into Great
Britain? An updated Qualitative Risk Assessment March 2016
Sheep and cattle may be exposed to CWD via common grazing areas with
affected deer but so far, appear to be poorly susceptible to mule deer CWD
(Sigurdson, 2008).
***In contrast, cattle are highly susceptible to white-tailed deer CWD and
mule deer CWD in experimental conditions but no natural CWD infections in cattle
have been reported (Sigurdson, 2008; Hamir et al., 2006). It is not known how
susceptible humans are to CWD but given that the prion can be present in muscle,
it is likely that humans have been exposed to the agent via consumption of
venison (Sigurdson, 2008). Initial experimental research, however, suggests that
human susceptibility to CWD is low and there may be a robust species barrier for
CWD transmission to humans (Sigurdson, 2008). It is apparent, though, that CWD
is affecting wild and farmed cervid populations in endemic areas with some deer
populations decreasing as a result.
snip...
For the purpose of the qualitative risk assessment developed here it is
necessary to estimate the probability that a 30-ml bottle of lure contains urine
from an infected deer. This requires an estimate of the proportion of deer herds
in the USA which are infected with CWD together with the within herd prevalence.
The distribution map of CWD in US shows it is present mainly in central
states (Figure 1). However, Virginia in the east of the country has recorded
seven recent cases of CWD (Anon 2015a). Some US manufacturers claim to take
steps to prevent urine being taken from infected animals eg by sourcing from
farms where the deer are randomly tested for CWD (Anon 2015a). However, if
disease is already present and testing is not carried out regularly, captive
populations are not necessarily disease free (Strausser 2014). Urine-based deer
lures have been known to be collected from domestic white-tailed deer herds and
therefore there is a recognised risk. This is reflected by 6 US States which
have
14
banned the use of natural deer urine for lures, as the deer urine may be
sourced from CWD-endemic areas in the USA as well as from areas free of CWD. For
example, the US State of Virginia is banning the use of urine-based deer lures
on July 2015 and Vermont from 2016 due to the risk of spread of CWD. Alaska
banned their use in 2012 (Anon 2015a). Pennsylvania Game Commission has banned
urine-based deer lures and acknowledged that there is no way to detect their use
(Strausser 2014). On the basis of unpublished data (J. Manson, Pers. Comm.) it
appears that up to 50% of deer herds can be infected with 80-90% of animals
infected within some herds.
*** It is therefore assumed that probability that a 30-ml bottle of deer
urine lure imported from the USA is sources from an infected deer is medium.
SNIP...
In the USA, under the Food and Drug Administration’s BSE Feed Regulation
(21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin)
from deer and elk is prohibited for use in feed for ruminant animals. With
regards to feed for non-ruminant animals, under FDA law, CWD positive deer may
not be used for any animal feed or feed ingredients. ***For elk and deer
considered at high risk for CWD, the FDA recommends that these animals do not
enter the animal feed system. ***However, this recommendation is guidance and
not a requirement by law.
***Animals considered at high risk for CWD include:
***1) animals from areas declared to be endemic for CWD and/or to be CWD
eradication zones and
***2) deer and elk that at some time during the 60-month period prior to
slaughter were in a captive herd that contained a CWD-positive animal.
***Therefore, in the USA, materials from cervids other than CWD positive
animals may be used in animal feed and feed ingredients for non-ruminants. The
amount of animal PAP that is of deer and/or elk origin imported from the USA to
GB cannot be determined, however, as it is not specified in TRACES. It may
constitute a small percentage of the very low tonnage of non-fish origin
processed animal proteins that were imported from US into GB.
*** Overall, therefore, it is considered there is a greater than
negligible risk that (non-ruminant) animal feed and pet food containing deer
and/or elk protein is imported into GB. There is uncertainty associated with
this estimate given the lack of data on the amount of deer and/or elk protein
possibly being imported in these products.
SNIP...
