Review and Updates of the USDA-APHIS Veterinary Services (VS) National Chronice Wasting Disease (CWD) Program 2012-2013
Review and Updates of the USDA-APHIS Veterinary Services (VS) National
Chronice Wasting Disease (CWD) Program
Dr. Patrice Klein
USDA-APHIS-VS
CWD Rule Update
CWD Interim Final Rule was published on June 8, 2012, establishing a
national voluntary CWD herd certification program (HCP) and consistent minimum
interstate movement requirements. The rule became effective on August 13, 2012.
Enforcement of the interstate movement regulations is delayed until December 10,
2012 to give States time to apply to APHIS to become an Approved State CWD
HCP.
After reviewing the public comments, the APHIS will issue a final rule, and
if needed, incorporate any changes made in response to comments on preemption.
Comments received on other topics will be held for future rulemaking. The goal
of the CWD Program is to assist States, Tribes, and the cervid industry to
prevent and control spread of CWD in farmed and wild cervid populations through
establishment of a national CWD HCP and interstate movement requirements.
APHIS provides federal oversight of the voluntary national CWD HCP with
program activities conducted by the Approved State CWD HCPs. APHIS will serve in
an advisory capacity to Approved States for epidemiological investigations on
CWD positive findings, development of herd plans, and assist (where possible)
with herd inspections and inventories.
APHIS will continue to fund confirmatory testing on any presumptive
CWD-positive samples from farmed and wild cervids, conducted by the National
Veterinary Services Laboratories (NVSL).
Farmed/captive cervid surveillance testing
Through FY2012, CWD surveillance testing was conducted on approximately
22,585 farmed /captive cervids by the immunohistochemistry (IHC) standard
protocol. This reflects testing that was funded by APHIS through December 2011
and the transition to these laboratory costs paid directly by the cervid owner
beginning in January 2012 as a result of CWD program budget reductions in
FY2012.
Farmed/captive cervid CWD status
To date, 60 farmed/captive cervid herds have been identified in 13 states:
Colorado, Iowa, Kansas, Michigan, Minnesota, Missouri, Montana, Nebraska, New
York, Oklahoma, Pennsylvania, South Dakota and Wisconsin. Forty were elk herds,
19 were whitetail deer (WTD) herds, and one was the red deer herd. At this time,
15 CWD positive herds remain – seven elk herds in Colorado, three elk herds in
Nebraska, three WTD herds in Iowa, one WTD herd in Pennsylvania, and one red
deer herd in Minnesota.
On October 11, 2012, Pennsylvania reported a CWD positive three and
one-half year old female white-tailed deer (WTD) in a farmed cervid herd in
Adams County, Pennsylvania. NVSL conducted the confirmatory CWD testing and this
represents the first report of CWD in PA. The index herd is under state
quarantine, and an epidemiological investigation and trace outs are in progress
to identify epidemiologically-linked premises in Pennsylvania and other
states.
In July, 2012, Iowa reported a CWD positive six year old male WTD in a hunt
facility in Davis County, Iowa that was sourced from a deer breeding farm under
the same ownership in Cerro Gordo County, Iowa. Trace outs identified several
other premises that purchased deer from the index herd. CWD testing of the
traced out animals has begun. To date, one CWD positive doe was identified in
the source herd that had direct contact with the index animal, and four
additional CWD positive deer (including two purchased deer) have been identified
on separately owned premises.
In May 2012, Minnesota reported CWD in a two and one-half year old male red
deer from a breeding farm in Ramsey County, Minnesota. This represents the first
report of CWD in red deer (Cervus elaphus) in the United States. During the
epidemiological investigation, 56 pen mates (cohorts) were tested and CWD was
not detected in any of those animals. No point source of introduction yet has
been determined. The herd remains under state imposed quarantine which is
allowing for some animals to be transported directly to a slaughter facility.
All slaughtered animals have been CWD tested and reported as ‘not
detected’.
Wild Cervid surveillance
In FY2011, cooperative agreements were awarded to 46 State wildlife
agencies (approximately $4.2 M) and 34 Native American Tribes (approximately
$340,000). The Native American Fish and Wildlife Society received approximately
$175,000 to support CWD outreach and education activities Cooperative agreement
funds were eliminated in FY2012 due to federal budget reductions.
FY2010 funding supported surveillance in approximately 74,900 wild cervids
in 46 cooperating States. Wild cervid CWD surveillance totals are pending for
FY2011 due to seasonal surveillance activities and completion of final
cooperative agreement reporting to APHIS. To date, approximately 60,890 wild
cervids have been tested in fiscal year 2011.
