TEXAS A&M AGRILIFE EXTENSION A Guide to Chronic Wasting Disease (CWD) in Texas Cervids
TEXAS A&M AGRILIFE EXTENSION
A Guide to Chronic Wasting Disease (CWD) in Texas Cervids
John M. Tomeček Ph.D., Assistant Professor and Extension Wildlife
Specialist, Department of Wildlife and Fisheries Sciences, Texas A&M
University
Terry Hensley MS., DVM, Assistant Agency Director and Extension
Veterinarian, Texas A&M Veterinary Medicine Diagnostic Laboratory, Texas
A&M University
Walt E. Cook Ph.D., DVM, Clinical Associate Professor, Department of
Veterinary Pathobiology, Texas A&M University
Bob Dittmar DVM, Wildlife Veterinarian, Texas Parks and Wildlife
Department
1
Chronic Wasting Disease (CWD) has a dramatic impact on cervid* management
in regions where it occurs. For wildlife professionals and veterinarians, the
disease presents clear challenges. For people engaged in hunting or
hunting-related businesses, the disease creates serious concerns soon after it
is discovered in their area.
CWD has been present in far west Texas since 2012, but because early
infections were in remote areas, the disease is still little understood
throughout most of the state. Some information about CWD has been distorted, and
myths have circulated through the general public. Given CWD’s potential threat
to cervid populations, and the consequent economic impacts related to hunting,
the people of Texas need to have an accurate understanding of the disease, its
diagnosis, management, and implications for the future.
What is Chronic Wasting Disease?
CWD affects the nervous system in cervids—that is, mule deer, white-tailed
deer, elk, and moose. It is one disease in a family called the transmissible
spongiform encephalopathies (TSEs), such as scrapie in domestic sheep and goats,
bovine spongiform encephalopathy (BSE), and Creutzfeldt-Jakob Disease (CJD) in
humans. CWD only infects cervids and, like most TSEs, cannot naturally be
transmitted to noncervid hosts. As its name suggests, CWD causes slow
progressive weight loss and degraded body condition, abnormal behavior, and
ultimately death1. These symptoms are caused by the deposition of abnormal
proteins (prions) in nervous system tissues. These abnormal prion proteins
accumulate and then interrupt nervous system functions.
Cervid populations in Texas include native species (white-tailed deer, mule
deer, and elk) as well as exotics (red deer, roe deer, sika, axis). Given the
size and diversity of these populations, this disease could potentially affect
many animals. History of Chronic Wasting Disease
The precise location and mode of CWD development is not known. The
condition was first noted in 1967 in research mule deer herds in Colorado, but
not confirmed as a TSE until 1978. By the late 1970s, CWD was recognized in
Colorado and Wyoming in captive mule deer, black-tailed deer, and elk. In 1981,
the disease was identified in wild elk in Colorado, and
*Underlined terms are in the glossary on page 9 Photo source: Dr. Terry
Kreeger, Wyoming Game and Fish Department
2
shortly thereafter in Wyoming elk. In 1985, it was identified in mule deer
in Colorado and Wyoming and in white-tailed deer of both states in 1990. At that
point, an endemic zone for the disease was established in those states. CWD was
not detected outside that endemic zone until 1996.
In the mid-1990s, CWD spread to captive herds in Oklahoma, Nebraska and
Saskatchewan. Wild cervids in Saskatchewan were affected by 2000. In 2001, CWD
was identified in wild white-tailed deer in South Dakota and in a captive herd
in Nebraska. In the early 2000s, CWD spread across New Mexico, Illinois,
Alberta, Wisconsin, Utah, Kansas, and New York.
Growing concern precipitated the creation of CWD control efforts at the
federal level. Additional funding was directed toward researching the disease
and developing better testing methods. In the 2010s, the disease expanded into
Virginia, Missouri, Minnesota, Texas, Iowa, Ohio, and Pennsylvania. In 2015,
Michigan confirmed the first case of CWD in wild white-tailed deer. Currently 23
states and two Canadian provinces have CWD infections in elk, white-tailed deer,
moose, red deer, and black-tailed deer2.
Photo source: U.S. Geological Survey, http://www.nwhc.usgs.gov/disease_information/chronic_wasting_disease/
3
Chronic Wasting Disease in Texas
The Texas Parks and Wildlife Department (TPWD) has sampled for CWD since
2002 from hunter harvest, road kill and clinical animals. This sampling
represents Texas’ proactive stance on the issue. To date, more than 32,000
samples have been collected from free-ranging white-tailed and mule deer across
the state. More than 12,000 samples have been collected by permitted deer
breeders in Texas as part of the surveillance program to move deer. In 2012, CWD
was detected in free-ranging mule deer in the Hueco Mountains in El Paso and
Hudspeth counties in West Texas. To contain the disease, TPWD responded by
restricting unnatural movement of animals and imposing mandatory sampling of
hunter harvested animals in the area. Enhanced surveillance continues in that
area to determine the extent of the disease. To date, seven mule deer have
tested positive for CWD—all have been located in the Hueco Mountains area.
In July 2015, TPWD and the Texas Animal Health Commission confirmed a case
of CWD in a captive white-tailed deer in Medina County. This was the first
identified instance of the disease in captive white-tailed deer in Texas.
Follow-up testing found three more positive animals in the herd. A deer from
this facility that was moved to another facility, subsequently also tested
positive—for a total of five. Efforts are underway to determine the source of
the animal’s infection, test animals that have left the index facility and to
formulate management strategies. TPWD is also increasing surveillance of
free-ranging deer throughout the state.
Epidemiology
Clinical Signs
The most obvious clinical sign of CWD is the progressive loss of weight and
body condition, despite continued feeding activity. However, cervids may show
subtle behavior and coat abnormalities before weight loss becomes notable. As
the disease progresses, infected animals may drink and urinate excessively.
Behavior alters significantly as the disease progresses, and may include
sluggishness, decreased activity, blank expressions, sawhorse stance, and
repetitive movement patterns. In some cases, animals may drool excessively and
grind their teeth.
It was thought that the disease incubated for 16 months before the animal
showed clinical signs. Then animal sheds of infected prions could beginning from
16 to 36 months1. More recent research indicates that transmission is possible
through prions shed in feces in less than 16 months3. This suggests that
individuals that appear healthy can still transmit CWD. The presence of signs
alone, however, is not a clear diagnosis of the disease because other disorders
can cause similar signs.
Photo source: Dr. Terry Kreeger, Wyoming Game and Fish Department
4
Transmission
CWD is transmitted through direct animal-to-animal contact or indirect
contact with prion-contaminated feces, urine, or saliva from infected
individuals. Animals are typically 3 to 4 years old before clinical signs
appear, but there are documented cases of first signs of the disease showing in
animals as young as 18 months and as old as 13 years. It is uncommon for
yearlings to exhibit clinical signs. Speculation holds that males can be exposed
when removing antler velvet by rubbing this soft tissue on structures in the
environment. Exposure to prions from other aspects of the rut is likely more
important. Infectious agents shed into the environment from carcasses are likely
also important4,5. Recent research indicates that some plant structures may
retain infected prions from these transmission routes, preserve them in the
environment, and act as reservoirs for the disease6. How important this
reservoir mechanism is to maintaining or spreading CWD is unknown.
Previous efforts to eradicate CWD from captive cervid facilities prove the
infectious agents can remain infectious in the environment for years. They are
difficult, if not impossible, to inactivate or remove under current management
and disinfection strategies. For this reason, indirect transmission may be more
important than direct transmission. Cervid-dense areas, such as holding pens or
supplemental feeding stations may serve as transmission hot spots. The movement
of live animals or infected carcasses may cause the disease to spread over long
distances. Though experts speculate that initial transmission occurred when
captive cervids came into contact with wild populations, no clear evidence
supports this notion. Furthermore, it is now likely that transmission between
wild and captive populations has occurred in both directions. This disease,
however, is limited to deer and related species, and there is no reason to
believe it can be transmitted to domestic livestock7.
Diagnosis
Though animals may be infected for some time, clinical signs are usually
the first indication that an animal may have the disease. Clinical signs,
therefor, are evidence that an animal is in late infection and should be taken
seriously. Unfortunately, these signs can be difficult to distinguish from other
cervid diseases, such as chronic hemorrhagic disease, brain abscess, meningitis,
encephalitis, malnutrition, and pneumonia. The only definitive diagnosis must
come from laboratory testing of brain, lymph node, or tonsil tissue from
sacrificed animals. Live animal tests have been used in research, but are not
currently approved for
Photo source: Wisconsin Department of Natural Resources
5
public use by regulatory agencies. Although lesions may appear on the
animal as a result of weight loss and degraded body condition, the only way to
definitively diagnose CWD is by identifying lesions and prion deposition in
nervous or lymphoid tissues at a microscopic level. Necropsy often indicates
aspiration pneumonia as the ultimate cause of death. For this reason, it is
important to test for CWD when any deer appears to die of pneumonia.
Testing procedures
If you want to have an animal tested, contact your local Texas Parks and
Wildlife Department wildlife biologist first. You must deliver specific intact
tissues to the laboratory and taking samples requires specific training and
experience. In most cases, brain stem tissue called the obex is used to test for
CWD prions. Another important tissue is the medial retropharyngeal lymph nodes
(RLN). In deer, the prions will usually show up in the RLN before the obex. The
obex and RLN must be removed from the carcass and placed in a 10 percent
formalin solution for transport to the laboratory. Samples must not be frozen.
If you are not trained to collect these samples or are uncomfortable with the
process, you may submit the entire head, with identification attached, to the
Texas A&M Veterinary Medical Diagnostic Laboratory for testing.
Contact the Texas A&M Veterinary Medical Diagnostic Laboratory for
instructions on taking and submitting samples. In many cases, your local
veterinarian can help you properly collect and ship samples to the lab. You are
responsible for testing costs.
Treatment and herd management
Currently, there is no treatment for this disease. While there has been
some preliminary success in vaccinating white-tailed deer in New York8, and
research in Canada is ongoing, no vaccine has proven effective. The potential
for natural genetic immunity has been considered, such as occurs with domestic
sheep and goats with the TSE scrapie. To date, research has found no individuals
from CWD susceptible species that are truly immune. Although there is no
vaccination or treatment for CWD, a number of states and provinces have adopted
management practices to reduce the disease’s prevalence and limit its
transmission. These practices are not specific to free-roaming or captive
deer—they apply to all at-risk cervids. The following outlines the benefits,
challenges, and implementation of a few of these practices.
Density Management
This practice seeks to limit the spread of the disease by decreasing animal
density to levels where transmission would be minimal. While reducing densities
cannot eradicate established CWD, it may reduce the disease’s prevalence and
slow its spread.
Photo source: Wisconsin Department of Natural Resources
6
The target densities often reflect scientific estimates of densities that
would occur naturally—uninfluenced by human activities. These target densities
can be achieved through lethal or nonlethal removal of animals or habitat
modification. Removing animals can reduce densities in wild or captive
populations. Although this strategy likely is the most effective at slowing the
spread of CWD into a region, other states have indicated that it is difficult to
maintain hunter-performed density-management for periods exceeding 5 years9.
Agency based culling, though very unpopular, could be used on private properties
to some effect.
Bait and feed removal/modification
Reducing the availability and frequency of supplemental feeds or bait helps
limit transmission by limiting sites where cervids congregate. While this
practice can be effective, it can also have a negative impact on hunting
businesses that rely on bait sites to attract game animals consistently. This
practice is very easy to implement, but often is unpopular. One possible
modification is to have landowners move bait and feeding sites frequently to
prevent infectious agent buildup in the soil. Another possibility is to
discontinue baiting and feeding during certain times of the year. Feeders that
do not allow feed to contact the soil, may reduce environmental contamination
and disease transmission.
Selective Removal
Animals that display clinical symptoms of CWD, should be lethally removed
from the herd, tested, and disposed of safely to minimize exposing other animals
to the disease. This practice maximizes the number of deer in the herd while
removing those most likely to be infected. This method, however, does not remove
animals before they could potentially transmit the disease. Research suggests
that this model could significantly reduce disease prevalence, provided infected
animals could be identified and removed10. This practice may not be practical in
large, sparsely populated areas of Texas. Human health and safety
precautions
For the General Public
There is no evidence that CWD can be transmitted to humans—there is ample
evidence to suggest it cannot be transmitted to humans. While some have been
concerned that exposure to infected deer would increase cases of
Creutzfeldt-Jakob syndrome, this has not occurred in areas where CWD is
considered endemic11. There is also no indication that it can be transmitted to
domestic livestock such as sheep or cattle, unlike BSE (Mad Cow), which caused
widespread human health concerns in Great Britain. Nevertheless, experts advise
caution as we learn more about the disease12.
7
Given the development and evolution of zoonotic diseases, human exposure to
animals potentially infected with any disease should be minimized. Those who
process and handle meat from animals killed in areas where CWD is present should
follow the practices outlined below to limit exposure. If you suspect an animal
might be infected, contact the appropriate government agencies immediately. See
“Resources” on page 13 for contact information.
For Hunters
CWD affects the nervous system of infected animals and hunters may feel
uneasy about eating meat from cervids in areas where CWD has been documented.
However, we know that tens of thousands, possibly hundreds of thousands of
hunters and their families have eaten deer and elk from endemic areas over the
past decades without incident. Concerns over the disease should not keep you
from the hunt for several reasons.