Summary and MORE HERE ;
What is the risk of chronic wasting disease being introduced into Great
Britain? An updated Qualitative Risk Assessment March 2016
Tuesday, April 12, 2016
The first detection of Chronic Wasting Disease (CWD) in Europe
Saturday, January 31, 2015
European red deer (Cervus elaphus elaphus) are susceptible to Bovine
Spongiform Encephalopathy BSE by Oral Alimentary route
I strenuously once again urge the FDA and its industry constituents, to
make it MANDATORY that all ruminant feed be banned to all ruminants, and this
should include all cervids as soon as possible for the following reasons...
======
In the USA, under the Food and Drug Administrations BSE Feed Regulation
(21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin)
from deer and elk is prohibited for use in feed for ruminant animals. With
regards to feed for non-ruminant animals, under FDA law, CWD positive deer may
not be used for any animal feed or feed ingredients. For elk and deer considered
at high risk for CWD, the FDA recommends that these animals do not enter the
animal feed system.
***However, this recommendation is guidance and not a requirement by law.
======
31 Jan 2015 at 20:14 GMT
*** Ruminant feed ban for cervids in the United States? ***
31 Jan 2015 at 20:14 GMT
see Singeltary comment ;
Monday, March 28, 2016
National Scrapie Eradication Program February 2016 Monthly Report
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer
and Elk in Animal Feed Singeltary Submission
Greetings again FDA and Mr. Pritchett et al,
I would kindly like to comment on ;
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer
and Elk in Animal Feed Singeltary Submission
#158
Guidance for Industry
Use of Material from Deer and Elk in Animal Feed
This version of the guidance replaces the version made available
September15, 2003.
This document has been revised to update the docket number, contact
information, and standard disclosures. Submit comments on this guidance at any
time.
Submit electronic comments to http://www.regulations.gov. Submit written
comments to the Division of Dockets Management (HFA-305), Food and Drug
Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852. All comments
should be identified with the Docket No. FDA-2003-D-0432 (formerly 03D-0186).
For further information regarding this guidance, contact Burt Pritchett,
Center for Veterinary Medicine (HFV-222), Food and Drug Administration, 7519
Standish Place, Rockville, MD 20855, 240-402-6276, E-mail:
burt.pritchett@fda.hhs.gov.
Additional copies of this guidance document may be requested from the
Policy and Regulations Staff (HFV-6), Center for Veterinary Medicine, Food and
Drug Administration, 7519 Standish Place, Rockville, MD 20855, and may be viewed
on the Internet at either http://www.fda.gov/AnimalVeterinary/default.htm
or http://www.regulations.gov.
U.S. Department of Health and Human Services Food and Drug Administration
Center for Veterinary Medicine March 2016
Contains Nonbinding Recommendations
2
Guidance for Industry Use of Material from Deer and Elk in Animal Feed
This guidance represents the current thinking of the Food and Drug
Administration (FDA or Agency) on this topic. It does not establish any rights
for any person and is not binding on FDA or the public. You can use an
alternative approach if it satisfies the requirements of the applicable statutes
and regulations. To discuss an alternative approach, contact the FDA office
responsible for this guidance as listed on the title page.
I. Introduction
Under FDA’s BSE feed regulation (21 CFR 589.2000) most material from deer
and elk is prohibited for use in feed for ruminant animals. This guidance
document describes FDA’s recommendations regarding the use in all animal feed of
all material from deer and elk that are positive for Chronic Wasting Disease
(CWD) or are considered at high risk for CWD. The potential risks from CWD to
humans or non-cervid animals such as poultry and swine are not well understood.
However, because of recent recognition that CWD is spreading rapidly in
white-tailed deer, and because CWD’s route of transmission is poorly understood,
FDA is making recommendations regarding the use in animal feed of rendered
materials from deer and elk that are CWD-positive or that are at high risk for
CWD.
In general, FDA’s guidance documents do not establish legally enforceable
responsibilities. Instead, guidances describe the Agency’s current thinking on a
topic and should be viewed only as recommendations, unless specific regulatory
or statutory requirements are cited. The use of the word should in Agency
guidances means that something is suggested or recommended, but not required.