Budget: Commodity Health Line Structure
In FY2011, APHIS received approximately $15.8 million in appropriated
funding for the CWD Program. In the FY2012 budget, livestock commodities
regulated by USDA were organized into ‘Commodity Health Line’ structures or
groupings. APHIS’ Equine, Cervid and Small Ruminant (ECSR) Health line supports
efforts to protect the health and thereby improve the quality and productivity
of the equine, cervid and small ruminant industries. In FY2012 approximately
$1.925 million of ECSR funding was allocated for CWD program activities to
provide Federal oversight of the national CWD herd certification program (HCP).
The President’s FY2013 budget proposes further funding reductions.
UNITED STATES ANIMAL HEALTH ASSOCIATION
2012 Resolution
___________________________________________________________________________
RESOLUTION NUMBER: 20 APPROVED
SOURCE: COMMITTEE ON CAPTIVE WILDLIFE AND ALTERNATIVE LIVESTOCK
SUBJECT MATTER: CHRONIC WASTING DISEASE CONTROL
BACKGROUND INFORMATION:
It has been stated by the United States Department of Agriculture, Animal
and Plant Health Inspection Service, Veterinary Services that (1) the goal of
the Chronic Wasting Disease (CWD) program in the United States has now changed
from eradication to controlling its spread, (2) there is no longer federal
funding available to pay for CWD testing or to pay indemnity for CWD infected or
exposed animals, and (3) depopulation of infected herds will no longer be
required or expected.
With this major change in objectives, it is critical that we change the way
we implement the CWD program in the United States. We now need a program that
minimizes the risk of spreading CWD in farmed and wild cervidae without putting
farmed cervidae producers out of business if their herds become CWD infected or
exposed. We need a CWD control program that includes plans for how to (1) handle
infected or exposed herds, (2) clean up infected herds without depopulation, and
(3) provide outlets so producers can continue to sell velvet antler and live
animals to slaughter or specified terminal facilities.
RESOLUTION:
The United States Animal Health Association urges the United States
Department of Agriculture, Animal and Plant Health Inspection Service,
Veterinary Services and state animal health regulatory officials to develop
protocols for the Chronic Wasting Disease (CWD) control program that mitigate
the risk of the spread of CWD and allow producers with CWD infected or exposed
herds to continue operations under quarantine and which allow (1) addition of
cervidae from CWD certified herds, (2) participation in herd plans such as test
and removal, and (3) movement of velvet antler and live animals to slaughter or
other approved terminal facilities.
UNITED STATES ANIMAL HEALTH ASSOCIATION
2012 Resolution
___________________________________________________________________________
INTERIM RESPONSE:
The U.S. Department of Agriculture, Animal and Plant Health Inspection
Service, Veterinary Services (VS) recognizes the concerns of the United States
Animal Health Association and appreciates the opportunity to respond. In
conjunction with the publication of the chronic wasting disease (CWD) final rule
in June 2012, VS prepared a set of program standards governing the voluntary
national herd certification program. The standards provide further explanation
and guidance on how participating States and cervid owners can meet the program
requirements to certify herds as low risk for CWD.
The standards are divided into two parts. Part A covers herd certification
program participation requirements; registration, identification, and
recordkeeping; surveillance and sampling; and diagnostics and testing. It also
describes the requirements for interstate movement of cervids in accordance with
the rule. Part B provides guidance to States for responding to findings of CWD
in farmed cervids, in accordance with the national CWD herd certification
program. This section also provides suggested best management practices that may
be used by States and by herd owners to investigate and manage CWD-affected
herds, including development of herd plans and factors affecting continuity of
business. VS will continue to serve in an advisory capacity to assist States and
herd owners with these mitigation efforts. VS has convened a working group to
review the program standards (see Resolution 24).
UNITED STATES ANIMAL HEALTH ASSOCIATION
2012 Resolution
___________________________________________________________________________
RESOLUTION NUMBER: 24 APPROVED
SOURCE: COMMITTEE ON CAPTIVE WILDLIFE AND ALTERNATIVE LIVESTOCK
SUBJECT MATTER: CHRONIC WASTING DISEASE PROGRAM STANDARDS
BACKGROUND INFORMATION:
It has been stated by the United States Department of Agriculture (USDA),
Animal and Plant Health Inspection Service (APHIS), Veterinary Services (VS)
that the goal of the Chronic Wasting Disease (CWD) program in the United States
has now changed from eradication to controlling its spread.
The document entitled, "Chronic Wasting Disease Program Standards" was
published by USDA-APHIS-VS in July 2012. It was developed before the shift of
the CWD program from eradication to control and without adequate input from
state wildlife and animal health officials or farmed cervidae producers.