First, even in some of the highest-prevalence areas of Wyoming and
Colorado, fewer than 30 percent of wild cervids are typically infected. In
Texas, only a dozen cases have been documented across the entire state as of 1
October 2015. Second, hunting is also one of the best, and simplest, tools for
reducing densities of cervids to prevent disease transmission. Texas hunters
have a long history of supporting conservation by conscientious hunting to
benefit animal health and habitats.
Employing basic wild game meat safety should address any concerns you may
have. The simple precautions outlined below can keep the hunter and family stay
safe. These precautions assume that hunters comply with state regulations
regarding the location and timing of game harvest and processing.
• Do not harvest animals that exhibit clinical signs of CWD or any other
disease.
• When processing harvested game, wear protective gloves, and avoid contact
with nervous system tissues.
• Do not consume brain or organ meats, especially lymph nodes from the head
of cervids.
• Bone out the meat, and make sure to minimize contact with the brain and
spine—they constitute the bulk of the nervous system where prions tend to
concentrate.
• Dispose of all nonconsumable parts securely in a location where other
cervids will not be exposed to the carcass, for example, in an approved landfill
or buried at least 6 feet deep.
• Cleaning processing equipment in a 50 percent chlorine bleach solution
will destroy prions, but is very harmful
Photo source: Wisconsin Department of Natural Resources 8
to most equipment. Cleaning equipment with hot soapy water is typically
sufficient, given the limited health risks to humans. Wipe down processing
surfaces with the same solution on a clean cloth. The future of cervid hunting
in Texas
CWD has now been diagnosed in two cervid species in Texas. The nature of
CWD, makes eradication unlikely once it takes hold in a region. The best
management practices continue to be those that minimize disease transmission.
Given that cervid hunting in Texas is economically and culturally important,
especially in rural communities, concern for the future of this enterprise is
understandable. In regions where CWD is endemic, such as Colorado and Wyoming,
cervid hunting continues to be a very desirable commodity whose value has not
decreased. Some are quick to note the decline of mule deer populations in the
CWD-infected Rocky Mountain states, however, these declines could be attributed
to factors such as prolonged drought, habitat degradation, and other factors. In
addition, many mule deer populations are declining for reasons other than CWD.
No one knows what effect CWD will have on Texas hunting, or if this disease will
cause notable changes to hunting practices. What does seem certain is that
cervid hunting in Texas will continue to be important, and that management based
on the latest science will continue.
If you think an animal is infected
1. Do not attempt to touch, kill, or move the animal in any way.
2. Carefully document the location of the animal, and any other pertinent
details.
3. Contact the nearest Texas Parks and Wildlife Game Warden or Biologist or
the Texas Animal Health Commission.
4. Follow the instructions given by those agencies.
5. Continue to be vigilant for potentially infected animals.
Photo source: Wisconsin Department of Natural Resources 9
Glossary
Cervid – Any member of the family Cervidae, including deer, elk, and
moose.
Endemic – A condition regularly found in a certain area.
Obex – Portion of the brain where the brain narrows to become the central
canal of the spinal cord; located in the caudal medulla.
Prion – A malformed protein particle associated with various brain
diseases, including TSEs.
Shedding – When a disease produces infectious agents that can infect other
hosts.
Transmissible Spongiform Encephalopathy (TSE) – A disease of the nervous
system, caused by the presence of prions. They are distinguished by long
incubation periods, characteristic spongiform changes associated with neuronal
loss, and a failure to induce inflammatory response.
Velvet – In this context, the soft, blood-vessel-rich tissue that forms
antlers annually. When bony growth has finished, this tissue is shed by rubbing
it on tree trunks, branches, and other structures.
Zoonotic – A disease that can be transmitted between humans and animals.
These diseases typically infect animals, but can also infect humans.
Resources
Texas Parks and Wildlife Department
www.tpwd.texas.gov
(512) 389-4800
Texas Animal Health Commission
www.tahc.texas.gov
1-800-550-8242
Texas A&M Veterinary Medicine Diagnostic Laboratory
www.tvmdl.tamu.edu
Chronic Wasting Disease Alliance
www.cwd-info.org
Texas A&M AgriLife Extension: Wildlife Unit
www.wildlife.tamu.edu
10
References 1 Williams, E. S., M. W. Miller, T. J. Kreeger, R. H. Kahn, and
E. T. Thorne. 2002. Chronic Wasting Disease of Deer and Elk: A Review with
Recommendations for Management. The Journal of Wildlife Management 66:551-563. 2
Schwabenlander, M. D., M. R. Culhane, S. M. Hall, S. M. Goyal, P. L. Anderson,
M. Carstensen, S. J. Wells, W. B. Slade, and A. G. Armien. 2013. A case of
chronic wasting disease in a captive red deer (Cervus elaphus). J Vet Diagn
Invest 25:573-576. 3 Tamguney, G., M. W. Miller, L. L. Wolfe, T. M. Sirochman,
D. V. Glidden, C. Palmer, A. Lemus, S. J. DeArmond, and S. B. Prusiner. 2009.
Asymptomatic deer excrete infectious prions in faeces. Nature 461:529-532. 4
Gough, K. C., and B. C. Maddison. 2010. Prion transmission: Prion excretion and
occurrence in the environment. Prion 4:275-282. 5 Samuel, E. S., L. B.-H.
Shannon, and C. B. Jason. 2012. Occurrence, Transmission, and Zoonotic Potential
of Chronic Wasting Disease. Emerging Infectious Disease journal 18:369. 6
Pritzkow, S., R. Morales, F. Moda, U. Khan, Glenn C. Telling, E. Hoover, and C.
Soto. 2015. Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions.
Cell Reports 11:1168-1175. 7 Hamir, A. N., R. C. Cutlip, J. M. Miller, E. S.
Williams, M. J. Stack, M. W. Miller, K. I. O’Rourke, and M. J. Chaplin. 2001.
Preliminary findings on the experimental transmission of chronic wasting disease
agent of mule deer to cattle. Journal of Veterinary Diagnostic Investigation
13:91-96. 8 Goni, F., C. K. Mathiason, L. Yim, K. Wong, J. Hayes-Klug, A. Nalls,
D. Peyser, V. Estevez, N. Denkers, J. Xu, D. A. Osborn, K. V. Miller, R. J.
Warren, D. R. Brown, J. A. Chabalgoity, E. A. Hoover, and T. Wisniewski. 2015.
Mucosal immunization with an attenuated Salmonella vaccine partially protects
white-tailed deer from chronic wasting disease. Vaccine 33:726-733. 9 Brown, T.
L., J. Shanahan, D. Decker, W. Siemer, P. Curtis, and J. Major. 2005. Response
of hunters and the general public to the discovery of chronic wasting disease in
deer in Oneida County, New York. Human Dimensions Research Unit, Department of
Natural Resource Cornell University Series 5-08. 10 Wasserberg, G., E. E. Osnas,
R. E. Rolley, and M. D. Samuel. 2009. Host culling as an adaptive management
tool for chronic wasting disease in white-tailed deer: a modelling study. The
Journal of Applied Ecology 46:457-466. 11 MaWhinney, S., W. J. Pape, J. E.
Forster, C. A. Anderson, P. Bosque, and M. W. Miller. 2006. Human prion disease
and relative risk associated with chronic wasting disease. Emerging Infectious
Diseases 12:1527. 12 Saunders, S. E., S. L. Bartelt-Hunt, and J. C. Bartz. 2012.
Occurrence, transmission, and zoonotic potential of chronic wasting disease.
Emerging Infectious Diseases 18:369-376.
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Cooperating.
Greetings Texas Hunters et al,
let’s analyize a few myths Texas A&M et al like to pass on to the
public about the CWD TSE Prion
Texas A&M Myth Number 1
>>> There is no evidence that CWD can be transmitted to
humans—there is ample evidence to suggest it cannot be transmitted to humans.
<<<
now, before getting into the latest sound science on the potential
transmission of CWD TSE Prion to humans, and the likelihood therefrom, IF it has
not already happened. I assure you that the FDA did not recall all this Elk
Tenderloin that was confirmed to have had CWD, the FDA did not recall all this
meat, FOR THE HEALTH OF THE DEAD CWD INFECTED ELK, recalled right here in
Texas...
Exotic Meats USA Announces Urgent Statewide Recall of Elk Tenderloin
Because It May Contain Meat Derived From An Elk Confirmed To Have Chronic
Wasting Disease
Contact: Exotic Meats USA 1-800-680-4375
FOR IMMEDIATE RELEASE -- February 9, 2009 -- Exotic Meats USA of San
Antonio, TX is initiating a voluntary recall of Elk Tenderloin because it may
contain meat derived from an elk confirmed to have Chronic Wasting Disease
(CWD). The meat with production dates of December 29, 30 and 31, 2008 was
purchased from Sierra Meat Company in Reno, NV. The infected elk came from Elk
Farm LLC in Pine Island, MN and was among animals slaughtered and processed at
USDA facility Noah’s Ark Processors LLC.
Chronic Wasting Disease (CWD) is a fatal brain and nervous system disease
found in elk and deer. The disease is caused by an abnormally shaped protein
called a prion, which can damage the brain and nerves of animals in the deer
family. Currently, it is believed that the prion responsible for causing CWD in
deer and elk is not capable of infecting humans who eat deer or elk contaminated
with the prion, but the observation of animal-to-human transmission of other
prion-mediated diseases, such as bovine spongiform encephalopathy (BSE), has
raised a theoretical concern regarding the transmission of CWD from deer or elk
to humans. At the present time, FDA believes the risk of becoming ill from
eating CWD-positive elk or deer meat is remote. However, FDA strongly advises
consumers to return the product to the place of purchase, rather than disposing
of it themselves, due to environmental concerns.
Exotic Meats USA purchased 1 case of Elk Tenderloins weighing 16.9 lbs. The
Elk Tenderloin was sold from January 16 – 27, 2009. The Elk Tenderloins was
packaged in individual vacuum packs weighing approximately 3 pounds each. A
total of six packs of the Elk Tenderloins were sold to the public at the Exotic
Meats USA retail store. Consumers who still have the Elk Tenderloins should
return the product to Exotic Meats USA at 1003 NE Loop 410, San Antonio, TX
78209. Customers with concerns or questions about the Voluntary Elk Recall can
call 1-800-680-4375. The safety of our customer has always been and always will
be our number one priority.
Exotic Meats USA requests that for those customers who have products with
the production dates in question, do not consume or sell them and return them to
the point of purchase. Customers should return the product to the vendor. The
vendor should return it to the distributor and the distributor should work with
the state to decide upon how best to dispose. If the consumer is disposing of
the product he/she should consult with the local state EPA office.
#
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.
Presence and Seeding Activity of Pathological Prion Protein (PrPTSE) in
Skeletal Muscles of White-Tailed Deer Infected with Chronic Wasting
Disease
Martin L. Daus1, Johanna Breyer2, Katja Wagenfuehr1, Wiebke M. Wemheuer2,
Achim Thomzig1, Walter J. Schulz-Schaeffer2, Michael Beekes1*
1 P24 - Transmissible Spongiform Encephalopathies, Robert Koch-Institut,
Berlin, Germany, 2 Prion and Dementia Research Unit, Department of
Neuropathology, University Medical Center Go¨ ttingen, Go¨ ttingen,
Germany
Abstract
Chronic wasting disease (CWD) is a contagious, rapidly spreading
transmissible spongiform encephalopathy (TSE), or prion disease, occurring in
cervids such as white tailed-deer (WTD), mule deer or elk in North America.
Despite efficient horizontal transmission of CWD among cervids natural
transmission of the disease to other species has not yet been observed. Here, we
report for the first time a direct biochemical demonstration of pathological
prion protein PrPTSE and of PrPTSE-associated seeding activity, the static and
dynamic biochemical markers for biological prion infectivity, respectively, in
skeletal muscles of CWD-infected cervids, i. e. WTD for which no clinical signs
of CWD had been recognized. The presence of PrPTSE was detected by Western- and
postfixed frozen tissue blotting, while the seeding activity of PrPTSE was
revealed by protein misfolding cyclic amplification (PMCA). Semi-quantitative
Western blotting indicated that the concentration of PrPTSE in skeletal muscles
of CWD-infected WTD was approximately 2000-10000 -fold lower than in brain
tissue. Tissue-blot-analyses revealed that PrPTSE was located in
muscle-associated nerve fascicles but not, in detectable amounts, in myocytes.
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.
snip...
Yet, it has to be noted that our assessments of PrPTSE levels in skeletal
muscles were based on findings in presumably pre- or subclinically infected
animals. Therefore, the concentration of PrPTSE in skeletal muscles of WTD with
clinically manifest CWD may possibly exceed our estimate which refers to
clinically inconspicuous animals that are more likely to enter the human food
chain. Our tissue blot findings in skeletal muscles from CWDinfected WTD would
be consistent with an anterograde spread of CWD prions via motor nerve fibres to
muscle tissue (figure 4A). Similar neural spreading pathways of muscle infection
were previously found in hamsters orally challenged with scrapie [28] and
suggested by the detection of PrPTSE in muscle fibres and muscle-associated
nerve fascicles of clinically-ill non-human primates challenged with BSE prions
[29]. Whether the absence of detectable PrPTSE in myofibers observed in our
study is a specific feature of CWD in WTD, or was due to a pre- or subclinical
stage of infection in the examined animals, remains to be established. In any
case, our observations support previous findings suggesting the precautionary
prevention of muscle tissue from CWD-infected WTD in the human diet, and
highlight the need to comprehensively elucidate of whether CWD may be
transmissible to humans. While the understanding of TSEs in cervids has made
substantial progress during the past few years, the assessment and management of
risks possibly emanating from prions in skeletal muscles of CWD-infected cervids
requires further research.
