Media Contact: Steve Lightfoot, TPWD, 512-389-4701,
steve.lightfoot@tpwd.texas.gov Callie McNulty, TAHC, 512-719-0728,
callie.mcnulty@tahc.texas.gov
July 1, 2015
Chronic Wasting Disease Detected in Medina County Captive Deer
AUSTIN – A two-year-old white-tailed deer in a Medina County deer breeding
facility has been confirmed positive for Chronic Wasting Disease (CWD). This is
the first case of CWD detected in captive white-tailed deer in Texas. CWD was
first detected in Texas in 2012 in free-ranging mule deer in the Hueco Mountains
in far West Texas.
The Medina County tissue samples submitted by the breeder facility in early
June as part of routine deer mortality surveillance revealed the presence of CWD
during testing at the Texas A&M Veterinary Medical Diagnostic Laboratory
(TVMDL) in College Station. The National Veterinary Services Laboratory in Ames,
Iowa, confirmed the findings on Tuesday, June 30.
An epidemiological investigation to determine the extent of the disease,
assess risks to Texas’ free ranging deer and protect the captive deer and elk
breeding industry is being led by the Texas Animal Health Commission (TAHC), in
coordination with the Texas Parks and Wildlife Department (TPWD) and U.S.
Department of Agriculture’s Animal and Plant Health Inspection Service
Veterinary Services (USDA/APHIS/VS).
Officials have taken immediate action to secure all cervids at the Medina
County breeder facility with plans to conduct additional investigation for CWD.
In addition, those breeder facilities that have received deer from the Medina
County facility or shipped deer to that facility during the last two years are
under movement restrictions and cannot move or release cervids at this time.
TPWD is disallowing liberation of captive deer from all breeder facilities into
the wild at this time pending further review. Additional measures to further
minimize risk of CWD spreading into Texas’ free-ranging white-tailed deer herd,
and to protect the captive deer breeding industry, will be considered.
“This is a terribly unfortunate development that we are committed to
addressing as proactively, comprehensively, and expeditiously as possible. The
health of our state’s wild and captive deer herds, as well as affiliated
hunting, wildlife, and rural based economies, are vitally important to Texas
hunters, communities, and landowners. As such, our primary objectives are to
determine the source of the disease and to identify other deer breeding
facilities and release sites that may have received deer from affected
facilities,” said Carter Smith, TPWD Executive Director. “Working
collaboratively with experts in the field we have developed protocols to address
CWD, and our implementation efforts are already well under way.”
The TPWD and the TAHC CWD Management Plan will guide the State’s response
to this incident. The plan was developed by the State’s CWD Task Force, which is
comprised of deer and elk breeders, wildlife biologists, veterinarians and other
animal-health experts from TPWD, TAHC, TVMDL, Department of State Health
Services, Texas A&M College of Veterinary Medicine, and USDA.
Since 2002, the state has conducted surveillance throughout Texas for the
disease. More than 34,000 samples collected from hunter-harvested and road kill
deer have been tested for CWD.
Although animal health and wildlife officials cannot say how long or to
what extent the disease has been present in the Medina County deer breeding
facility, the breeder has had an active CWD surveillance program since 2006 with
no positives detected until now.
“We are working with experts at the local, state and federal level, to
determine the extent of this disease, and respond appropriately to limit further
transmission,” said Dr. Andy Schwartz, TAHC Epidemiologist and Assistant
Executive Director. “Strong public awareness and the continued support of the
cervid industry is paramount to the success of controlling CWD in Texas.”
The disease was first recognized in 1967 in captive mule deer in Colorado.
CWD has also been documented in captive and/or free-ranging deer in 23 states
and 2 Canadian provinces. CWD among cervids is a progressive, fatal disease that
commonly results in altered behavior as a result of microscopic changes made to
the brain of affected animals. An animal may carry the disease for years without
outward indication, but in the latter stages, signs may include listlessness,
lowering of the head, weight loss, repetitive walking in set patterns, and a
lack of responsiveness. To date there is no evidence that CWD poses a risk to
humans or non-cervids. However, as a precaution, the U.S. Centers for Disease
Control and the World Health Organization recommend not to consume meat from
infected animals.
More information on CWD can be found on TPWD’s website,
www.tpwd.texas.gov/CWD or at the Chronic Wasting Disease Alliance website,
www.cwd-info.org.
More information about the TAHC CWD program may be found at http://tahc.state.tx.us/animal_health/cwd/cwd.html.