Sections of the document suggest placing restrictions on farmed cervidae
producers that do nothing to further the effort to control the spread of CWD.
The restrictions are not based on current scientific knowledge and could
undermine the success of CWD control programs that have been in place in many
states for more than a decade.
RESOLUTION:
The United States Animal Health Association urges the United States
Department of Agriculture (USDA), Animal and Plant Health Inspection Service
(APHIS), Veterinary Services (VS) to revise the document entitled, "Chronic
Wasting Disease Program Standards", and establish a Chronic Wasting Disease
(CWD) Program Standards Committee to review and rewrite the document within 90
days so that it more appropriately reflects the needs of producers and
regulatory officials charged with implementation of a program to control, not
eradicate, CWD in the United States.
The United States Animal Health Association suggests that the CWD Program
Standards Committee should be made up of representatives from and appointed by
each of the following organizations: (1) the Exotic Wildlife Association, (2)
the North American Elk Breeders Association, (3) the North American Deer Farmers
Association, (4) the Association of Fish and Wildlife Agencies, (5) the National
Assembly of State Animal Health Officials, and (6) the USDA-APHIS-VS.
UNITED STATES ANIMAL HEALTH ASSOCIATION
2012 Resolution
___________________________________________________________________________
INTERIM RESPONSE:
The U.S. Department of Agriculture, Animal and Plant Health Inspection
Service, Veterinary Services (VS) recognizes the concerns of the United States
Animal Health Association (USAHA) and appreciates the opportunity to respond. To
address a number of concerns voiced at the 2012 USAHA meeting, VS established a
CWD Program Standards Working Group. The goal of the working group is to discuss
stakeholder concerns with the CWD program standards and to recommend revisions
as necessary. The group is composed of three representatives each from the
National Assembly, the Association of Fish and Wildlife Agencies, and the cervid
industry; two representatives from the American Association of Veterinary
Laboratory Diagnosticians; and experts from VS.
The working group first met on November 28, 2012, and continues to have
weekly teleconferences. We expect revisions to the program standards to be
completed by the first week of March. The revised program standards will then be
made available for public comment through a notice in the Federal Register.
2012 Resolution 13: FUNDING FOR INDEMNITY OF CHRONIC WASTING DISEASE
POSITIVE OR EXPOSED ANIMALS
Resolution 15: VACCINE FOR THE VARIOUS STRAINS OF EPIZOOTIC HEMORRHAGIC
DISEASE IN CERVIDS
Resolution 20: CHRONIC WASTING DISEASE CONTROL
Resolution 21: FUNDING FOR CHRONIC WASTING DISEASE TESTING
Resolution 24: CHRONIC WASTING DISEASE PROGRAM STANDARDS
Wednesday, September 04, 2013
cwd - cervid captive livestock escapes, loose and on the run in the wild...
Thursday, August 08, 2013
***PRION2013 CONGRESSIONAL ABSTRACTS
Characterization of the first case of naturally occurring chronic wasting
disease in a captive red deer (Cervus elaphus) in North America
Sunday, August 25, 2013
***PRION2013 CONGRESSIONAL ABSTRACTS
Prion2013 Chronic Wasting Disease CWD risk factors, humans, domestic cats,
blood, and mother to offspring transmission
***PRION2013 CONGRESSIONAL ABSTRACTS
HD.13: CWD infection in the spleen of humanized transgenic mice
Liuting Qing and Qingzhong Kong
Case Western Reserve University; Cleveland, OH USA
Chronic wasting disease (CWD) is a widespread prion disease in free-ranging
and captive cervid species in North America, and there is evidence suggesting
the existence of multiple CWD strains. The susceptibility of human CNS and
peripheral organs to the various CWD prion strains remains largely unclear.
Current literature suggests that the classical CWD strain is unlikely to infect
human brain, but the potential for peripheral infection by CWD in humans is
unknown. We detected protease-resistant PrpSc in the spleens of a few humanized
transgenic mice that were intracerebrally inoculated with natural CWD isolates,
but PrpSc was not detected in the brains of any of the CWD-inoculated mice. Our
ongoing bioassays in humanized Tg mice indicate that intracerebral challenge
with such PrpSc-positive humanized mouse spleen already led to prion disease in
most animals. These results indicate that the CWD prion may have the potential
to infect human peripheral lymphoid tissues.