Citation: Daus ML, Breyer J, Wagenfuehr K, Wemheuer WM, Thomzig A, et al.
(2011) Presence and Seeding Activity of Pathological Prion Protein (PrPTSE) in
Skeletal Muscles of White-Tailed Deer Infected with Chronic Wasting Disease.
PLoS ONE 6(4): e18345. doi:10.1371/journal.pone.0018345
Editor: Jason Bartz, Creighton University, United States of America
Received December 17, 2010; Accepted March 1, 2011; Published April 1,
2011
Copyright: 2011 Daus 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: The study was sponsored by the
Alberta Prion Research Institute (APRI, www.prioninstitute.ca), and the study
was carried out within the APRIsponsored research project ‘‘Comprehensive risk
assessment of Chronic Wasting Disease (CWD) transmission to humans using
non-human primates’’. 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.
* E-mail: BeekesM@rki.de
PRION 2016 TOKYO
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
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
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.
***********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
Monday, May 02, 2016
*** Zoonotic Potential of CWD Prions: An Update Prion 2016 Tokyo ***
*** PRION 2014 CONFERENCE CHRONIC WASTING DISEASE CWD
*** PPo3-7: Prion Transmission from Cervids to Humans is Strain-dependent
*** Here we report that a human prion strain that had adopted the cervid
prion protein (PrP) sequence through passage in cervidized transgenic mice
efficiently infected transgenic mice expressing human PrP,
*** indicating that the species barrier from cervid to humans is prion
strain-dependent and humans can be vulnerable to novel cervid prion strains.
PPo2-27:
Generation of a Novel form of Human PrPSc by Inter-species Transmission of
Cervid Prions
*** Our findings suggest that CWD prions have the capability to infect
humans, and that this ability depends on CWD strain adaptation, implying that
the risk for human health progressively increases with the spread of CWD among
cervids.
PPo2-7:
Biochemical and Biophysical Characterization of Different CWD Isolates
*** The data presented here substantiate and expand previous reports on the
existence of different CWD strains.
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.
>>>CHRONIC WASTING DISEASE , THERE WAS NO ABSOLUTE BARRIER TO
CONVERSION OF THE HUMAN PRION PROTEIN<<<
*** PRICE OF CWD TSE PRION POKER GOES UP 2014 ***
Transmissible Spongiform Encephalopathy TSE PRION update January 2, 2014
Wednesday, January 01, 2014
Molecular Barriers to Zoonotic Transmission of Prions
*** 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.
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
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.
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.
Scrapie to Humans USA?
1: Neuroepidemiology. 1985;4(4):240-9. Related Articles,
Links
Sheep consumption: a possible source of spongiform encephalopathy in
humans.
Davanipour Z, Alter M, Sobel E, Callahan M.
A fatal spongiform encephalopathy of sheep and goats (scrapie) shares many
characteristics with Creutzfeldt-Jakob disease (CJD), a similar dementing
illness of humans. To investigate the possibility that CJD is acquired by
ingestion of contaminated sheep products, we collected information on
production, slaughtering practices, and marketing of sheep in Pennsylvania. The
study revealed that sheep were usually marketed before central nervous system
signs of scrapie are expected to appear; breeds known to be susceptible to the
disease were the most common breeds raised in the area; sheep were imported from
other states including those with a high frequency of scrapie; use of veterinary
services on the sheep farms investigated and, hence, opportunities to detect the
disease were limited; sheep producers in the area knew little about scrapie
despite the fact that the disease has been reported in the area, and animal
organs including sheep organs were sometimes included in processed food.
Therefore, it was concluded that in Pennsylvania there are some 'weak links'
through which scrapie-infected animals could contaminate human food, and that
consumption of these foods could perhaps account for spongiform encephalopathy
in humans. The weak links observed are probably not unique to Pennsylvania.
PMID: 3915057 [PubMed - indexed for MEDLINE]
2015
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.
==============
Tuesday, December 16, 2014
*** 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 ;
***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.***
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
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to
nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep
and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were
exposed to the infectious agents only by their nonforced consumption of known
infectious tissues. The asymptomatic incubation period in the one monkey exposed
to the virus of kuru was 36 months; that in the two monkeys exposed to the virus
of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the
two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively.
Careful physical examination of the buccal cavities of all of the monkeys failed
to reveal signs or oral lesions. One additional monkey similarly exposed to kuru
has remained asymptomatic during the 39 months that it has been under
observation.
snip...
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie
by natural feeding to squirrel monkeys that we have reported provides further
grounds for concern that scrapie-infected meat may occasionally give rise in
humans to Creutzfeldt-Jakob disease.
PMID: 6997404
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract
Recently the question has again been brought up as to whether scrapie is
transmissible to man. This has followed reports that the disease has been
transmitted to primates. One particularly lurid speculation (Gajdusek 1977)
conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and
transmissible encephalopathy of mink are varieties of a single "virus". The U.S.
Department of Agriculture concluded that it could "no longer justify or permit
scrapie-blood line and scrapie-exposed sheep and goats to be processed for human
or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is
emphasised by the finding that some strains of scrapie produce lesions identical
to the once which characterise the human dementias"
Whether true or not. the hypothesis that these agents might be
transmissible to man raises two considerations. First, the safety of laboratory
personnel requires prompt attention. Second, action such as the "scorched meat"
policy of USDA makes the solution of the acrapie problem urgent if the sheep
industry is not to suffer grievously.
snip...
76/10.12/4.6
snip...see full text ;
Monday, May 02, 2016
*** Zoonotic Potential of CWD Prions: An Update Prion 2016 Tokyo ***
Wednesday, May 25, 2016
USDA APHIS National Scrapie TSE Prion Eradication Program April 2016
Monthly Report Prion 2016 Tokyo Update
***Moreover, sporadic disease has never been observed in breeding colonies
or primate research laboratories, most notably among hundreds of animals over
several decades of study at the National Institutes of Health25, and in nearly
twenty older animals continuously housed in our own facility.***
Texas A&M Myth Number 2
>>> There is also no indication that it can be transmitted to
domestic livestock such as sheep or cattle,<<<
Thursday, June 09, 2016
Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force Base
Scrapie TSE Prion Experiment 1964
Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force Base
Scrapie Experiment 1964
How Did CWD Get Way Down In Medina County, Texas?
Confucius ponders...
Could the Scrapie experiments back around 1964 at Moore Air Force near
Mission, Texas, could this area have been ground zero for CWD TSE Prion (besides
the CWD cases that have waltzed across the Texas, New Mexico border near WSMR
Trans Pecos region since around 2001)?
Epidemiology of Scrapie in the United States 1977
snip...
Scrapie Field Trial Experiments Mission, Texas
A Scrapie Field Trial was developed at Mission, Texas, to provide
additional information for the eradication program on the epidemiology of
natural scrapie. The Mission Field Trial Station is located on 450 acres of
pastureland, part of the former Moore Air Force Base, near Mission, Texas. It
was designed to bring previously exposed, and later also unexposed, sheep or
goats to the Station and maintain and breed them under close observation for
extended periods to determine which animals would develop scrapie and define
more closely the natural spread and other epidemiological aspects of the
disease.
The 547 previously exposed sheep brought to the Mission Station beginning
in 1964 were of the Cheviot, Hampshire, Montadale, or Suffolk breeds. They were
purchased as field outbreaks occurred, and represented 21 bloodlines in which
scrapie had been diagnosed. Upon arrival at the Station, the sheep were
maintained on pasture, with supplemental feeding as necessary. The station was
divided into 2 areas: (1) a series of pastures and-pens occupied by male animals
only, and (2) a series of pastures and pens occupied by females and young
progeny of both sexes. ...
snip...
DISCUSSION
Observations of natural outbreaks of scrapie indicated that the disease
spread from flock to flock by the movement of infected, but apparently normal,
sheep which were incubating the disease.
There was no evidence that the disease spread to adjacent flocks in the
absend of such movements or that vectors or other host species were involved in
the spread of scrapie to sheep or goats; however, these possibilities should be
kept open...
snip...see full text ;
Spongiform Encephalopathy in Captive Wild ZOO BSE INQUIRY
P.97: Scrapie transmits to white-tailed deer by the oral route and has a
molecular profile similar to chronic wasting disease and distinct from the
scrapie inoculum
Justin Greenlee1, S Jo Moore1, Jodi Smith1, M Heather West Greenlee2, and
Robert Kunkle1
1National Animal Disease Center; Ames, IA USA;
2Iowa State University; Ames, IA USA
The purpose of this work was to determine susceptibility of white-tailed
deer (WTD) to the agent of sheep scrapie and to compare the resultant PrPSc to
that of the original inoculum and chronic wasting disease (CWD). We inoculated
WTD by a natural route of exposure (concurrent oral and intranasal (IN); n D 5)
with a US scrapie isolate. All scrapie-inoculated deer had evidence of PrPSc
accumulation. PrPSc was detected in lymphoid tissues at preclinical time points,
and deer necropsied after 28 months post-inoculation had clinical signs,
spongiform encephalopathy, and widespread distribution of PrPSc in neural and
lymphoid tissues. Western blotting (WB) revealed PrPSc with 2 distinct molecular
profiles. WB on cerebral cortex had a profile similar to the original scrapie
inoculum, whereas WB of brainstem, cerebellum, or lymph nodes revealed PrPSc
with a higher profile resembling CWD. Homogenates with the 2 distinct profiles
from WTD with clinical scrapie were further passaged to mice expressing cervid
prion protein and intranasally to sheep and WTD. In cervidized mice, the 2
inocula have distinct incubation times. Sheep inoculated intranasally with WTD
derived scrapie developed disease, but only after inoculation with the inoculum
that had a scrapie-like profile. The WTD study is ongoing, but deer in both
inoculation groups are positive for PrPSc by rectal mucosal biopsy. In summary,
this work demonstrates that WTD are susceptible to the agent of scrapie, 2
distinct molecular profiles of PrPSc are present in the tissues of affected
deer, and inoculum of either profile readily passes to deer.
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Scrapie transmits to white-tailed deer by the oral route and has a
molecular profile similar to chronic wasting disease
Authors
item Greenlee, Justin item Moore, S - item Smith, Jodi - item Kunkle,
Robert item West Greenlee, M -
Submitted to: American College of Veterinary Pathologists Meeting
Publication Type: Abstract Only Publication Acceptance Date: August 12, 2015
Publication Date: N/A Technical Abstract: The purpose of this work was to
determine susceptibility of white-tailed deer (WTD) to the agent of sheep
scrapie and to compare the resultant PrPSc to that of the original inoculum and
chronic wasting disease (CWD). We inoculated WTD by a natural route of exposure
(concurrent oral and intranasal (IN); n=5) with a US scrapie isolate. All
scrapie-inoculated deer had evidence of PrPSc accumulation. PrPSc was detected
in lymphoid tissues at preclinical time points, and deer necropsied after 28
months post-inoculation had clinical signs, spongiform encephalopathy, and
widespread distribution of PrPSc in neural and lymphoid tissues. Western
blotting (WB) revealed PrPSc with 2 distinct molecular profiles. WB on cerebral
cortex had a profile similar to the original scrapie inoculum, whereas WB of
brainstem, cerebellum, or lymph nodes revealed PrPSc with a higher profile
resembling CWD. Homogenates with the 2 distinct profiles from WTD with clinical
scrapie were further passaged to mice expressing cervid prion protein and
intranasally to sheep and WTD. In cervidized mice, the two inocula have distinct
incubation times. Sheep inoculated intranasally with WTD derived scrapie
developed disease, but only after inoculation with the inoculum that had a
scrapie-like profile. The WTD study is ongoing, but deer in both inoculation
groups are positive for PrPSc by rectal mucosal biopsy. In summary, this work
demonstrates that WTD are susceptible to the agent of scrapie, two distinct
molecular profiles of PrPSc are present in the tissues of affected deer, and
inoculum of either profile readily passes to deer.
White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection
Jodi D. Smith, Justin J. Greenlee, and Robert A. Kunkle; Virus and Prion
Research Unit, National Animal Disease Center, USDA-ARS
Interspecies transmission studies afford the opportunity to better
understand the potential host range and origins of prion diseases. Previous
experiments demonstrated that white-tailed deer are susceptible to sheep-derived
scrapie by intracranial inoculation. The purpose of this study was to determine
susceptibility of white-tailed deer to scrapie after a natural route of
exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal
(1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep
clinically affected with scrapie. Non-inoculated deer were maintained as
negative controls. All deer were observed daily for clinical signs. Deer were
euthanized and necropsied when neurologic disease was evident, and tissues were
examined for abnormal prion protein (PrPSc) by immunohistochemistry (IHC) and
western blot (WB). One animal was euthanized 15 months post-inoculation (MPI)
due to an injury. At that time, examination of obex and lymphoid tissues by IHC
was positive, but WB of obex and colliculus were negative. Remaining deer
developed clinical signs of wasting and mental depression and were necropsied
from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and
WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal
and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work
demonstrates for the first time that white-tailed deer are susceptible to sheep
scrapie by potential natural routes of inoculation. In-depth analysis of tissues
will be done to determine similarities between scrapie in deer after
intracranial and oral/intranasal inoculation and chronic wasting disease
resulting from similar routes of inoculation.
see full text ;
PO-039: A comparison of scrapie and chronic wasting disease in
white-tailed deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture;
Agricultural Research Service, National Animal Disease Center; Ames, IA USA
White-tailed deer are susceptible to the agent of sheep scrapie by
intracerebral inoculation
snip...