II. Background
CWD is a neurological (brain) disease of farmed and wild deer and elk that
belong in the animal family cervidae (cervids). Only deer and elk are known to
be susceptible to CWD by natural transmission. The disease has been found in
farmed and wild mule deer, white-tailed deer, North American elk, and in farmed
black-tailed deer. CWD belongs to a family of animal and human diseases called
transmissible spongiform encephalopathies (TSEs). These include bovine
spongiform encephalopathy (BSE or “mad cow” disease) in cattle; scrapie in sheep
and goats; and classical and variant Creutzfeldt-Jakob diseases (CJD and vCJD)
in humans. There is no known treatment for these diseases, and there is no
vaccine to prevent them. In addition, although validated postmortem diagnostic
tests are available, there are no validated diagnostic tests for CWD that can be
used to test for the disease in live animals.
Contains Nonbinding Recommendations
III. Use in animal feed of material from CWD-positive deer and elk
Material from CWD-positive animals may not be used in any animal feed or
feed ingredients. Pursuant to Sec. 402(a)(5) of the Federal Food, Drug, and
Cosmetic Act, animal feed and feed ingredients containing material from a
CWD-positive animal would be considered adulterated. FDA recommends that any
such adulterated feed or feed ingredients be recalled or otherwise removed from
the marketplace.
IV. Use in animal feed of material from deer and elk considered at high
risk for CWD Deer and elk considered at high risk for CWD include: (1) animals
from areas declared by State officials to be endemic for CWD and/or to be CWD
eradication zones; and (2) deer and elk that at some time during the 60-month
period immediately before the time of slaughter were in a captive herd that
contained a CWD-positive animal.
FDA recommends that materials from deer and elk considered at high risk
for CWD no longer be entered into the animal feed system. Under present
circumstances, FDA is not recommending that feed made from deer and elk from a
non-endemic area be recalled if a State later declares the area endemic for CWD
or a CWD eradication zone. In addition, at this time, FDA is not recommending
that feed made from deer and elk believed to be from a captive herd that
contained no CWD-positive animals be recalled if that herd is subsequently found
to contain a CWD-positive animal.
V. Use in animal feed of material from deer and elk NOT considered at high
risk for CWD FDA continues to consider materials from deer and elk NOT
considered at high risk for CWD to be acceptable for use in NON-RUMINANT animal
feeds in accordance with current agency regulations, 21 CFR 589.2000. Deer and
elk not considered at high risk include: (1) deer and elk from areas not
declared by State officials to be endemic for CWD and/or to be CWD eradication
zones; and (2) deer and elk that were not at some time during the 60-month
period immediately before the time of slaughter in a captive herd that contained
a CWD-positive animal.
3
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer
and Elk in Animal Feed Singeltary Submission
Greetings again FDA and Mr. Pritchett et al,
MY comments and source reference of sound science on this very important
issue are as follows ;
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer
and Elk in Animal Feed Singeltary Submission
I kindly wish to once again submit to Docket No. FDA-2003-D-0432 (formerly
03D-0186) Use of Material from Deer and Elk in Animal Feed.
Thank you kindly for allowing me to comment again, ...and again...and
again, on a topic so important, why it is ‘NON-BINDING’ is beyond me.
this should have been finalized and made ‘BINDING’ or MANDATORY OVER A
DECADE AGO.
but here lay the problem, once made ‘BINDING’ or ‘MANDATORY’, it is still
nothing but ink on paper.
we have had a mad cow feed ban in place since August 1997, and since then,
literally 100s of millions of pounds BANNED MAD COW FEED has been sent out to
commerce and fed out (see reference materials).
ENFORCEMENT OF SAID BINDING REGULATIONS HAS FAILED US TOO MANY TIMES.
so, in my opinion, any non-binding or voluntary regulations will not work,
and to state further, ‘BINDING’ or MANDATORY regulations will not work unless
enforced.
with that said, we know that Chronic Wasting Disease CWD TSE Prion easily
transmits to other cervid through the oral route.
the old transmission studies of BSE TSE floored scientist once they
figured out what they had, and please don’t forget about those mink that were
fed 95%+ dead stock downer cow, that all came down with TME. please see ;
It is clear that the designing scientists must also have shared Mr
Bradleys surprise at the results because all the dose levels right down to 1
gram triggered infection.
it is clear that the designing scientists must have also shared Mr
Bradleys surprise at the results because all the dose levels right down to 1
gram triggered infection.