=====
HD.12: Comparative study of the distribution of the prion protein in the
squirrel monkey (Saimiri sciureus) following experimental challenge with variant
and sporadic CJD
Diane L. Ritchie,1 Paul Brown,2 Susan Gibson,3 Thomas R. Kreil,4 Christian
Abee3 and James W. Ironside1
1National CJD Surveillance Unit; Edinburgh, UK; 2Bethesda; Bethesda, MD
USA; 3Deparment of Comparative Medicine; University of South Alabama; Mobile, AL
USA; 4Baxter Bioscience; Vienna, Austria
Introduction, Reports suggest that the number of tissues and organs showing
the presence of the abnormal prion protein (PrPTSE) in variant CJD (vCJD)
patients may be greater than previously thought. A limited peripheral
involvement in some cases of sporadic CJD (sCJD) has also been reported. This
accumulation of PrPTSE outside the brain has raised concerns about the possible
iatrogenic transmission risk of vCJD. The squirrel monkey (Saimiri sciureus) has
been shown to be highly susceptible to experimental challenge with human prion
disease. Neuropathological and biochemical analyses of CNS tissue have shown
that sCJD and vCJD can be distinguished in the squirrel monkey and that many of
the strain characteristics that define these agents are conserved after
transmission. Following on from these initial studies, immunohistochemistry and
western blot analysis were performed on a wide range of peripheral tissues
including, lymphoreticular tissues and peripheral neural tissue to establish the
full-body distribution of PrPTSE in this primate animal model.
Materials and Methods. Brain homogenates from sCJD or vCJD patients were
inoculated into the frontal cortex of squirrel monkeys. Animals were kept under
constant clinical surveillance. At post-mortem, formalin fixed CNS tissue and a
wide range of peripheral tissues were taken for immunohistochemical analysis
together with frozen tissues taken for the biochemical detection of PrPTSE.
Results. Immunohistochemical analysis showed no evidence of PrPTSE
deposition in peripheral tissues in either variant or sporadic CJD-infected
animals. However, western blot assays detected PrPTSE in the spleen of a
proportion of the vCJD- infected animals. The PrPTSE isotype resembled that
detected in CNS tissue from the vCJD- infected animals and from human vCJD
cases. ***In addition, western blot analysis detected PrPTSE in the spleen of a
single animal following challenge with sporadic CJD. The PrPTSE type in this
animal resembled that found in CNS tissue from the same animal, with a PrPTSE
type similar to that found in human sCJD type 1 cases.
Conclusion. This study confirms the accumulation of PrPTSE in the CNS and
spleen of a proportion of squirrel monkeys infected intra-cerebrally with human
vCJD. Furthermore, this study extends the evidence that there may be a
peripheral involvement in some cases of sCJD. PrPTSE typing confirms the
conservation of PrPTSE type on transmission to the squirrel monkey and suggests
that there are no tissue-specific adaptations in the biochemical phenotype of
the agent strain following primate-to-primate transmission.
=====
Oral.15: Molecular barriers to zoonotic prion transmission: Comparison of
the ability of sheep, cattle and deer prion disease isolates to convert normal
human prion protein to its pathological isoform in a cell-free system
Marcelo A.Barria,1 Aru Balachandran,2 Masanori Morita,3 Tetsuyuki
Kitamoto,4 Rona Barron,5 Jean Manson,5 Richard Kniqht,1 James W. lronside1 and
Mark W. Head1
1National CJD Research and Surveillance Unit; Centre for Clinical Brain
Sciences; School of Clinical Sciences; The University of Edinburgh; Edinburgh,
UK; 2National and OIE Reference Laboratory for Scrapie and CWD; Canadian Food
Inspection Agency; Ottawa Laboratory; Fallowfield. ON Canada; 3Infectious
Pathogen Research Section; Central Research Laboratory; Japan Blood Products
Organization; Kobe, Japan; 4Department of Neurological Science; Tohoku
University Graduate School of Medicine; Sendai. Japan; 5Neurobiology Division;
The Roslin Institute and R(D)SVS; University of Edinburgh; Easter Bush;
Midlothian; Edinburgh, UK
Background. Bovine spongiform encephalopathy (BSE) is a known zoonotic
prion disease, resulting in variant Creurzfeldt- Jakob disease (vCJD) in humans.
In contrast, classical scrapie in sheep is thought to offer little or no danger
to human health. However, a widening range of prion diseases have been
recognized in cattle, sheep and deer. The risks posed by individual animal prion
diseases to human health cannot be determined a priori and are difficult to
assess empirically. The fundamemal event in prion disease pathogenesis is
thought to be the seeded conversion of normal prion protein (PrPC) to its
pathological isoform (PrPSc). Here we report the use of a rapid molecular
conversion assay to test whether brain specimens from different animal prion
diseases are capable of seeding the conversion of human PrPC ro PrPSc.