It is unlikely that CWD will be eradicated from free-ranging cervids, and
the disease is likely to continue to spread geographically [10]. However, the
potential that white-tailed deer may be susceptible to sheep scrapie by a
natural route presents an additional confounding factor to halting the spread of
CWD. This leads to the additional speculations that
1) infected deer could serve as a reservoir to infect sheep with scrapie
offering challenges to scrapie eradication efforts and
2) CWD spread need not remain geographically confined to current endemic
areas, but could occur anywhere that sheep with scrapie and susceptible cervids
cohabitate.
This work demonstrates for the first time that white-tailed deer are
susceptible to sheep scrapie by intracerebral inoculation with a high attack
rate and that the disease that results has similarities to CWD. These
experiments will be repeated with a more natural route of inoculation to
determine the likelihood of the potential transmission of sheep scrapie to
white-tailed deer. If scrapie were to occur in white-tailed deer, results of
this study indicate that it would be detected as a TSE, but may be difficult to
differentiate from CWD without in-depth biochemical analysis.
2012
PO-039: A comparison of scrapie and chronic wasting disease in
white-tailed deer
Justin Greenlee, Jodi Smith, Eric Nicholson US Dept. Agriculture;
Agricultural Research Service, National Animal Disease Center; Ames, IA USA
snip...
The results of this study suggest that there are many similarities in the
manifestation of CWD and scrapie in WTD after IC inoculation including early and
widespread presence of PrPSc in lymphoid tissues, clinical signs of depression
and weight loss progressing to wasting, and an incubation time of 21-23 months.
Moreover, western blots (WB) done on brain material from the obex region have a
molecular profile similar to CWD and distinct from tissues of the cerebrum or
the scrapie inoculum. However, results of microscopic and IHC examination
indicate that there are differences between the lesions expected in CWD and
those that occur in deer with scrapie: amyloid plaques were not noted in any
sections of brain examined from these deer and the pattern of immunoreactivity
by IHC was diffuse rather than plaque-like.
*** After a natural route of exposure, 100% of WTD were susceptible to
scrapie.
Deer developed clinical signs of wasting and mental depression and were
necropsied from 28 to 33 months PI. Tissues from these deer were positive for
PrPSc by IHC and WB. Similar to IC inoculated deer, samples from these deer
exhibited two different molecular profiles: samples from obex resembled CWD
whereas those from cerebrum were similar to the original scrapie inoculum. On
further examination by WB using a panel of antibodies, the tissues from deer
with scrapie exhibit properties differing from tissues either from sheep with
scrapie or WTD with CWD. Samples from WTD with CWD or sheep with scrapie are
strongly immunoreactive when probed with mAb P4, however, samples from WTD with
scrapie are only weakly immunoreactive. In contrast, when probed with mAb’s 6H4
or SAF 84, samples from sheep with scrapie and WTD with CWD are weakly
immunoreactive and samples from WTD with scrapie are strongly positive. This
work demonstrates that WTD are highly susceptible to sheep scrapie, but on first
passage, scrapie in WTD is differentiable from CWD.
2011
*** After a natural route of exposure, 100% of white-tailed deer were
susceptible to scrapie.
White-tailed Deer are Susceptible to Scrapie by Natural Route of Infection
Jodi D. Smith, Justin J. Greenlee, and Robert A. Kunkle; Virus and Prion
Research Unit, National Animal Disease Center, USDA-ARS
Interspecies transmission studies afford the opportunity to better
understand the potential host range and origins of prion diseases. Previous
experiments demonstrated that white-tailed deer are susceptible to sheep-derived
scrapie by intracranial inoculation. The purpose of this study was to determine
susceptibility of white-tailed deer to scrapie after a natural route of
exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal
(1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep
clinically affected with scrapie. Non-inoculated deer were maintained as
negative controls. All deer were observed daily for clinical signs. Deer were
euthanized and necropsied when neurologic disease was evident, and tissues were
examined for abnormal prion protein (PrPSc) by immunohistochemistry (IHC) and
western blot (WB). One animal was euthanized 15 months post-inoculation (MPI)
due to an injury. At that time, examination of obex and lymphoid tissues by IHC
was positive, but WB of obex and colliculus were negative. Remaining deer
developed clinical signs of wasting and mental depression and were necropsied
from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and
WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal
and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work
demonstrates for the first time that white-tailed deer are susceptible to sheep
scrapie by potential natural routes of inoculation. In-depth analysis of tissues
will be done to determine similarities between scrapie in deer after
intracranial and oral/intranasal inoculation and chronic wasting disease
resulting from similar routes of inoculation.
see full text ;
Friday, April 22, 2016
*** Texas Scrapie Confirmed in a Hartley County Sheep where CWD was
detected in a Mule Deer
Thursday, June 09, 2016
Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force Base
Scrapie TSE Prion Experiment 1964
How Did CWD Get Way Down In Medina County, Texas?
Limited amplification of chronic wasting disease prions in the peripheral
tissues of intracerebrally inoculated cattle
Authors: Nicholas Haley1, Christopher Siepker2, Justin Greenlee3, Jürgen
Richt4
VIEW AFFILIATIONS Affiliations: 1 1Midwestern Univerisity 2 2Kansas State
University 3 3USDA, Agricultural Research Service 4 4Kansas State University
Published Ahead of Print: 31 March, 2016 Journal of General Virology doi:
10.1099/jgv.0.000438 Published Online: 31/03/2016
Chronic wasting disease (CWD) is a fatal neurodegenerative disease,
classified as a prion disease or transmissible spongiform encephalopathy (TSE)
similar to bovine spongiform encephalopathy (BSE). Cervids affected by CWD
accumulate an abnormal protease resistant prion protein throughout the central
nervous system (CNS), as well as in both lymphatic and excretory tissues - an
aspect of prion disease pathogenesis not observed in cattle with BSE. Using
seeded amplification through real time quaking induced conversion (RT-QuIC), we
investigated whether the bovine host or prion agent was responsible for this
aspect of TSE pathogenesis. We blindly examined numerous central and peripheral
tissues from cattle inoculated with CWD for prion seeding activity. Seeded
amplification was readily detected in the CNS, though rarely observed in
peripheral tissues, with a limited distribution similar to that of BSE prions in
cattle. This seems to indicate that prion peripheralization in cattle is a
host-driven characteristic of TSE infection.
Friday, August 14, 2015
Susceptibility of cattle to the agent of chronic wasting disease from elk
after intracranial inoculation
ARS VIRUS AND PRION RESEARCH / Research / Publication #277212
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Title: Susceptibility of cattle to the agent of chronic wasting disease
from elk after intracranial inoculation
Authors
item Greenlee, Justin item Nicholson, Eric item Smith, Jodi item Kunkle,
Robert item Hamir, Amirali
Submitted to: Journal of Veterinary Diagnostic Investigation Publication
Type: Peer Reviewed Journal Publication Acceptance
Date: July 12, 2012
Publication Date: November 1, 2012
Citation: Greenlee, J.J., Nicholson, E.M., Smith, J.D., Kunkle, R.A.,
Hamir, A.N. 2012.
Susceptibility of cattle to the agent of chronic wasting disease from elk
after intracranial inoculation.
Journal of Veterinary Diagnostic Investigation. 24(6):1087-1093.
Interpretive Summary: Chronic Wasting Disease (CWD), a fatal
neurodegenerative disease that occurs in farmed and wild cervids (deer and elk)
of North America, is a transmissible spongiform encephalopathy (TSE). TSEs are
caused by infectious proteins called prions that are resistant to various
methods of decontamination and environmental degradation. Cattle could be
exposed to chronic wasting disease (CWD) by contact with infected farmed or
free-ranging cervids. The purpose of this study was to assess the potential
transmission of CWD from elk to cattle after intracranial inoculation, the most
direct route to test the potential of a host to replicate an isolate of the
prion agent. This study reports that only 2 of 14 calves inoculated with CWD
from elk had clinical signs or evidence of abnormal prion protein accumulation.
These results suggest that cattle are unlikely to be susceptible to CWD if
inoculated by a more natural route. This information could have an impact on
regulatory officials developing plans to reduce or eliminate TSEs and farmers
with concerns about ranging cattle on areas where CWD may be present.
Technical Abstract:
***Cattle could be exposed to the agent of chronic wasting disease (CWD)
through contact with infected farmed or free-ranging cervids or exposure to
contaminated premises. The purpose of this study was to assess the potential for
CWD derived from elk to transmit to cattle after intracranial inoculation.
Calves (n=14) were inoculated with brain homogenate derived from elk with CWD to
determine the potential for transmission and define the clinicopathologic
features of disease.
Cattle were necropsied if clinical signs occurred or at the termination of
experiment (49 months post-inoculation (MPI)).
Clinical signs of poor appetite, weight loss, circling, and bruxism
occurred in two cattle (14%) at 16 and 17 MPI, respectively.
Accumulation of abnormal prion protein (PrP**Sc) in these cattle was
confined to the central nervous system with the most prominent immunoreactivity
in midbrain, brainstem, and hippocampus with lesser immunoreactivity in the
cervical spinal cord.
*** The rate of transmission was lower than in cattle inoculated with CWD
derived from mule deer (38%) or white-tailed deer (86%).
Additional studies are required to fully assess the potential for cattle to
develop CWD through a more natural route of exposure, but a low rate of
transmission after intracranial inoculation suggests that risk of transmission
through other routes is low.
***A critical finding here is that if CWD did transmit to exposed cattle,
currently used diagnostic techniques would detect and differentiate it from
other prion diseases in cattle based on absence of spongiform change, distinct
pattern of PrP**Sc deposition, and unique molecular profile.
*** P.126: Successful transmission of chronic wasting disease (CWD) into
mice over-expressing bovine prion protein (TgSB3985) ***
Larisa Cervenakova,1 Christina J Sigurdson,2 Pedro Piccardo,3 Oksana
Yakovleva,1 Irina Vasilyeva,1 Jorge de Castro,1 Paula Saá,1 and Anton Cervenak1
1American Red Cross, Holland Laboratory; Rockville, MD USA; 2University of
California; San Diego, CA USA; 3Lab TSE/OBRR /CBER/FDA; Rockville, MD USA
Keywords: chronic wasting disease, transmission, transgenic mouse, bovine
prion protein
Background. CWD is a disease affecting wild and farmraised cervids in North
America. Epidemiological studies provide no evidence of CWD transmission to
humans. Multiple attempts have failed to infect transgenic mice expressing human
PRNP gene with CWD. The extremely low efficiency of PrPCWD to convert normal
human PrPC in vitro provides additional evidence that transmission of CWD to
humans cannot be easily achieved. However, a concern about the risk of CWD
transmission to humans still exists. This study aimed to establish and
characterize an experimental model of CWD in TgSB3985 mice with the following
attempt of transmission to TgHu mice.
Materials and Methods. TgSB3985 mice and wild-type FVB/ NCrl mice were
intracranially injected with 1% brain homogenate from a CWD-infected Tga20 mouse
(CWD/Tga20). TgSB3985 and TgRM (over-expressing human PrP) were similarly
injected with 5% brain homogenates from CWD-infected white-tailed deer (CWD/WTD)
or elk (CWD/Elk). Animals were observed for clinical signs of neurological
disease and were euthanized when moribund. Brains and spleens were removed from
all mice for PrPCWD detection by Western blotting (WB). A histological analysis
of brains from selected animals was performed: brains were scored for the
severity of spongiform change, astrogliosis, and PrPCWD deposition in ten brain
regions.
Results. Clinical presentation was consistent with TSE. More than 90% of
TgSB3985 and wild-type mice infected with CWD/Tga20, tested positive for PrPres
in the brain but only mice in the latter group carried PrPCWD in their spleens.
We found evidence for co-existence or divergence of two CWD/ Tga20 strains based
on biochemical and histological profiles. In TgSB3985 mice infected with CWD-elk
or CWD-WTD, no animals tested positive for PrPCWD in the brain or in the spleen
by WB. However, on neuropathological examination we found presence of amyloid
plaques that stained positive for PrPCWD in three CWD/WTD- and two
CWD/Elk-infected TgSB3985 mice. The neuropathologic profiles in CWD/WTD- and
CWD/Elkinfected mice were similar but unique as compared to profiles of BSE,
BSE-H or CWD/Tg20 agents propagated in TgSB3985 mice. None of CWD-infected TgRM
mice tested positive for PrPCWD by WB or by immunohistochemical detection.
Conclusions. To our knowledge, this is the first established experimental
model of CWD in TgSB3985. We found evidence for co-existence or divergence of
two CWD strains adapted to Tga20 mice and their replication in TgSB3985 mice.
Finally, we observed phenotypic differences between cervid-derived CWD and
CWD/Tg20 strains upon propagation in TgSB3985 mice. Further studies are underway
to characterize these strains.