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...
*** PLEASE SEE THIS URGENT UPDATE ON CWD AND FEED ANIMAL PROTEIN ***
Sunday, March 20, 2016
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer
and Elk in Animal Feed ***UPDATED MARCH 2016*** Singeltary Submission
*** Infectious agent of sheep scrapie may persist in the environment for
at least 16 years ***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
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 ;
with CWD TSE Prions, I am not sure there is any absolute yet, other than
what we know with transmission studies, and we know tse prion kill, and tse
prion are bad. science shows to date, that indeed soil, dirt, some better than
others, can act as a carrier. same with objects, farm furniture. take it with
how ever many grains of salt you wish, or not. if load factor plays a role in
the end formula, then everything should be on the table, in my opinion. see ;
***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 ;
Oral Transmissibility of Prion Disease Is Enhanced by Binding to Soil
Particles
Author Summary
Transmissible spongiform encephalopathies (TSEs) are a group of incurable
neurological diseases likely caused by a misfolded form of the prion protein.
TSEs include scrapie in sheep, bovine spongiform encephalopathy (‘‘mad cow’’
disease) in cattle, chronic wasting disease in deer and elk, and
Creutzfeldt-Jakob disease in humans. Scrapie and chronic wasting disease are
unique among TSEs because they can be transmitted between animals, and the
disease agents appear to persist in environments previously inhabited by
infected animals. Soil has been hypothesized to act as a reservoir of
infectivity and to bind the infectious agent. In the current study, we orally
dosed experimental animals with a common clay mineral, montmorillonite, or whole
soils laden with infectious prions, and compared the transmissibility to unbound
agent. We found that prions bound to montmorillonite and whole soils remained
orally infectious, and, in most cases, increased the oral transmission of
disease compared to the unbound agent. The results presented in this study
suggest that soil may contribute to environmental spread of TSEs by increasing
the transmissibility of small amounts of infectious agent in the environment.
tse prion soil
Wednesday, December 16, 2015
Objects in contact with classical scrapie sheep act as a reservoir for
scrapie transmission
The sources of dust borne prions are unknown but it seems reasonable to
assume that faecal, urine, skin, parturient material and saliva-derived prions
may contribute to this mobile environmental reservoir of infectivity. This work
highlights a possible transmission route for scrapie within the farm
environment, and this is likely to be paralleled in CWD which shows strong
similarities with scrapie in terms of prion dissemination and disease
transmission. The data indicate that the presence of scrapie prions in dust is
likely to make the control of these diseases a considerable challenge.
>>>Particle-associated PrPTSE molecules may migrate from
locations of deposition via transport processes affecting soil particles,
including entrainment in and movement with air and overland flow. <<<
Fate of Prions in Soil: A Review
Christen B. Smith, Clarissa J. Booth, and Joel A. Pedersen*
Several reports have shown that prions can persist in soil for several
years. Significant interest remains in developing methods that could be applied
to degrade PrPTSE in naturally contaminated soils. Preliminary research suggests
that serine proteases and the microbial consortia in stimulated soils and
compost may partially degrade PrPTSE. Transition metal oxides in soil (viz.
manganese oxide) may also mediate prion inactivation. Overall, the effect of
prion attachment to soil particles on its persistence in the environment is not
well understood, and additional study is needed to determine its implications on
the environmental transmission of scrapie and CWD.
P.161: Prion soil binding may explain efficient horizontal CWD
transmission
Conclusion. Silty clay loam exhibits highly efficient prion binding,
inferring a durable environmental reservoir, and an efficient mechanism for
indirect horizontal CWD transmission.
>>>Another alternative would be an absolute prohibition on the
movement of deer within the state for any purpose. While this alternative would
significantly reduce the potential spread of CWD, it would also have the
simultaneous effect of preventing landowners and land managers from implementing
popular management strategies involving the movement of deer, and would deprive
deer breeders of the ability to engage in the business of buying and selling
breeder deer. Therefore, this alternative was rejected because the department
determined that it placed an avoidable burden on the regulated
community.<<<
Wednesday, December 16, 2015
Objects in contact with classical scrapie sheep act as a reservoir for
scrapie transmission
Objects in contact with classical scrapie sheep act as a reservoir for
scrapie transmission
Timm Konold1*, Stephen A. C. Hawkins2, Lisa C. Thurston3, Ben C.