Material and Methods. Classical BSE (C-type BSE), H-type BSE, L-type BSE,
classical scrapie, atypical scrapie, chronic wasting disease and vCJD brain
homogenates were tested for their ability to seed conversion of human PrPC to
PrPSc in protein misfolding cyclic amplification (PMCA) reactions. Newly formed
human PrPSc was detected by protease digestion and western blotting using the
antibody 3F4.
Results. C-type BSE and vCJD were found to efficiently convert PrPC to
PrPSc. Scrapie failed to convert human PrPC to PrPSc. Of the other animal prion
diseases tested only chronic wasting disease appeared to have the capability ro
convert human PrPC to PrPSc. The results were consistent whether the human PrPC
came from human brain, humanised transgenic mouse brain or from cultured human
cells and the effect was more pronounced for PrPC with methionine at codon 129
compared with that with valine.
Conclusion. Our results show that none of the tested animal prion disease
isolates are as efficient as C-type BSE and vCJD in converting human prion
protein in this in vitro assay. However, they also show that there is no
absolute barrier ro conversion of human prion protein in the case of chronic
wasting disease.
=====
Invited.16: Studies of chronic wasting disease transmission in cervid and
non-cervid species
Edward A, Hoover,1 Candace K. Mathiason,1 Davin M. Henderson,1 Nicholas J.
Haley,1 Davis M. Seelig,1 Nathaniel D. Denkers,1 Amy V. Nalls,1 Mark D. Zabe,1
Glenn C. Telling,1 Fernando Goni2 and Thomas Wisniewski,2
1Prion Research Center; Colorado State University; Fort Collins, CO USA;
2New York University School of Medicine; New York, NY USA
How and why some misfolded proteins become horizontally transmitted agents
and occasionally cross species barriers are issues fundamental to understanding
prion disease. Chronic wasting disease (CWD) of cervids is perhaps a prototype
of horizontal prion transmission, encompassing efficient mucosal uptake,
lymphoid amplification, neuroinvasion, peripheralization, and dissemination via
mucosal excretion. Efficient mucosal transmission of CWD in deer has been
demonstrated by oral, nasal, aerosol, and indirect contact exposure. In
addition, other studies (Mathiason CK, et al.) reported at the symposium support
a significant role for pre- and/or postnatal transmission of CWD from doe to
offspring. Accumulating, yet still incomplete, evidence also suggests that the
period of relatively covert CWD infection may be longer than originally thought.
Given the above, minimally invasive sensitive assays based on body fluids from
live animals would aid substantially in understanding the biology of CWD. We
have been applying seeded realtirne quaking-induced amplification of recombinant
PrP substrates (i.e., RT-QuIC methodology) to: (1) investigate antemortem CWD
detection, and (2) model PrP-based species barriers and trans-species
adaptation-topics we previously explored using sPMCA and in vivo bioassays. At
this symposium, we report sensitive and specific detection CWD prions in saliva,
urine, blood (Mathiason lab), and rectal and pharyngeal lymph node samples
(Haley NJ, et al.) from pre-symptomatic and symptomatic experimentally and
naturally exposed deer. Other ongoing studies are employing RT-QuIC methodology
to model amplification barriers among CWD, FSE, BSE, and CJD prions using
cervine, feline, bovine, human, and promiscuous rPrP substrates and the above
species prion seeds, cellular co-factors, and transgenic mice. Finally, in
collaboration with the Wisniewski laboratory, we are conducting of experimental
CWD vaccination studies in deer employing oral administration of an attenuated
Salmonella vector expressing cervid PrP epitopes.
=====
AD.06: Detecting prions in the brain and blood of TSE-infected deer and
hamsters
Alan Elder,1 Davin Henderson,1 Anca Selariu,1 Amy Nalls,1 Byron Caughey,2
Richard Bessen,1 Jason Bartz3 and Candace Mathiason1
1Colorado State University; Fort Collins, CO USA; 2NIH Rocky Mountain
Laboratories; Hamilton, MT USA; 3Creighton University; Omaha, NE USA
While large quantities of protease resistant prion protein (PrPres) can be
demonstrated by western blot or IHC in lymphoid biopsies or post-mortem brain
tissues harvested from prion-infected animals, these conventional assays are
less reliable as means to detect the small quantities of prions thought to be
present in bodily fluids or associated with early and asymptomatic phases of TSE
disease. The Real Time-Quaking Induced Conversion (RT-QuIC) assay is capable of
detecting prions at concentrations below the level of sensitivity of
conventional assays and provides a real-time fluorescent readout negating the
use of proteases. We have made modifications to the RT-QuIC assay to utilize it
for the detection of PrPres in brain and blood harvested from various species
infected with prions. In this study, we analyzed CWD-infected deer and
CWD/TME-infected hamster whole blood to determine the effect of:
(1) various anticoagulants,
(2) freezing and
(3) NaPTA precipitation.