2015-07-01
*** 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
Chronic wasting disease (CWD) is a widespread and expanding prion disease
in free-ranging and captive cervid species in North America. The zoonotic
potential of CWD prions is a serious public health concern. Current literature
generated with in vitro methods and in vivo animal models (transgenic mice,
macaques and squirrel monkeys) reports conflicting results. The susceptibility
of human CNS and peripheral organs to CWD prions remains largely unresolved. In
our earlier bioassay experiments using several humanized transgenic mouse lines,
we detected protease-resistant PrPSc in the spleen of two out of 140 mice that
were intracerebrally inoculated with natural CWD isolates, but PrPSc was not
detected in the brain of the same mice. Secondary passages with such
PrPSc-positive CWD-inoculated humanized mouse spleen tissues led to efficient
prion transmission with clear clinical and pathological signs in both humanized
and cervidized transgenic mice. Furthermore, a recent bioassay with natural CWD
isolates in a new humanized transgenic mouse line led to clinical prion
infection in 2 out of 20 mice. ***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
The propensity for trans-species prion transmission is related to the
structural characteristics of the enciphering and heterologous PrP, but the
exact mechanism remains mostly mysterious. Studies of the effects of primary or
tertiary prion protein structures on trans-species prion transmission have
relied primarily upon animal bioassays, making the influence of prion protein
structure vs. host co-factors (e.g. cellular constituents, trafficking, and
innate immune interactions) difficult to dissect. As an alternative strategy, we
used real-time quakinginduced conversion (RT-QuIC) to investigate trans-species
prion conversion.
To assess trans-species conversion in the RT-QuIC system, we compared
chronic wasting disease (CWD) and bovine spongiform encephalopathy (BSE) prions,
as well as feline CWD (fCWD) and feline spongiform encephalopathy (FSE). Each
prion was seeded into each host recombinant PrP (full-length rPrP of
white-tailed deer, bovine or feline). We demonstrated that fCWD is a more
efficient seed for feline rPrP than for white-tailed deer rPrP, which suggests
adaptation to the new host.
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.***
================
cwd environmental load factor in the land and surrounding plants and
objects.
transportation of cervids and HUMANS from cwd zone should be regarded as a
great risk factor, and environmental contamination.
PL1
Using in vitro prion replication for high sensitive detection of prions and
prionlike proteins and for understanding mechanisms of transmission.
Claudio Soto
Mitchell Center for Alzheimer's diseases and related Brain disorders,
Department of Neurology, University of Texas Medical School at Houston.
Prion and prion-like proteins are misfolded protein aggregates with the
ability to selfpropagate to spread disease between cells, organs and in some
cases across individuals. I n T r a n s m i s s i b l e s p o n g i f o r m
encephalopathies (TSEs), prions are mostly composed by a misfolded form of the
prion protein (PrPSc), which propagates by transmitting its misfolding to the
normal prion protein (PrPC). The availability of a procedure to replicate prions
in the laboratory may be important to study the mechanism of prion and
prion-like spreading and to develop high sensitive detection of small quantities
of misfolded proteins in biological fluids, tissues and environmental samples.
Protein Misfolding Cyclic Amplification (PMCA) is a simple, fast and efficient
methodology to mimic prion replication in the test tube. PMCA is a platform
technology that may enable amplification of any prion-like misfolded protein
aggregating through a seeding/nucleation process. In TSEs, PMCA is able to
detect the equivalent of one single molecule of infectious PrPSc and propagate
prions that maintain high infectivity, strain properties and species
specificity. Using PMCA we have been able to detect PrPSc in blood and urine of
experimentally infected animals and humans affected by vCJD with high
sensitivity and specificity. Recently, we have expanded the principles of PMCA
to amplify amyloid-beta (Aβ) and alphasynuclein (α-syn) aggregates implicated in
Alzheimer's and Parkinson's diseases, respectively. Experiments are ongoing to
study the utility of this technology to detect Aβ and α-syn aggregates in
samples of CSF and blood from patients affected by these diseases.
***Recently, we have been using PMCA to study the role of environmental
prion contamination on the horizontal spreading of TSEs. These experiments have
focused on the study of the interaction of prions with plants and
environmentally relevant surfaces. Our results show that plants (both leaves and
roots) bind tightly to prions present in brain extracts and excreta (urine and
feces) and retain even small quantities of PrPSc for long periods of time.
Strikingly, ingestion of prioncontaminated leaves and roots produced disease
with a 100% attack rate and an incubation period not substantially longer than
feeding animals directly with scrapie brain homogenate. Furthermore, plants can
uptake prions from contaminated soil and transport them to different parts of
the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety
of environmentallyrelevant 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.