Maddison4, Kevin C. Gough5, Anthony Duarte1 and Hugh A. Simmons1
1 Animal Sciences Unit, Animal and Plant Health Agency Weybridge,
Addlestone, UK, 2 Pathology Department, Animal and Plant Health Agency
Weybridge, Addlestone, UK, 3 Surveillance and Laboratory Services, Animal and
Plant Health Agency Penrith, Penrith, UK, 4 ADAS UK, School of Veterinary
Medicine and Science, University of Nottingham, Sutton Bonington, UK, 5 School
of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington,
UK
Classical scrapie is an environmentally transmissible prion disease of
sheep and goats. Prions can persist and remain potentially infectious in the
environment for many years and thus pose a risk of infecting animals after
re-stocking. In vitro studies using serial protein misfolding cyclic
amplification (sPMCA) have suggested that objects on a scrapie affected sheep
farm could contribute to disease transmission. This in vivo study aimed to
determine the role of field furniture (water troughs, feeding troughs, fencing,
and other objects that sheep may rub against) used by a scrapie-infected sheep
flock as a vector for disease transmission to scrapie-free lambs with the prion
protein genotype VRQ/VRQ, which is associated with high susceptibility to
classical scrapie. When the field furniture was placed in clean accommodation,
sheep became infected when exposed to either a water trough (four out of five)
or to objects used for rubbing (four out of seven). This field furniture had
been used by the scrapie-infected flock 8 weeks earlier and had previously been
shown to harbor scrapie prions by sPMCA. Sheep also became infected (20 out of
23) through exposure to contaminated field furniture placed within pasture not
used by scrapie-infected sheep for 40 months, even though swabs from this
furniture tested negative by PMCA. This infection rate decreased (1 out of 12)
on the same paddock after replacement with clean field furniture. Twelve grazing
sheep exposed to field furniture not in contact with scrapie-infected sheep for
18 months remained scrapie free. The findings of this study highlight the role
of field furniture used by scrapie-infected sheep to act as a reservoir for
disease re-introduction although infectivity declines considerably if the field
furniture has not been in contact with scrapie-infected sheep for several
months. PMCA may not be as sensitive as VRQ/VRQ sheep to test for environmental
contamination.
snip...
Discussion
Classical scrapie is an environmentally transmissible disease because it
has been reported in naïve, supposedly previously unexposed sheep placed in
pastures formerly occupied by scrapie-infected sheep (4, 19, 20). Although the
vector for disease transmission is not known, soil is likely to be an important
reservoir for prions (2) where – based on studies in rodents – prions can adhere
to minerals as a biologically active form (21) and remain infectious for more
than 2 years (22). Similarly, chronic wasting disease (CWD) has re-occurred in
mule deer housed in paddocks used by infected deer 2 years earlier, which was
assumed to be through foraging and soil consumption (23).
Our study suggested that the risk of acquiring scrapie infection was
greater through exposure to contaminated wooden, plastic, and metal surfaces via
water or food troughs, fencing, and hurdles than through grazing. Drinking from
a water trough used by the scrapie flock was sufficient to cause infection in
sheep in a clean building. Exposure to fences and other objects used for rubbing
also led to infection, which supported the hypothesis that skin may be a vector
for disease transmission (9). The risk of these objects to cause infection was
further demonstrated when 87% of 23 sheep presented with PrPSc in lymphoid
tissue after grazing on one of the paddocks, which contained metal hurdles, a
metal lamb creep and a water trough in contact with the scrapie flock up to 8
weeks earlier, whereas no infection had been demonstrated previously in sheep
grazing on this paddock, when equipped with new fencing and field furniture.
When the contaminated furniture and fencing were removed, the infection rate
dropped significantly to 8% of 12 sheep, with soil of the paddock as the most
likely source of infection caused by shedding of prions from the
scrapie-infected sheep in this paddock up to a week earlier.