Brain tissue and blood collected from naive deer and hamsters served as
negative controls.
We were able to demonstrate amplifiable prions in
(1) brain and blood samples harvested from CWD/TME-infected animals,
(2) heparinized blood,
(3) frozen vs. fresh blood and
(4) NaPTA treated samples.
The RT-QuIC assay is able to detect PrPres in various species of animals
and shows promise as an antemortem diagnostic tool for blood-borne TSEs.
=====
Oral.08: Mother to offspring transmission of chronic wasting disease in
Reeve's Muntjac deer
Amy Nalls,1 Erin McNulty,1 Jenny Powers,2 Davis Seelig,1 Clare Hoover,1
Nicholas Haley,1 Jeanette Hayes-Klug,1 Kelly Anderson,1 Paula Stewart,3 Wilfred
Goldmann,3 Edward A. Hoover1 and Candace K. Mathiason1
1Colorado State University; Fort Collins, CO USA; 2National Park Service;
Fort Collins, CO USA; 3The Roslin Institute and Royal School of Veterinary
Studies; Edinburgh, UK
To investigate the role mother to offspring transmission plays in chronic
wasting disease (CWD), we have developed a cervid model employing the Reeve's
muntjac deer (Muntiacus reevesi). Eight muntjac doe were orally inoculated with
CWD and tested PrPCWD lymphoid positive by 4 mo post infection. Fourteen fawns
were born to these eight CWD-infected doe-3 were born viable, 6 were born
non-viable and 5 were harvested as fetuses from early or end-stage CWD-infected
doe. All three viable fawns have demonstrated CWD IHC lymphoid biopsy positivity
between 43 d post birth and 11 mo post birth. Two of these three CWD positive
viable offspring have developed clinical signs consistent with TSE disease
(28-33 mo post birth). Moreover, CWD prions have been detected by sPMCA in 11 of
16 tissues harvested from 6 full-term non-viable fawns and in 7 of 11 fetal
tissues harvested in utero from the second and third trimester fetuses.
Additional tissues and pregnancy related fluids from doe and offspring are being
analyzed for CWD prions. In summary, using the muntjac deer model we have
demonstrated CWD clinical disease in offspring born to CWD-infected doe, and in
utero transmission of CWD from mother to offspring. These studies provide basis
to further investigate the mechanisms of maternal transfer of prions.
=====
AD.63: Susceptibility of domestic cats to chronic wasting disease
Amy V.Nalls,1 Candace Mathiason,1 Davis Seelig,2 Susan Kraft,1 Kevin
Carnes,1 Kelly Anderson,1 Jeanette Hayes-Klug1 and Edward A. Hoover1
1Colorado State University; Fort Collins, CO USA; 2University of Minnesota;
Saint Paul, MN USA
Domestic and nondomestic cats have been shown to be susceptible to feline
spongiform encephalopathy (FSE), almost certainly caused by consumption of
bovine spongiform encephalopathy (BSE)-contaminated meat. Because domestic and
free-ranging nondomestic felids scavenge cervid carcasses, including those in
areas affected by chronic wasting disease (CWD), we evaluated the susceptibility
of the domestic cat (Felis catus) to CWD infection experimentally. Cohorts of 5
cats each were inoculated either intracerebrally (IC) or orally (PO) with
CWD-infected deer brain. At 40 and 42 mo post-inoculation, two IC-inoculated
cats developed signs consistent with prion disease, including a stilted gait,
weight loss, anorexia, polydipsia, patterned motor behaviors, head and tail
tremors, and ataxia, and progressed to terminal disease within 5 mo. Brains from
these two cats were pooled and inoculated into cohorts of cats by IC, PO, and
intraperitoneal and subcutaneous (IP/SC) routes. Upon subpassage, feline-adapted
CWD (FelCWD) was transmitted to all IC-inoculated cats with a decreased
incubation period of 23 to 27 mo. FelCWD was detected in the brains of all the
symptomatic cats by western blotting and immunohistochemistry and abnormalities
were seen in magnetic resonance imaging, including multifocal T2 fluid
attenuated inversion recovery (FLAIR) signal hyper-intensities, ventricular size
increases, prominent sulci, and white matter tract cavitation. Currently, 3 of 4
IP/SQ and 2 of 4 PO inoculared cats have developed abnormal behavior patterns
consistent with the early stage of feline CWD. These results demonstrate that
CWD can be transmitted and adapted to the domestic cat, thus raising the issue
of potential cervid-to- feline transmission in nature.
snip...see full text ;
Sunday, August 25, 2013
***PRION2013 CONGRESSIONAL ABSTRACTS
Prion2013 Chronic Wasting Disease CWD risk factors, humans, domestic cats,
blood, and mother to offspring transmission
Sunday, July 21, 2013
*** As Chronic Wasting Disease CWD rises in deer herd, what about risk for
humans?
remember that healthy looking deer ?
sub-clinical CWD !