TSS
UPDATED CORRESPONDENCE FROM AUTHORS OF THIS STUDY I.E. COLBY, PRUSINER ET
AL, ABOUT MY CONCERNS OF THE DISCREPANCY BETWEEN THEIR FIGURES AND MY FIGURES OF
THE STUDIES ON CWD TRANSMISSION TO CATTLE ;
CWD to cattle figures CORRECTION
Greetings,
I believe the statement and quote below is incorrect ;
"CWD has been transmitted to cattle after intracerebral inoculation,
although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This
finding raised concerns that CWD prions might be transmitted to cattle grazing
in contaminated pastures."
Please see ;
Within 26 months post inoculation, 12 inoculated animals had lost weight,
revealed abnormal clinical signs, and were euthanatized. Laboratory tests
revealed the presence of a unique pattern of the disease agent in tissues of
these animals. These findings demonstrate that when CWD is directly inoculated
into the brain of cattle, 86% of inoculated cattle develop clinical signs of the
disease.
" although the infection rate was low (4 of 13 animals [Hamir et al.
2001]). "
shouldn't this be corrected, 86% is NOT a low rate. ...
kindest regards,
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
Thank you!
Thanks so much for your updates/comments. We intend to publish as rapidly
as possible all updates/comments that contribute substantially to the topic
under discussion.
re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 + Author
Affiliations
1Institute for Neurodegenerative Diseases, University of California, San
Francisco, San Francisco, California 94143 2Department of Neurology, University
of California, San Francisco, San Francisco, California 94143 Correspondence:
stanley@ind.ucsf.edu
Mule deer, white-tailed deer, and elk have been reported to develop CWD. As
the only prion disease identified in free-ranging animals, CWD appears to be far
more communicable than other forms of prion disease. CWD was first described in
1967 and was reported to be a spongiform encephalopathy in 1978 on the basis of
histopathology of the brain. Originally detected in the American West, CWD has
spread across much of North America and has been reported also in South Korea.
In captive populations, up to 90% of mule deer have been reported to be positive
for prions (Williams and Young 1980). The incidence of CWD in cervids living in
the wild has been estimated to be as high as 15% (Miller et al. 2000). The
development of transgenic (Tg) mice expressing cervid PrP, and thus susceptible
to CWD, has enhanced detection of CWD and the estimation of prion titers
(Browning et al. 2004; Tamgüney et al. 2006). Shedding of prions in the feces,
even in presymptomatic deer, has been identified as a likely source of infection
for these grazing animals (Williams and Miller 2002; Tamgüney et al. 2009b). CWD
has been transmitted to cattle after intracerebral inoculation, although the
infection rate was low (4 of 13 animals [Hamir et al. 2001]). This finding
raised concerns that CWD prions might be transmitted to cattle grazing in
contaminated pastures.
snip...
----- Original Message -----
From: David Colby To: flounder9@verizon.net
Cc: stanley@XXXXXXXX
Sent: Tuesday, March 01, 2011 8:25 AM
Subject: Re: FW: re-Prions David W. Colby1,* and Stanley B. Prusiner1,2 +
Author Affiliations
Dear Terry Singeltary,
Thank you for your correspondence regarding the review article Stanley
Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner
asked that I reply to your message due to his busy schedule. We agree that the
transmission of CWD prions to beef livestock would be a troubling development
and assessing that risk is important. In our article, we cite a peer-reviewed
publication reporting confirmed cases of laboratory transmission based on
stringent criteria. The less stringent criteria for transmission described in
the abstract you refer to lead to the discrepancy between your numbers and ours
and thus the interpretation of the transmission rate. We stand by our assessment
of the literature--namely that the transmission rate of CWD to bovines appears
relatively low, but we recognize that even a low transmission rate could have
important implications for public health and we thank you for bringing attention
to this matter. Warm Regards, David Colby -- David Colby, PhDAssistant Professor
Department of Chemical Engineering University of Delaware
===========END...TSS==============
SNIP...SEE FULL TEXT ;
Friday, August 14, 2015
*** Susceptibility of cattle to the agent of chronic wasting disease from
elk after intracranial inoculation ***
Friday, May 27, 2016 Canine Prions: A New Form of Prion Disease EP-021
PRION 2016 TOKYO EP-021 Canine Prions: A New Form of Prion Disease
Mourad Tayebi1, Monique A David2, Brian Summers3
1 University of Melbourne, Veterinary Sciences, Australia; 2Ausbiologics,
Sydney, Australia; 3Royal Veterinary College, London, UK
The origin of bovine spongiform encephalopathy (BSE), which rapidly evolved
into a major epidemic remains unresolved and was initially widely attributed to
transmission of sheep scrapie to cattle with contaminated feed prepared from
rendered sheep carcasses. Alternative transmission hypotheses also include feed
contaminated with unrecognized subclinical case(s) of bovine prion disease or
with prion-infected human remains. However, following the demonstration of a BSE
case exhibiting the novel mutation E211 K, similar to the E200K mutation
associated with most genetic CJD in humans, support for a genetic origin of
prion disease in cattle is gaining momentum. In contrast to other animal species
such as feline, the canine species seems to be resistant to prion disease as no
canine prion cases were previously reported.
We describe here three cases of Rottweiler puppy (called RWD cases) with
neurological deficits and spongiform change. We used animal bioassays and in
vitro studies to show efficient interspecies transmission of this novel canidae
prion isolate to other species.
Biochemical studies revealed the presence of partially proteinase K
(PK)-resistant fragment and immunohistochemistry displayed staining for PrPSc in
the cerebral cortex. Importantly, interspecies transmission of canine PrPSc
derived from RWD3 brain homogenates following inoculation of hamsters led to
signs of prion disease and replication of PrPSc in brains, spinal cords and
spleens of these animals.
These findings if confirmed by further cases of prion disease in canidae
and regardless of the origin of the disease would have a major impact on animal
and public health.
PRION 2016 TOKYO
Friday, May 27, 2016 Canine Prions: A New Form of Prion Disease EP-021
PRION 2016 TOKYO
EP-021 Canine Prions: A New Form of Prion Disease
*** DEFRA TO SINGELTARY ON HOUND STUDY AND BSE 2001 ***
DEFRA Department for Environment, Food & Rural Affairs
Area 307, London, SW1P 4PQ Telephone: 0207 904 6000 Direct line: 0207 904
6287 E-mail: h.mcdonagh.defra.gsi.gov.uk
GTN: FAX:
Mr T S Singeltary P.O. Box 42 Bacliff Texas USA 77518
21 November 2001
Dear Mr Singeltary
TSE IN HOUNDS
Thank you for e-mail regarding the hounds survey. I am sorry for the long
delay in responding.
As you note, the hound survey remains unpublished. However the Spongiform
Encephalopathy Advisory Committee (SEAC), the UK Government's independent
Advisory Committee on all aspects related to BSE-like disease, gave the hound
study detailed consideration at their meeting in January 1994. As a summary of
this meeting published in the BSE inquiry noted, the Committee were clearly
concerned about the work that had been carried out, concluding that there had
clearly been problems with it, particularly the control on the histology, and
that it was more or less inconclusive. However was agreed that there should be a
re-evaluation of the pathological material in the study.
Later, at their meeting in June 95, The Committee re-evaluated the hound
study to see if any useful results could be gained from it. The Chairman
concluded that there were varying opinions within the Committee on further work.
It did not suggest any further transmission studies and thought that the lack of
clinical data was a major weakness.
Overall, it is clear that SEAC had major concerns about the survey as
conducted. As a result it is likely that the authors felt that it would not
stand up to r~eer review and hence it was never published. As noted above, and
in the detailed minutes of the SEAC meeting in June 95, SEAC considered whether
additional work should be performed to examine dogs for evidence of TSE
infection. Although the Committee had mixed views about the merits of conducting
further work, the Chairman noted that when the Southwood Committee made their
recommendation to complete an assessment of possible spongiform disease in dogs,
no TSEs had been identified in other species and hence dogs were perceived as a
high risk population and worthy of study. However subsequent to the original
recommendation, made in 1990, a number of other species had been identified with
TSE ( e.g. cats) so a study in hounds was less critical. For more details see-
http://www.bseinquiry.gov.uk/files/yb/1995/06/21005001.pdf
As this study remains unpublished, my understanding is that the ownership
of the data essentially remains with the original researchers. Thus
unfortunately, I am unable to help with your request to supply information on
the hound survey directly. My only suggestion is that you contact one of the
researchers originally involved in the project, such as Gerald Wells. He can be
contacted at the following address.
Dr Gerald Wells, Veterinary Laboratories Agency, New Haw, Addlestone,
Surrey, KT 15 3NB, UK
You may also wish to be aware that since November 1994 all suspected cases
of spongiform encephalopathy in animals and poultry were made notifiable. Hence
since that date there has been a requirement for vets to report any suspect SE
in dogs for further investigation. To date there has never been positive
identification of a TSE in a dog.
I hope this is helpful
Yours sincerely 4
HUGH MCDONAGH BSE CORRESPONDENCE SECTION
======================================
HOUND SURVEY
I am sorry, but I really could have been a co-signatory of Gerald's minute.
I do NOT think that we can justify devoting any resources to this study,
especially as larger and more important projects such as the pathogenesis study
will be quite demanding.
If there is a POLITICAL need to continue with the examination of hound
brains then it should be passed entirely to the VI Service.
J W WILESMITH Epidemiology Unit 18 October 1991
Mr. R Bradley
cc: Mr. G A H Wells
3.3. Mr R J Higgins in conjunction with Mr G A Wells and Mr A C Scott would
by the end of the year, indentify the three brains that were from the
''POSITIVE'' end of the lesion spectrum.
TSE in dogs have not been documented simply because OF THE ONLY STUDY,
those brain tissue samples were screwed up too. see my investigation of this
here, and to follow, later follow up, a letter from defra, AND SEE SUSPICIOUS
BRAIN TISSUE SAF's. ...TSS
TSE & HOUNDS
GAH WELLS (very important statement here...TSS)
HOUND STUDY
AS implied in the Inset 25 we must not _ASSUME_ that transmission of BSE to
other species will invariably present pathology typical of a scrapie-like
disease.
snip...
76 pages on hound study;
snip...
The spongiform changes were not pathognomonic (ie. conclusive proof) for
prion disease, as they were atypical, being largely present in white matter
rather than grey matter in the brain and spinal cord. However, Tony Scott, then
head of electron microscopy work on TSEs, had no doubt that these SAFs were
genuine and that these hounds therefore must have had a scrapie-like disease. I
reviewed all the sections myself (original notes appended) and although the
pathology was not typical, I could not exclude the possibility that this was a
scrapie-like disorder, as white matter vacuolation is seen in TSEs and Wallerian
degeneration was also present in the white matter of the hounds, another feature
of scrapie.
38.I reviewed the literature on hound neuropathology, and discovered that
micrographs and descriptive neuropathology from papers on 'hound ataxia'
mirrored those in material from Robert Higgins' hound survey. Dr Tony Palmer
(Cambridge) had done much of this work, and I obtained original sections from
hound ataxia cases from him. This enabled me provisionally to conclude that
Robert Higgins had in all probability detected hound ataxia, but also that hound
ataxia itself was possibly a TSE. Gerald Wells confirmed in 'blind' examination
of single restricted microscopic fields that there was no distinction between
the white matter vacuolation present in BSE and scrapie cases, and that
occurring in hound ataxia and the hound survey cases.
39.Hound ataxia had reportedly been occurring since the 1930's, and a known
risk factor for its development was the feeding to hounds of downer cows, and
particularly bovine offal. Circumstantial evidence suggests that bovine offal
may also be causal in FSE, and TME in mink. Despite the inconclusive nature of
the neuropathology, it was clearly evident that this putative canine spongiform
encephalopathy merited further investigation.
40.The inconclusive results in hounds were never confirmed, nor was the
link with hound ataxia pursued. I telephoned Robert Higgins six years after he
first sent the slides to CVL. I was informed that despite his submitting a
yearly report to the CVO including the suggestion that the hound work be
continued, no further work had been done since 1991. This was surprising, to say
the very least.
41.The hound work could have provided valuable evidence that a scrapie-like
agent may have been present in cattle offal long before the BSE epidemic was
recognised. The MAFF hound survey remains unpublished.
Histopathological support to various other published MAFF experiments
42.These included neuropathological examination of material from
experiments studying the attempted transmission of BSE to chickens and pigs (CVL
1991) and to mice (RVC 1994).
It was thought likely that at least some, and probably all, of the cases in
zoo animals were caused by the BSE agent. Strong support for this hypothesis
came from the findings of Bruce and others (1994) ( Bruce, M.E., Chree, A.,
McConnell, I., Foster, J., Pearson, G. & Fraser, H. (1994) Transmission of
bovine spongiform encephalopathy and scrapie to mice: strain variation and
species barrier. Philosophical Transactions of the Royal Society B 343, 405-411:
J/PTRSL/343/405 ), who demonstrated that the pattern of variation in incubation
period and lesion profile in six strains of mice inoculated with brain
homogenates from an affected kudu and the nyala, was similar to that seen when
this panel of mouse strains was inoculated with brain from cattle with BSE. The
affected zoo bovids were all from herds that were exposed to feeds that were
likely to have contained contaminated ruminant-derived protein and the zoo
felids had been exposed, if only occasionally in some cases, to tissues from
cattle unfit for human consumption.
snip...