Wednesday, June 10, 2015
Zoonotic Potential of CWD Prions
LATE-BREAKING ABSTRACTS
O.05: Transmission of prions to primates after extended silent incubation
periods: Implications for BSE and scrapie risk assessment in human populations
Emmanuel Comoy, Jacqueline Mikol, Val erie Durand, Sophie Luccantoni,
Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys
Atomic Energy Commission; Fontenay-aux-Roses, France
Prion diseases (PD) are the unique neurodegenerative proteinopathies
reputed to be transmissible under field conditions since decades. The
transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that
an animal PD might be zoonotic under appropriate conditions. Contrarily, in the
absence of obvious (epidemiological or experimental) elements supporting a
transmission or genetic predispositions, PD, like the other proteinopathies, are
reputed to occur spontaneously (atpical animal prion strains, sporadic CJD
summing 80% of human prion cases). Non-human primate models provided the first
evidences supporting the transmissibiity of human prion strains and the zoonotic
potential of BSE. Among them, cynomolgus macaques brought major information for
BSE risk assessment for human health (Chen, 2014), according to their
phylogenetic proximity to humans and extended lifetime. We used this model to
assess the zoonotic potential of other animal PD from bovine, ovine and cervid
origins even after very long silent incubation periods. *** We recently observed
the direct transmission of a natural classical scrapie isolate to macaque after
a 10-year silent incubation period, ***with features similar to some reported
for human cases of sporadic CJD, albeit requiring fourfold longe incubation than
BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014), ***is the
third potentially zoonotic PD (with BSE and L-type BSE), ***thus questioning the
origin of human sporadic cases. We will present an updated panorama of our
different transmission studies and discuss the implications of such extended
incubation periods on risk assessment of animal PD for human health.
===============
***thus questioning the origin of human sporadic cases...TSS
===============
Friday, January 30, 2015
*** Scrapie: a particularly persistent pathogen ***
Tuesday, December 16, 2014 Scrapie from sheep could infect humans with 'mad
cow disease', study finds
Evidence for zoonotic potential of ovine scrapie prions
Hervé Cassard,1, n1 Juan-Maria Torres,2, n1 Caroline Lacroux,1, Jean-Yves
Douet,1, Sylvie L. Benestad,3, Frédéric Lantier,4, Séverine Lugan,1, Isabelle
Lantier,4, Pierrette Costes,1, Naima Aron,1, Fabienne Reine,5, Laetitia
Herzog,5, Juan-Carlos Espinosa,2, Vincent Beringue5, & Olivier Andréoletti1,
Affiliations Contributions Corresponding author Journal name: Nature
Communications Volume: 5, Article number: 5821 DOI: doi:10.1038/ncomms6821
Received 07 August 2014 Accepted 10 November 2014 Published 16 December 2014
Article tools Citation Reprints Rights & permissions Article metrics
Abstract
Although Bovine Spongiform Encephalopathy (BSE) is the cause of variant
Creutzfeldt Jakob disease (vCJD) in humans, the zoonotic potential of scrapie
prions remains unknown. Mice genetically engineered to overexpress the human
prion protein (tgHu) have emerged as highly relevant models for gauging the
capacity of prions to transmit to humans. These models can propagate human
prions without any apparent transmission barrier and have been used used to
confirm the zoonotic ability of BSE. Here we show that a panel of sheep scrapie
prions transmit to several tgHu mice models with an efficiency comparable to
that of cattle BSE. ***The serial transmission of different scrapie isolates in
these mice led to the propagation of prions that are phenotypically identical to
those causing sporadic CJD (sCJD) in humans. ***These results demonstrate that
scrapie prions have a zoonotic potential and raise new questions about the
possible link between animal and human prions.
Subject terms: Biological sciences• Medical research At a glance
see more here ;
Wednesday, March 18, 2015
Chronic Wasting Disease CWD Confirmed Texas Trans Pecos March 18,
2015
Wednesday, March 25, 2015
Chronic Wasting Disease CWD Cases Confirmed In New Mexico 2013 and 2014
UPDATE 2015
Friday, May 22, 2015
Chronic Wasting Disease and Program Updates - 2014 NEUSAHA Annual Meeting
12-14 May 2014
Thank You For Your Comments
Thank you for submitting your comments on the Draft Deer Management Plan.
https://www3.dgif.virginia.gov/web/wildlife/deer/management-plan/draft/comment/thanks/
Wednesday, July 01, 2015
DRAFT Virginia Deer Management Plan 2015-2024 (bans urine scents do to CWD
2015)
Terry S. Singeltary Sr.
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