Research Article
Detection of Sub-Clinical CWD Infection in Conventional Test-Negative Deer
Long after Oral Exposure to Urine and Feces from CWD+ Deer
Nicholas J. Haley, Affiliation: Department of Microbiology, Immunology, and
Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado
State University, Fort Collins, Colorado, United States of America
X Candace K. Mathiason, Affiliation: Department of Microbiology,
Immunology, and Pathology, College of Veterinary Medicine and Biomedical
Sciences, Colorado State University, Fort Collins, Colorado, United States of
America
X Mark D. Zabel, Affiliation: Department of Microbiology, Immunology, and
Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado
State University, Fort Collins, Colorado, United States of America
X Glenn C. Telling, Affiliation: Department of Molecular Biology and
Genetics, University of Kentucky, Lexington, Kentucky, United States of America
X Edward A. Hoover mail * E-mail: Edward.Hoover@colostate.edu
Affiliation: Department of Microbiology, Immunology, and Pathology, College
of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort
Collins, Colorado, United States of America
X
Abstract Background Chronic wasting disease (CWD) of cervids is a prion
disease distinguished by high levels of transmissibility, wherein bodily fluids
and excretions are thought to play an important role. Using cervid bioassay and
established CWD detection methods, we have previously identified infectious
prions in saliva and blood but not urine or feces of CWD+ donors. More recently,
we identified very low concentrations of CWD prions in urine of deer by cervid
PrP transgenic (Tg[CerPrP]) mouse bioassay and serial protein misfolding cyclic
amplification (sPMCA). This finding led us to examine further our initial cervid
bioassay experiments using sPMCA.
Objectives We sought to investigate whether conventional test-negative
deer, previously exposed orally to urine and feces from CWD+ sources, may be
harboring low level CWD infection not evident in the 19 month observation
period. We further attempted to determine the peripheral PrPCWD distribution in
these animals.
Methods Various neural and lymphoid tissues from conventional test-negative
deer were reanalyzed for CWD prions by sPMCA and cervid transgenic mouse
bioassay in parallel with appropriate tissue-matched positive and negative
controls.
Results PrPCWD was detected in the tissues of orally exposed deer by both
sPMCA and Tg[CerPrP] mouse bioassay; each assay revealed very low levels of CWD
prions previously undetectable by western blot, ELISA, or IHC. Serial PMCA
analysis of individual tissues identified that obex alone was positive in 4 of 5
urine/feces exposed deer. PrPCWD was amplified from both lymphoid and neural
tissues of positive control deer but not from identical tissues of negative
control deer.
Discussion Detection of subclinical infection in deer orally exposed to
urine and feces (1) suggests that a prolonged subclinical state can exist,
necessitating observation periods in excess of two years to detect CWD
infection, and (2) illustrates the sensitive and specific application of sPMCA
in the diagnosis of low-level prion infection. Based on these results, it is
possible that low doses of prions, e.g. following oral exposure to urine and
saliva of CWD-infected deer, bypass significant amplification in the LRS,
perhaps utilizing a neural conduit between the alimentary tract and CNS, as has
been demonstrated in some other prion diseases.
Citation: Haley NJ, Mathiason CK, Zabel MD, Telling GC, Hoover EA (2009)
Detection of Sub-Clinical CWD Infection in Conventional Test-Negative Deer Long
after Oral Exposure to Urine and Feces from CWD+ Deer. PLoS ONE 4(11): e7990.
doi:10.1371/journal.pone.0007990
Editor: Jiyan Ma, Ohio State University, United States of America
Received: September 29, 2009; Accepted: October 29, 2009; Published:
November 24, 2009
Copyright: © 2009 Haley et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the
original author and source are credited.
Funding: This work was supported by NIH/NCRR Ruth L. Kirschstein
Institutional T32 R07072-03 and NIH/NIAID NO1-AI-25491-02 (EAH, GCT). The
funders had no role in study design, data collection and analysis, decision to
publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests
exist.