NEW URL ;
Assessing Transmissible Spongiform Encephalopathy Species Barriers with an
In Vitro Prion Protein Conversion Assay
Christopher J. Johnson1, Christina M. Carlson2, Aaron R. Morawski3, Alyson
Manthei4, Neil R. Cashman5
1USGS National Wildlife Health Center, 2Department of Soil Science,
University of Wisconsin–Madison, 3Laboratory of Immunology, National Institute
of Allergy and Infectious Diseases, National Institutes of Health, 4Merial
Veterinary Scholars Program, School of Veterinary Medicine, University of
Wisconsin–Madison, 5Department of Neurology, University of British Columbia
Summary
Measuring the barrier to the interspecies transmission of prion diseases is
challenging and typically involves animal challenges or biochemical assays.
Here, we present an in vitro prion protein conversion assay with the ability to
predict species barriers.
Date Published: 3/10/2015, Issue 97; doi: 10.3791/52522
Keywords: Medicine, Issue 97, Prion, species barrier, conversion,
immunoblotting, transmissible spongiform encephalopathy, interspecies
transmission Cite this Article
Johnson, C. J., Carlson, C. M., Morawski, A. R., Manthei, A., Cashman, N.
R. Assessing Transmissible Spongiform Encephalopathy Species Barriers with an In
Vitro Prion Protein Conversion Assay. J. Vis. Exp. (97), e52522,
doi:10.3791/52522 (2015). Abstract
Studies to understanding interspecies transmission of transmissible
spongiform encephalopathies (TSEs, prion diseases) are challenging in that they
typically rely upon lengthy and costly in vivo animal challenge studies. A
number of in vitro assays have been developed to aid in measuring prion species
barriers, thereby reducing animal use and providing quicker results than animal
bioassays. Here, we present the protocol for a rapid in vitro prion conversion
assay called the conversion efficiency ratio (CER) assay. In this assay cellular
prion protein (PrPC) from an uninfected host brain is denatured at both pH 7.4
and 3.5 to produce two substrates. When the pH 7.4 substrate is incubated with
TSE agent, the amount of PrPC that converts to a proteinase K (PK)-resistant
state is modulated by the original host’s species barrier to the TSE agent. In
contrast, PrPC in the pH 3.5 substrate is misfolded by any TSE agent. By
comparing the amount of PK-resistant prion protein in the two substrates, an
assessment of the host’s species barrier can be made. We show that the CER assay
correctly predicts known prion species barriers of laboratory mice and, as an
example, show some preliminary results suggesting that bobcats (Lynx rufus) may
be susceptible to white-tailed deer (Odocoileus virginianus) chronic wasting
disease agent.
>>> show some preliminary results suggesting that bobcats (Lynx
rufus) may be susceptible to white-tailed deer (Odocoileus virginianus) chronic
wasting disease agent.
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.
www.landesbioscience.com
PO-081: Chronic wasting disease in the cat— Similarities to feline
spongiform encephalopathy (FSE)
PO-081: Chronic wasting disease in the cat— Similarities to feline
spongiform encephalopathy (FSE)
Thursday, May 31, 2012
CHRONIC WASTING DISEASE CWD PRION2012 Aerosol, Inhalation transmission,
Scrapie, cats, species barrier, burial, and more
Monday, August 8, 2011
Susceptibility of Domestic Cats to CWD Infection
Sunday, August 25, 2013
Prion2013 Chronic Wasting Disease CWD risk factors, humans, domestic cats,
blood, and mother to offspring transmission
Feline Spongiform Encephalopathy (FSE) FSE was first identified in the UK
in 1990. Most cases have been reported in the UK, where the epidemic has been
consistent with that of the BSE epidemic. Some other countries (e.g. Norway,
Liechtenstein and France) have also reported cases.
Most cases have been reported in domestic cats but there have also been
cases in captive exotic cats (e.g. Cheetah, Lion, Asian leopard cat, Ocelot,
Puma and Tiger). The disease is characterised by progressive nervous signs,
including ataxia, hyper-reactivity and behavioural changes and is fatal.
The chemical and biological properties of the infectious agent are
identical to those of the BSE and vCJD agents. These findings support the
hypothesis that the FSE epidemic resulted from the consumption of food
contaminated with the BSE agent.
The FSE epidemic has declined as a result of tight controls on the disposal
of specified risk material and other animal by-products.
References: Leggett, M.M. et al.(1990) A spongiform encephalopathy in a
cat. Veterinary Record. 127. 586-588
Synge, B.A. et al. (1991) Spongiform encephalopathy in a Scottish cat.
Veterinary Record. 129. 320
Wyatt, J. M. et al. (1991) Naturally occurring scrapie-like spongiform
encephalopathy in five domestic cats. Veterinary Record. 129. 233.
Gruffydd-Jones, T. J.et al.. (1991) Feline spongiform encephalopathy. J.
Small Animal Practice. 33. 471-476.
Pearson, G. R. et al. (1992) Feline spongiform encephalopathy: fibril and
PrP studies. Veterinary Record. 131. 307-310.
Willoughby, K. et al. (1992) Spongiform encephalopathy in a captive puma
(Felis concolor). Veterinary Record. 131. 431-434.
Fraser, H. et al. (1994) Transmission of feline spongiform encephalopathy
to mice. Veterinary Record 134. 449.
Bratberg, B. et al. (1995) Feline spongiform encephalopathy in a cat in
Norway. Veterinary Record 136. 444
Baron, T. et al. (1997) Spongiform encephalopathy in an imported cheetah in
France. Veterinary Record 141. 270-271
Zanusso, G et al. (1998) Simultaneous occurrence of spongiform
encephalopathy in a man and his cat in Italy. Lancet, V352, N9134, OCT 3, Pp
1116-1117.
Ryder, S.J. et al. (2001) Inconsistent detection of PrP in extraneural
tissues of cats with feline spongiform encephalopathy. Veterinary Record 146.
437-441
Kelly, D.F. et al. (2005) Neuropathological findings in cats with
clinically suspect but histologically unconfirmed feline spongiform
encephalopathy. Veterinary Record 156. 472-477.
3 further cheetah cases have occured, plus 1 lion, plus all the primates,
and 20 additional house cats. Nothing has been published on any of these UK
cases either. One supposes the problem here with publishing is that many
unpublished cases were _born_ long after the feed "ban". Caught between a rock
and a hard place: leaky ban or horizontal transmission (or both).
YOU explained that imported crushed heads were extensively used in the
petfood industry...
http://web.archive.org/web/20060303042720/http://www.bseinquiry.gov.uk/files/yb/1989/04/14001001.pdf
In particular I do not believe one can say that the levels of the scrapie
agent in pet food are so low that domestic animals are not exposed...
http://web.archive.org/web/20040301231838/http://www.bseinquiry.gov.uk/files/yb/1989/04/24003001.pdf
http://web.archive.org/web/20060303042732/http://www.bseinquiry.gov.uk/files/yb/1989/04/25001001.pdf
on occassions, materials obtained from slaughterhouses will be derived from
sheep affected with scrapie or cattle that may be incubating BSE for use in
petfood manufacture...
http://web.archive.org/web/20060303042739/http://www.bseinquiry.gov.uk/files/yb/1989/05/03007001.pdf
*** Meldrum's notes on pet foods and materials used
http://web.archive.org/web/20060303042745/http://www.bseinquiry.gov.uk/files/yb/1989/05/16001001.pdf
*** BSE & Pedigree Petfoods ***
http://web.archive.org/web/20060303042725/http://www.bseinquiry.gov.uk/files/yb/1989/05/16002001.pdf
In 2003, Denver Post reporter Theo Stein interviewed scientists about CWD
spreading though deer and elk in Colorado. Dr. Valerius Geist, who paradoxically
has become a darling of anti-wolfers, made this assertion about the significance
of wolves in containing CWD spread via proteins called prions.
“Wolves will certainly bring the disease to a halt,” he said. “They will
remove infected individuals and clean up carcasses that could transmit the
disease.”
Stein added that “Geist and Princeton University biologist Andrew Dobson
theorize that killing off the wolf allowed CWD to take hold in the first
place.”
Wolves aren’t alone. In a 2009 study titled “Mountain lions prey
selectively on prion-infected mule deer,” researchers in Colorado discovered
that “adult mule deer killed by mountain lions were more likely to be
prion-infected than were deer killed more randomly … suggesting that mountain
lions were selecting for infected individuals when they targeted adult
deer.”
NO, NO, NOT NO, BUT HELL KNOW !!!
PLEASE be careful what you ask for.
recently, canine spongiform encephalopathy has been confirmed.
I proved this in 2005, with a letter from MAFF/DEFRA et al confirming my
suspicions of the ‘hound study’ way back. this was covered up. see documents
below.
also, recently, cwd to the domestic cat is a great concern.
even though to date, as far as I am aware of, the cwd study on the mountain
lion has not produced any confirmation yet, we already know that the feline
species is highly succeptible to the TSE prion. domestic cats and the exotic zoo
big cats.
so in my honest opinion, any program that would use wild animals to prey on
other wild animals, as a tool to help curb CWD TSE prion disease, would only
help enhance the spread of disease, and it would only help spread the disease to
other species. ...TSS
Monday, February 14, 2011
THE ROLE OF PREDATION IN DISEASE CONTROL: A COMPARISON OF SELECTIVE AND
NONSELECTIVE REMOVAL ON PRION DISEASE DYNAMICS IN DEER
NO, NO, NOT NO, BUT HELL NO !
Journal of Wildlife Diseases, 47(1), 2011, pp. 78-93 © Wildlife Disease
Association 2011
OR-09: Canine spongiform encephalopathy—A new form of animal prion disease
Monique David, Mourad Tayebi UT Health; Houston, TX USA
It was also hypothesized that BSE might have originated from an
unrecognized sporadic or genetic case of bovine prion disease incorporated into
cattle feed or even cattle feed contaminated with prion-infected human remains.1
However, strong support for a genetic origin of BSE has recently been
demonstrated in an H-type BSE case exhibiting the novel mutation E211K.2
Furthermore, a specific prion protein strain causing BSE in cattle is believed
to be the etiological agent responsible for the novel human prion disease,
variant Creutzfeldt-Jakob disease (vCJD).3 Cases of vCJD have been identified in
a number countries, including France, Italy, Ireland, the Netherlands, Canada,
Japan, US and the UK with the largest number of cases. Naturally occurring
feline spongiform encephalopathy of domestic cats4 and spongiform
encephalopathies of a number of zoo animals so-called exotic ungulate
encephalopathies5,6 are also recognized as animal prion diseases, and are
thought to have resulted from the same BSE-contaminated food given to cattle and
humans, although and at least in some of these cases, a sporadic and/or genetic
etiology cannot be ruled out. The canine species seems to display resistance to
prion disease and no single case has so far been reported.7,8 Here, we describe
a case of a 9 week old male Rottweiler puppy presenting neurological deficits;
and histological examination revealed spongiform vacuolation characteristic of
those associated with prion diseases.9 Initial biochemical studies using
anti-PrP antibodies revealed the presence of partially proteinase K-resistant
fragment by western blotting. Furthermore, immunohistochemistry revealed
spongiform degeneration consistent with those found in prion disease and
displayed staining for PrPSc in the cortex.
Of major importance, PrPSc isolated from the Rottweiler was able to cross
the species barrier transmitted to hamster in vitro with PMCA and in vivo (one
hamster out of 5). Futhermore, second in vivo passage to hamsters, led to 100%
attack rate (n = 4) and animals displayed untypical lesional profile and shorter
incubation period.
In this study, we show that the canine species might be sensitive to prion
disease and that PrPSc isolated from a dog can be transmitted to dogs and
hamsters in vitro using PMCA and in vivo to hamsters.
If our preliminary results are confirmed, the proposal will have a major
impact on animal and public health and would certainly lead to implementing new
control measures for ‘canine spongiform encephalopathy’ (CSE).
References 1. Colchester AC, Colchester NT. The origin of bovine spongiform
encephalopathy: the human prion disease hypothesis. Lancet 2005; 366:856-61;
PMID:16139661; http://
dx.doi.org/10.1016/S0140-6736(05)67218-2.
2. Richt JA, Hall SM. BSE case associated with prion protein gene mutation.
PLoS Pathog 2008; 4:e1000156; PMID:18787697; http://dx.doi.org/10.1371/journal.
ppat.1000156.
3. Collinge J. Human prion diseases and bovine spongiform encephalopathy
(BSE). Hum Mol Genet 1997; 6:1699-705; PMID:9300662; http://dx.doi.org/10.1093/
hmg/6.10.1699.
4. Wyatt JM, Pearson GR, Smerdon TN, Gruffydd-Jones TJ, Wells GA, Wilesmith
JW. Naturally occurring scrapie-like spongiform encephalopathy in five domestic
cats. Vet Rec 1991; 129:233-6; PMID:1957458; http://dx.doi.org/10.1136/vr.129.11.233.
5. Jeffrey M, Wells GA. Spongiform encephalopathy in a nyala (Tragelaphus
angasi). Vet Pathol 1988; 25:398-9; PMID:3232315; http://dx.doi.org/10.1177/030098588802500514.
6. Kirkwood JK, Wells GA, Wilesmith JW, Cunningham AA, Jackson SI.
Spongiform encephalopathy in an arabian oryx (Oryx leucoryx) and a greater kudu
(Tragelaphus strepsiceros). Vet Rec 1990; 127:418-20; PMID:2264242.