This study also indicated that the level of contamination of field
furniture sufficient to cause infection was dependent on two factors: stage of
incubation period and time of last use by scrapie-infected sheep. Drinking from
a water trough that had been used by scrapie sheep in the predominantly
pre-clinical phase did not appear to cause infection, whereas infection was
shown in sheep drinking from the water trough used by scrapie sheep in the later
stage of the disease. It is possible that contamination occurred through
shedding of prions in saliva, which may have contaminated the surface of the
water trough and subsequently the water when it was refilled. Contamination
appeared to be sufficient to cause infection only if the trough was in contact
with sheep that included clinical cases. Indeed, there is an increased risk of
bodily fluid infectivity with disease progression in scrapie (24) and CWD (25)
based on PrPSc detection by sPMCA. Although ultraviolet light and heat under
natural conditions do not inactivate prions (26), furniture in contact with the
scrapie flock, which was assumed to be sufficiently contaminated to cause
infection, did not act as vector for disease if not used for 18 months, which
suggest that the weathering process alone was sufficient to inactivate prions.
PrPSc detection by sPMCA is increasingly used as a surrogate for
infectivity measurements by bioassay in sheep or mice. In this reported study,
however, the levels of PrPSc present in the environment were below the limit of
detection of the sPMCA method, yet were still sufficient to cause infection of
in-contact animals. In the present study, the outdoor objects were removed from
the infected flock 8 weeks prior to sampling and were positive by sPMCA at very
low levels (2 out of 37 reactions). As this sPMCA assay also yielded 2 positive
reactions out of 139 in samples from the scrapie-free farm, the sPMCA assay
could not detect PrPSc on any of the objects above the background of the assay.
False positive reactions with sPMCA at a low frequency associated with de novo
formation of infectious prions have been reported (27, 28). This is in contrast
to our previous study where we demonstrated that outdoor objects that had been
in contact with the scrapie-infected flock up to 20 days prior to sampling
harbored PrPSc that was detectable by sPMCA analysis [4 out of 15 reactions
(12)] and was significantly more positive by the assay compared to analogous
samples from the scrapie-free farm. This discrepancy could be due to the use of
a different sPMCA substrate between the studies that may alter the efficiency of
amplification of the environmental PrPSc. In addition, the present study had a
longer timeframe between the objects being in contact with the infected flock
and sampling, which may affect the levels of extractable PrPSc. Alternatively,
there may be potentially patchy contamination of this furniture with PrPSc,
which may have been missed by swabbing. The failure of sPMCA to detect
CWD-associated PrP in saliva from clinically affected deer despite confirmation
of infectivity in saliva-inoculated transgenic mice was associated with as yet
unidentified inhibitors in saliva (29), and it is possible that the sensitivity
of sPMCA is affected by other substances in the tested material. In addition,
sampling of amplifiable PrPSc and subsequent detection by sPMCA may be more
difficult from furniture exposed to weather, which is supported by the
observation that PrPSc was detected by sPMCA more frequently in indoor than
outdoor furniture (12). A recent experimental study has demonstrated that
repeated cycles of drying and wetting of prion-contaminated soil, equivalent to
what is expected under natural weathering conditions, could reduce PMCA
amplification efficiency and extend the incubation period in hamsters inoculated
with soil samples (30). This seems to apply also to this study even though the
reduction in infectivity was more dramatic in the sPMCA assays than in the sheep
model. Sheep were not kept until clinical end-point, which would have enabled us
to compare incubation periods, but the lack of infection in sheep exposed to
furniture that had not been in contact with scrapie sheep for a longer time
period supports the hypothesis that prion degradation and subsequent loss of
infectivity occurs even under natural conditions.
In conclusion, the results in the current study indicate that removal of
furniture that had been in contact with scrapie-infected animals should be
recommended, particularly since cleaning and decontamination may not effectively
remove scrapie infectivity (31), even though infectivity declines considerably
if the pasture and the field furniture have not been in contact with
scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in
furniture that was subjected to weathering, even though exposure led to
infection in sheep, this method may not always be reliable in predicting the
risk of scrapie infection through environmental contamination. These results
suggest that the VRQ/VRQ sheep model may be more sensitive than sPMCA for the
detection of environmentally associated scrapie, and suggest that extremely low
levels of scrapie contamination are able to cause infection in susceptible sheep
genotypes.