Tuesday, June 16, 2009
Infectious Prions in Pre-Clinical Deer and Transmission of Chronic Wasting
Disease Solely by Environmental Exposure
Friday, August 09, 2013
***PRION2013 CONGRESSIONAL ABSTRACTS
CWD TSE prion, plants, vegetables, and the potential for environmental
contamination
Sunday, September 01, 2013
hunting over gut piles and CWD TSE prion disease
Sunday, June 09, 2013
Missouri House forms 13-member Interim Committee on the Cause and Spread of
Chronic Wasting Disease CWD
Wednesday, August 21, 2013
IOWA DNR EMERGENCY CONSENT ORDER IN THE MATTER OF TOM & LINDA BRAKKE
D/B/A PINE RIDGE HUNTING LODGE UPDATE AUGUST 21, 2013
Saturday, September 07, 2013
Georgia House Bill 1043 and Chronic Wasting Disease CWD
Greetings Honorable Representatives of the House, Game, Fish, & Parks,
Tuesday, October 23, 2012
PA Captive deer from CWD-positive farm roaming free
USDA TO PGC ONCE CAPTIVES ESCAPE "it‘s no longer its business.”
Sunday, January 06, 2013
USDA TO PGC ONCE CAPTIVES ESCAPE "it‘s no longer its business.”
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.
Monday, June 24, 2013
The Effects of Chronic Wasting Disease on the Pennsylvania Cervid Industry
Following its Discovery
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
Friday, August 02, 2013
The Fight to Keep Chronic Wasting Disease Out of Florida
FWC passes rule prohibiting importation of deer News Release
Friday, September 06, 2013
Media contact: Susan Smith, 850-488-8843
(Back to Commission meeting news)
The Florida Fish and Wildlife Conservation Commission (FWC) at its
Pensacola commission meeting today, Sept. 6, passed a rule prohibiting the
importation of live captive deer into Florida from out-of-state sources.
The rule was passed in an effort to reduce the chances of chronic wasting
disease (CWD) being introduced into the state. Eighteen other states, including
Georgia and Alabama, also prohibit the importation of live cervids (deer, elk
and moose).
CWD is not known to affect people but is a contagious neurological disease
affecting cervids. It is always fatal, and there is no known cure or vaccine. So
far, the disease has been discovered in 22 states, two Canadian provinces and in
South Korea.
To implement the decision immediately, the FWC also issued an executive
order prohibiting importation of cervids effective today, Sept. 6, 2013. The
order includes limited exemptions for reindeer and zoos.
The Commission also directed the executive director to create a working
group to include the industry to develop other measures to safeguard the state
from CWD. If these other measures are determined to be sufficient to adequately
reduce risk, the Commission gives the executive director authority to then allow
importation.
Since the beginning of May, the FWC has received much public comment on
this and answered questions and concerns. During this process, those who have
deer farms and hunting preserves , hunters and conservationists provided
suggestions for additional prevention measures to consider. The Commission used
this important feedback to guide its decision making.
For more information on chronic wasting disease, this rule and the CWD
Alliance, go to MyFWC.com/CWD. To see the executive order, go to MyFWC.com/About
and select “Inside FWC” then “Executive Director.”
ORDER NUMBER: EO 13-31
Sunday, August 11, 2013
Creutzfeldt-Jakob Disease CJD cases rising North America updated report
August 2013
Creutzfeldt-Jakob Disease CJD cases rising North America with Canada seeing
an extreme increase of 48% between 2008 and 2010
Friday, August 16, 2013
*** Creutzfeldt-Jakob disease (CJD) biannual update August 2013 U.K. and
Contaminated blood products induce a highly atypical prion disease devoid of
PrPres in primates
Sunday, September 08, 2013
Iatrogenic Creutzfeldt-Jakob disease via surgical instruments and
decontamination possibilities for the TSE prion
*** The potential impact of prion diseases on human health was greatly
magnified by the recognition that interspecies transfer of BSE to humans by beef
ingestion resulted in vCJD. While changes in animal feed constituents and
slaughter practices appear to have curtailed vCJD, there is concern that CWD of
free-ranging deer and elk in the U.S. might also cross the species barrier.
Thus, consuming venison could be a source of human prion disease. Whether BSE
and CWD represent interspecies scrapie transfer or are newly arisen prion
diseases is unknown. Therefore, the possibility of transmission of prion disease
through other food animals cannot be ruled out. There is evidence that vCJD can
be transmitted through blood transfusion. There is likely a pool of unknown size
of asymptomatic individuals infected with vCJD, and there may be asymptomatic
individuals infected with the CWD equivalent. These circumstances represent a
potential threat to blood, blood products, and plasma supplies.
TSS
posted by Terry S. Singeltary Sr. at
12:00 AM
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