7. Bartz JC, McKenzie DI, Bessen RA, Marsh RF, Aiken JM. Transmissible mink
encephalopathy species barrier effect between ferret and mink: PrP gene and
protein analysis. J Gen Virol 1994; 75:2947-53; PMID:7964604; http://dx.doi.org/10.1099/0022-1317-
75-11-2947.
8. Lysek DA, Schorn C, Nivon LG, Esteve-Moya V, Christen B, Calzolai L, et
al. Prion protein NMR structures of cats, dogs, pigs, and sheep. Proc Natl Acad
Sci U S A 2005; 102:640-5; PMID:15647367; http://dx.doi.org/10.1073/pnas.0408937102.
9. Budka H. Neuropathology of prion diseases. Br Med Bull 2003; 66:121-30;
PMID:14522854; http://dx.doi.org/10.1093/bmb/66.1.121.
Monday, March 26, 2012
CANINE SPONGIFORM ENCEPHALOPATHY: A NEW FORM OF ANIMAL PRION DISEASE
http://caninespongiformencephalopathy.blogspot.com/2012/03/canine-spongiform-encephalopathy-new.html
Monday, March 8, 2010
Canine Spongiform Encephalopathy aka MAD DOG DISEASE
Chronic Wasting Disease Susceptibility of Four North American Rodents
Chad J. Johnson1*, Jay R. Schneider2, Christopher J. Johnson2, Natalie A.
Mickelsen2, Julia A. Langenberg3, Philip N. Bochsler4, Delwyn P. Keane4, Daniel
J. Barr4, and Dennis M. Heisey2 1University of Wisconsin School of Veterinary
Medicine, Department of Comparative Biosciences, 1656 Linden Drive, Madison WI
53706, USA 2US Geological Survey, National Wildlife Health Center, 6006
Schroeder Road, Madison WI 53711, USA 3Wisconsin Department of Natural
Resources, 101 South Webster Street, Madison WI 53703, USA 4Wisconsin Veterinary
Diagnostic Lab, 445 Easterday Lane, Madison WI 53706, USA *Corresponding author
email: cjohnson@svm.vetmed.wisc.edu
We intracerebrally challenged four species of native North American rodents
that inhabit locations undergoing cervid chronic wasting disease (CWD)
epidemics. The species were: deer mice (Peromyscus maniculatus), white-footed
mice (P. leucopus), meadow voles (Microtus pennsylvanicus), and red-backed voles
(Myodes gapperi). The inocula were prepared from the brains of hunter-harvested
white-tailed deer from Wisconsin that tested positive for CWD. Meadow voles
proved to be most susceptible, with a median incubation period of 272 days.
Immunoblotting and immunohistochemistry confirmed the presence of PrPd in the
brains of all challenged meadow voles. Subsequent passages in meadow voles lead
to a significant reduction in incubation period. The disease progression in
red-backed voles, which are very closely related to the European bank vole (M.
glareolus) which have been demonstrated to be sensitive to a number of TSEs, was
slower than in meadow voles with a median incubation period of 351 days. We
sequenced the meadow vole and red-backed vole Prnp genes and found three amino
acid (AA) differences outside of the signal and GPI anchor sequences. Of these
differences (T56-, G90S, S170N; read-backed vole:meadow vole), S170N is
particularly intriguing due its postulated involvement in "rigid loop" structure
and CWD susceptibility. Deer mice did not exhibit disease signs until nearly 1.5
years post-inoculation, but appear to be exhibiting a high degree of disease
penetrance. White-footed mice have an even longer incubation period but are also
showing high penetrance. Second passage experiments show significant shortening
of incubation periods. Meadow voles in particular appear to be interesting lab
models for CWD. These rodents scavenge carrion, and are an important food source
for many predator species. Furthermore, these rodents enter human and domestic
livestock food chains by accidental inclusion in grain and forage. Further
investigation of these species as potential hosts, bridge species, and
reservoirs of CWD is required.
please see ;
Subject: Re: TEXAS CONFIRMATION OF BOVINE SPONGIFORM ENCEPHALOPATHY BSE TSE
PRION IN ONE SAMPLE OF SORGHUM DDGS OUT OF 168 DG SAMPLES
***UPDATED CORRECTION BY AUTHOR...SEE EMAIL TO ME...terry
From: Kyung-Min Lee Sent: Thursday, October 01, 2015 1:39 PM
To: Terry S. Singeltary Sr. ; BSE-L@LISTS.AEGEE.ORG
Cc: CJD-L@LISTS.AEGEE.ORG ; cjdvoice@yahoogroups.com ;
bloodcjd@yahoogroups.com ; jcattanach@foodprotection.org ; cnc3@psu.edu ;
dloynachan@foodprotection.org ; lhovey@foodprotection.org ; Timothy J. Herrman
Subject: RE: TEXAS CONFIRMATION OF BOVINE SPONGIFORM ENCEPHALOPATHY BSE TSE
PRION IN ONE SAMPLE OF SORGHUM DDGS OUT OF 168 DG SAMPLES
Dear Terry S. Singeltary Sr.
Thank for your interest and concern about our published article entitled
“Evaluation of Selected Nutrients and Contaminants in Distillers Grains from
Ethanol Production in Texas”. I should apologize you and others that there were
some errors and misleading statements in this article due to inappropriate
terminology. The statement you were concerned about was corrected to "One
sorghum DDGS out of 168 DG samples was contaminated with animal protein
prohibited for use in ruminant feed and was channeled to poultry feed." We
requested the journal editor to correct some errors and the relevant statements,
or to withdraw the article from the journal.
Again I sincerely apologize for any confusion and inconvenience this may
cause. Thanks.
best wishes,
Kyung-Min
Kyung-Min Lee, Ph. D. Research Scientist Office of the Texas State
Chemist
Texas A&M AgriLife Research P.O. Box 3160, College Station, TX
77841-3160 Phone: 979-845-4113 (ext 132) Email:kml@otsc.tamu.edu Fax:
979-845-1389
snip...end...tss
my link corrected
Sunday, September 27, 2015
TEXAS CONFIRMATION OF BOVINE SPONGIFORM ENCEPHALOPATHY BSE TSE PRION IN ONE
SAMPLE OF SORGHUM DDGS OUT OF 168 DG SAMPLES
A CONTRIBUTION TO THE NEUROPATHOLOGY OF THE RED-NECKED OSTRICH (STRUTHIO
CAMELUS) - SPONGIFORM ENCEPHALOPATHY
4.21 Three cases of SE’s with an unknown infectious agent have been
reported in ostriches (Struthio Camellus) in two zoos in north west Germany
(Schoon @ Brunckhorst, 1999, Verh ber Erkeg Zootiere 33:309-314). These birds
showed protracted central nervous symptoms with ataxia, disturbances of balance
and uncoordinated feeding behaviour. The diet of these birds had included
poultry meat meal, some of which came from cattle emergency slaughter cases.
SE1806
TRANSMISSION STUDIES OF BSE TO DOMESTIC FOWL BY ORAL EXPOSURE TO BRAIN
HOMOGENATE
1 challenged cock bird was necropsied (41 months p.i.) following a period
of ataxia, tremor, limb abduction and other neurological signs.
Histopathological examination failed to reveal any significant lesions of the
central or peripheral nervous systems...
1 other challenged cock bird is also showing ataxia (43 months p.i.).
snip...
94/01.19/7.1
Saturday, January 9, 2016
Transmission of sheep-bovine spongiform encephalopathy to pigs Research
article
News Release Media Contact: TPWD News, news@tpwd.texas.gov,
512-389-8030
June 20, 2016
TPW Commission Adopts Amended Deer Movement Rules
AUSTIN – After extensive public testimony, the Texas Parks and Wildlife
Commission Monday approved an amended set of regulations for artificial movement
of deer by permit as part of the state’s chronic wasting disease (CWD)
management plan.
Adopted provisions are the result of extensive collaboration between the
Texas Parks and Wildlife Department (TPWD), Texas Animal Health Commission
(TAHC), the deer breeding community and landowners to address concerns over the
future of permitted unnatural deer movement qualifications following the
discovery of CWD in 2015, while providing continued protection against the fatal
neurological disease for Texas’ 4 million free-ranging and captive deer.
“This is bigger than the interests of one group and it’s not about choosing
winners or losers,” said Texas Parks and Wildlife Commission Chairman T. Dan
Friedkin. “The fundamental issue is how best to protect our state’s deer herds
from a deadly disease. The overwhelming amount of interest this issue has
generated illustrates just how passionate Texans are about deer and our deer
hunting heritage. The actions taken by the commission today are the result of
extensive deliberation with input from all stakeholders, and I applaud the many
individuals and groups from all over the state who took the time and effort to
remain engaged in the process until the end.”
Among the provisions adopted by the commission include a suite of options
to attain artificial deer movement qualified status through a multilevel system
of ante-mortem (“live”) and post-mortem deer testing for CWD. Key changes to the
rules include:
•Establishing a minimum level of post-mortem testing in deer breeding
facilities at 80 percent
•Providing an opportunity for all captive deer breeders to test-up to
Transfer Category 1 (TC1) status through 50 percent ante-mortem testing of their
entire herd (a proposed May 15, 2017, testing deadline was eliminated from the
rules) and breeders may choose their preferred ante-mortem testing means
(rectal, lymph nodes, tonsillar etc.).
•Clarification that the 5-year, 80 percent eligible mortality testing
requirement to realize TC1 status may be obtained through testing a 5-year
average of annual mortalities and deer breeders may use a 3:1 ratio to
substitute live tests for post-mortem tests to meet required testing thresholds.
•Property owners may request to expand release sites, provided release site
requirements apply to the expanded acreage.
•Elimination of testing requirements on Trap, Transfer and Transplant
(Triple T) release sites.
Details of CWD rule changes affecting specific artificial deer movement
permits are available online at www.tpwd.texas.gov/cwd/.
The rules take effect upon completion of programming modifications to the
Texas Wildlife Information Management System (TWIMS), but no later than Aug. 15,
2016, and apply to the movement of deer under TPWD permits, including Triple T,
DMP (deer management permit), TTP (trap, transport and process) and deer
breeder.
2016-06-20
Texas Parks & Wildlife tightens rules on deer breeders
By Tim Eaton - American-Statesman Staff
Posted: 1:36 p.m. Monday, June 20, 2016
Highlights
Commission vote came after months of talks.
Deer breeders walk out of Texas Parks & Wildlife Commission hearing
Anti-breeding forces want to see strict regulations to protect wild deer
from chronic wasting disease.
The Texas Parks and Wildlife Commission adopted new rules Monday to combat
a disease found in deer, but the new rules could put a strain on many of the
state’s 1,300 deer breeding businesses.
The commission’s vote came after months of discussions with interested
groups, including breeders, ranch owners who sell hunting leases, environmental
groups and livestock organizations.
snip...
Deer breeding opponent Jenny Sanders, who is executive director of Texans
for Saving our Hunting Heritage, called the commission vote a win.
Sanders, who also has served a manager on the 11,300-acre Temple Ranch near
Freer in South Texas, said chronic wasting disease as a major threat to
white-tailed deer in Texas and to the multibillion-dollar hunting industry. The
state had the responsibility to protect the state’s 4 million white-tailed deer,
she said.
Not everyone agreed with Sanders and the commissioners.
snip...
Hugo Berlanga, a former member of the Texas House from Corpus Christi and
owner of a deer breeding business, said the breeding industry in Texas is
already on “life support.” The new regulations will come with high costs and
will force some breeding operations of out business, he said.
“They have done so much damage to breeders,” he said.
Berlanga said the process was rigged to the benefit of large ranch owners
who fear competition from smaller businesses that are often close to metro
areas.
“It’s a bunch of elitists. I can’t explain it any simpler than that,” said
Berlanga, a board member of the Texas Deer Association.
Sanders, whose group’s members include some representatives from major
Texas ranches, has rejected the notion that the breeder fight is about large
ranch owners trying to eliminate competition from breeders.
Rather, she said in a recent op-ed published in the San Antonio Express
News, that “a small group of deer breeders” has “embarked on an effort to
undermine” the efforts of the Texas Parks and Wildlife Department.
Josh Havens, a spokesman for the Texas Parks and Wildlife Department, said
the commission has heard testimony from a number of individuals who either
represent themselves, organizations and landowners.
“(T)his is a public resource issue, and the commission will make their
decision based on science and what is in the best interest of the states
wildlife and hunting heritage,” Havens wrote in a text message.
Berry, the South Texas breeder, said his and other breeders’ fight won’t
end with the commission vote.
An already-filed lawsuit is going to be part of the answer, he said.
“That’s going to be the next step before the Legislature,” he said.
>>> “(T)his is a public resource issue, and the commission will
make their decision based on science and what is in the best interest of the
states wildlife and hunting heritage,” Havens wrote in a text
message.<<<
Bravo!...tss
Deer Breeders Hint At Suing State Over New Chronic Wasting Regulations
By Ryan Poppe • 2 hours ago
snip...
“Under the emergency rules breeders tested about 11-thousand animals, these
rules could potentially have the effect of testing 50-plus thousand animals,
that’s an increase of about five-times the amount of testing," Tarleton
explains.
Tarleton says deer breeders and captive deer ranchers are ready to take
their fight against the regulations to the courtroom.
Carter Smith is the executive director of the Texas Parks and Wildlife
Department. He says the new rules are in place to make sure the disease does not
spread across both the wild and captive deer population.