Keywords: classical scrapie, prion, transmissible spongiform
encephalopathy, sheep, field furniture, reservoir, serial protein misfolding
cyclic amplification
Wednesday, December 16, 2015
*** Objects in contact with classical scrapie sheep act as a reservoir for
scrapie transmission ***
*** Infectious agent of sheep scrapie may persist in the environment for
at least 16 years ***
Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3
>>>Another alternative would be an absolute prohibition on the
movement of deer within the state for any purpose. While this alternative would
significantly reduce the potential spread of CWD, it would also have the
simultaneous effect of preventing landowners and land managers from implementing
popular management strategies involving the movement of deer, and would deprive
deer breeders of the ability to engage in the business of buying and selling
breeder deer. Therefore, this alternative was rejected because the department
determined that it placed an avoidable burden on the regulated
community.<<<
Circulation of prions within dust on a scrapie affected farm
Kevin C Gough1, Claire A Baker2, Hugh A Simmons3, Steve A Hawkins3 and Ben
C Maddison2*
Abstract
Prion diseases are fatal neurological disorders that affect humans and
animals. Scrapie of sheep/goats and Chronic Wasting Disease (CWD) of deer/elk
are contagious prion diseases where environmental reservoirs have a direct link
to the transmission of disease. Using protein misfolding cyclic amplification we
demonstrate that scrapie PrPSc can be detected within circulating dusts that are
present on a farm that is naturally contaminated with sheep scrapie. The
presence of infectious scrapie within airborne dusts may represent a possible
route of infection and illustrates the difficulties that may be associated with
the effective decontamination of such scrapie affected premises.
snip...
Discussion
We present biochemical data illustrating the airborne movement of scrapie
containing material within a contaminated farm environment. We were able to
detect scrapie PrPSc within extracts from dusts collected over a 70 day period,
in the absence of any sheep activity. We were also able to detect scrapie PrPSc
within dusts collected within pasture at 30 m but not at 60 m distance away from
the scrapie contaminated buildings, suggesting that the chance of contamination
of pasture by scrapie contaminated dusts decreases with distance from
contaminated farm buildings. PrPSc amplification by sPMCA has been shown to
correlate with infectivity and amplified products have been shown to be
infectious [14,15]. These experiments illustrate the potential for low dose
scrapie infectivity to be present within such samples. We estimate low ng levels
of scrapie positive brain equivalent were deposited per m2 over 70 days, in a
barn previously occupied by sheep affected with scrapie. This movement of dusts
and the accumulation of low levels of scrapie infectivity within this
environment may in part explain previous observations where despite stringent
pen decontamination regimens healthy lambs still became scrapie infected after
apparent exposure from their environment alone [16]. The presence of sPMCA
seeding activity and by inference, infectious prions within dusts, and their
potential for airborne dissemination is highly novel and may have implications
for the spread of scrapie within infected premises. The low level circulation
and accumulation of scrapie prion containing dust material within the farm
environment will likely impede the efficient decontamination of such scrapie
contaminated buildings unless all possible reservoirs of dust are removed.
Scrapie containing dusts could possibly infect animals during feeding and
drinking, and respiratory and conjunctival routes may also be involved. It has
been demonstrated that scrapie can be efficiently transmitted via the nasal
route in sheep [17], as is also the case for CWD in both murine models and in
white tailed deer [18-20].
The sources of dust borne prions are unknown but it seems reasonable to
assume that faecal, urine, skin, parturient material and saliva-derived prions
may contribute to this mobile environmental reservoir of infectivity. This work
highlights a possible transmission route for scrapie within the farm
environment, and this is likely to be paralleled in CWD which shows strong
similarities with scrapie in terms of prion dissemination and disease
transmission. The data indicate that the presence of scrapie prions in dust is
likely to make the control of these diseases a considerable challenge.
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
3:52 PM
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