“The debate is not about low-fence vs. high-fence or breeders vs.
anti-breeders, it’s how do we help try to detect and contain a disease that
affects the entirety of our state’s 4-million deer," Smith explains.
Smith says last month the agency found a mule deer in the Texas Panhandle
that had died from chronic wasting disease in the wild. So far Parks and
Wildlife officials have not detected transmission of the disease among the
state’s whitetail deer population.
>>>“The debate is not about low-fence vs. high-fence or breeders
vs. anti-breeders, it’s how do we help try to detect and contain a disease that
affects the entirety of our state’s 4-million deer," Smith
explains.<<<
Bravo!...tss
*** Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force
Base Scrapie Experiment 1964 ***
*** How Did CWD Get Way Down In Medina County, Texas?
Confucius ponders...
Could the Scrapie experiments back around 1964 at Moore Air Force near
Mission, Texas, could this area have been ground zero for CWD TSE Prion (besides
the CWD cases that have waltzed across the Texas, New Mexico border near WSMR
Trans Pecos region since around 2001)?
Epidemiology of Scrapie in the United States 1977
snip...
Scrapie Field Trial Experiments Mission, Texas
A Scrapie Field Trial was developed at Mission, Texas, to provide
additional information for the eradication program on the epidemiology of
natural scrapie. The Mission Field Trial Station is located on 450 acres of
pastureland, part of the former Moore Air Force Base, near Mission, Texas. It
was designed to bring previously exposed, and later also unexposed, sheep or
goats to the Station and maintain and breed them under close observation for
extended periods to determine which animals would develop scrapie and define
more closely the natural spread and other epidemiological aspects of the
disease.
The 547 previously exposed sheep brought to the Mission Station beginning
in 1964 were of the Cheviot, Hampshire, Montadale, or Suffolk breeds. They were
purchased as field outbreaks occurred, and represented 21 bloodlines in which
scrapie had been diagnosed. Upon arrival at the Station, the sheep were
maintained on pasture, with supplemental feeding as necessary. The station was
divided into 2 areas: (1) a series of pastures and-pens occupied by male animals
only, and (2) a series of pastures and pens occupied by females and young
progeny of both sexes. ...
snip...see full text ;
Mission, Texas Scrapie transmission to cattle study
Wilbur Clarke (reference the Mission, Texas scrapie transmission
transmission to cattle study) is now the State Veterinarian for Montana based at
Helena.
I was given confidential access to sections from the Clarke scrapie-cattle
transmission experiment. Details of the experimental design were as supplied
previously by Dr. Wrathall (copy of relevant information appended). Only 3
animals (2 inoculated with 2nd pass Suffolk scrapie and 1 inoculated with Angora
goat passaged scrapie) showed clinical signs. Clinical signs were characterised
by weakness, ''a stilted hindlimb gait'', disorientation, ataxia and,
terminally, lateral recumbency. The two cattle from which I examined material
were inocluated at 8 months of age and developed signs 36 months pi (goat
scrapie inoculum) and 49 months pi (one of the Suffolk scrapie inoculated)
respectively. This latter animal was killed at 58 months of age and so the
clinical duration was only 1 month. The neuropathology was somewhat different
from BSE or the Stetsonville TME in cattle. Vacuolar changes were minimal, to
the extent that detection REQUIRED CAREFUL SEARCHING. Conversely astrocyte
hypertrophy was a widespread and prominent feature. The material requires
DETAILED NEUROPATHOLOGICAL ASSESSMENT BUT WHETHER OR NOT THIS WILL BE DONE
REMAINS A QUESTION.
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and
compared with natural cases {the following was written but with a single line
marked through it ''first passage (by this route)}...TSS
resulted in a more rapidly progressive clinical disease with repeated
episodes of synocopy ending in coma. One control animal became affected, it is
believed through contamination of inoculum (?saline). Further CWD transmissions
were carried out by Dick Marsh into ferret, mink and squirrel monkey.
Transmission occurred in ALL of these species with the shortest incubation
period in the ferret.
snip...
Spongiform Encephalopathy in Captive Wild ZOO BSE INQUIRY
Tuesday, April 19, 2016
Docket No. FDA-2013-N-0764 for Animal Feed Regulatory Program Standards
Singeltary Comment Submission
Thursday, June 09, 2016
Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force Base
Scrapie TSE Prion Experiment 1964
How Did CWD Get Way Down In Medina County, Texas?
Tuesday, June 21, 2016
TPW Commission Adopts Amended Deer Movement Rules and Some Deer breeders
walk out of hearing on chronic wasting disease CWD TSE Prion
Thursday, June 16, 2016
Help fight this fatal disease CWD TSE PRION threat to Texas wild deer herd
WISCONSIN CHRONIC WASTING DISEASE CWD TSE PRION SPIRALING FURTHER INTO THE
ABYSS UPDATE
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
Friday, April 22, 2016
COLORADO CHRONIC WASTING DISEASE CWD TSE PRION SURVEILLANCE AND TESTING
PROGRAM IS MINIMAL AND LIMITED
*** SEE CWD HIGH INFECTION RATE MAPS FOR COLORADO ! ***
Saturday, May 28, 2016
*** Infection and detection of PrPCWD in soil from CWD infected farm in
Korea Prion 2016 Tokyo ***
Friday, February 05, 2016
Report of the Committee on Wildlife Diseases FY2015 CWD TSE PRION
Detections in Farmed Cervids and Wild
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
Monday, May 02, 2016
*** Zoonotic Potential of CWD Prions: An Update Prion 2016 Tokyo ***
Tuesday, June 07, 2016
*** Comparison of two US sheep scrapie isolates supports identification as
separate strains ***
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
Friday, June 03, 2016
Chronic Wasting Disease CWD TSE Prion Surveillance and Testing in Texas, a
very concerning situation
Saturday, May 28, 2016
TPWD gives in to Breeders again and postponed their decision regarding
proposed changes to state regulations for managing CWD allowing the TSE Prion to
spread further
Sunday, May 22, 2016
TEXAS CWD DEER BREEDERS PLEA TO GOVERNOR ABBOTT TO CIRCUMVENT TPWD SOUND
SCIENCE TO LET DISEASE SPREAD
Sunday, June 12, 2016
TPWD Special Meeting Chronic Wasting Disease Response Rules June 20, 2016
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
Friday, April 22, 2016
*** Texas Scrapie Confirmed in a Hartley County Sheep where CWD was
detected in a Mule Deer
Monday, April 25, 2016
TEXAS Nilgai Exotic Antelope Let Loose for Trophy Hunts Blamed for
Spreading Cattle Tick Fever, and what about CWD TSE Prion Disease ?
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
Friday, February 05, 2016
TEXAS NEW CHRONIC WASTING DISEASE CWD CASE DISCOVERD AT CAPTIVE DEER
RELEASE SITE
Saturday, January 23, 2016
Texas new interim rule governing Deer Management Permit (DMP) activities as
part of the state’s response to the detection of chronic wasting disease (CWD)
in captive deer populations
Sunday, January 17, 2016
Texas 10,000 deer in Texas tested for deadly disease CWD TSE, but not
tested much in the most logical place, the five-mile radius around the Medina
County captive-deer facility where it was discovered
Friday, January 15, 2016
TEXAS PARKS & WILDLIFE CWD Ante-Mortem Testing Symposium Texas Disposal
Systems Events Pavilion January 12, 2016
Sunday, January 10, 2016
TEXAS MEDIA REPORTING A BIT OF GOOD NEWS ON CWD TESTING SO FAR INSTEAD OF
TAHC which is still mum, still refusing timely updates to the public TSE PRION
DISEASE
Tuesday, December 29, 2015
*** TEXAS MONTHLY CHRONIC WASTING DISEASE CWD JANUARY 2016 DEER BREEDERS
STILL DON'T GET IT $
Chronic Wasting Unease
*** The emergence of a deadly disease has wildlife officials and deer
breeders eyeing each other suspiciously. ***
Monday, November 16, 2015
*** TEXAS PARKS AND WILDLIFE DEPARTMENT EXECUTIVE DIRECTOR ORDER NO.
015-006
*** Chronic Wasting Disease (CWD) immediate danger to the white-tailed deer
and mule deer resources of Texas
Saturday, November 14, 2015
TEXAS CAPTIVE BREEDER CHRONIC WASTING DISEASE CWD 2 MORE SUSPECTS DECTECTED
BRINGING NUMBER TO 7 DETECTED IN CAPTIVE BREEDER (if/when the last two are
confirmed).
Thursday, November 05, 2015
*** TPW Commission Adopts Interim Deer Breeder Movement Rules
Friday, October 09, 2015
Texas TWA Chronic Wasting Disease TSE Prion Webinars and Meeting October
2015
Saturday, October 03, 2015
TEXAS CHRONIC WASTING DISEASE CWD TSE PRION GOD MUST NOT BE A TEXAN 2002 TO
2015
Thursday, September 24, 2015
TEXAS Hunters Asked to Submit Samples for Chronic Wasting Disease CWD TSE
Prion Testing
*** I cannot stress enough to all of you, for the sake of your family and
mine, before putting anything in the freezer, have those deer tested for CWD.
...terry
***raw and uncut
Sunday, August 23, 2015
TAHC Chronic Wasting Disease CWD TSE Prion and how to put lipstick on a pig
and take her to the dance in Texas
Friday, August 07, 2015
*** Texas CWD Captive, and then there were 4 ?
Thursday, August 06, 2015
*** WE HAVE LOST TEXAS TO CWD TASK FORCE CATERING TO INDUSTRY
Tuesday, July 21, 2015
*** Texas CWD Medina County Herd Investigation Update July 16, 2015 ***
Thursday, July 09, 2015
TEXAS Chronic Wasting Disease (CWD) Herd Plan for Trace-Forward Exposed
Herd with Testing of Exposed Animals
Wednesday, July 01, 2015
TEXAS Chronic Wasting Disease Detected in Medina County Captive Deer
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
Thursday, May 02, 2013
*** Chronic Wasting Disease (CWD) Texas Important Update on OBEX ONLY
TEXTING
Friday, February 26, 2016
TEXAS Hartley County Mule Deer Tests Positive for Chronic Wasting Disease
Thursday, May 02, 2013
*** Chronic Wasting Disease (CWD) Texas Important Update on OBEX ONLY
TEXTING
Monday, February 11, 2013
TEXAS CHRONIC WASTING DISEASE CWD Four New Positives Found in Trans Pecos
Tuesday, July 10, 2012
Chronic Wasting Disease Detected in Far West Texas
Monday, March 26, 2012
Texas Prepares for Chronic Wasting Disease CWD Possibility in Far West
Texas
2011 – 2012
Friday, October 28, 2011
CWD Herd Monitoring Program to be Enforced Jan. 2012 TEXAS
Greetings TAHC et al,
A kind greetings from Bacliff, Texas.
In reply to ;
Texas Animal Health Commission (TAHC) Announcement October 27, 2011
I kindly submit the following ;
***for anyone interested, here is some history of CWD along the Texas, New
Mexico border, and my attempt to keep up with it...terry
snip...
see history CWD Texas, New Mexico Border ;
Monday, March 26, 2012
3 CASES OF CWD FOUND NEW MEXICO MULE DEER SEVERAL MILES FROM TEXAS BORDER
Sunday, October 04, 2009
CWD NEW MEXICO SPREADING SOUTH TO TEXAS 2009 2009 Summary of Chronic
Wasting Disease in New Mexico New Mexico Department of Game and Fish
I could go on, for more see ;
Thursday, March 31, 2016
*** Chronic Wasting Disease CWD TSE Prion Roundup USA April 1, 2016 ***
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 ***
Tuesday, June 14, 2016
*** Chronic Wasting Disease (CWD) in a moose from Selbu in Sør-Trøndelag
Norway ***
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 well as non-ruminants such as cats and dogs as
well, as soon as possible for the following reasons...
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 ;
*** 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
Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer
and Elk in Animal Feed Singeltary Submission
*** Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats Terry Singeltary
Sr. Submission ***
Monday, November 16, 2015
*** Docket No. APHIS-2007-0127 Scrapie in Sheep and Goats Terry Singeltary
Sr. Submission ***
Draft Guidance for Industry on Ensuring Safety of Animal Feed Maintained
and Fed On-Farm; Availability
# 203 entitled “Ensuring Safety of Animal Feed Maintained and Fed
On-Farm.”
Terry S. Singeltary Sr. submission ;
Docket No. APHIS-2014-0107 Bovine Spongiform Encephalopathy; Importation of
Animals and Animal Products Singeltary Submission
Posted: 12/30/2014ID: APHIS-2014-0107-0001
Notice: Environmental Impact Statements; Availability, etc.: Animal Carcass
Management
Document ID: APHIS-2013-0044-0001 Docket ID: APHIS-2013-0044 Comment ID:
APHIS-2013-0044-0002
(APHIS) Notice: Agency Information Collection Activities; Proposals,
Submissions, and Approvals: Chronic Wasting Disease Herd Certification Program
Agency Information Collection Activities; Proposals, Submissions, and Approvals:
Chronic Wasting Disease Herd Certification Program (Document ID
APHIS-2011-0032-0001)
*** 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.
***Moreover, sporadic disease has never been observed in breeding colonies
or primate research laboratories, most notably among hundreds of animals over
several decades of study at the National Institutes of Health25, and in nearly
twenty older animals continuously housed in our own facility.***
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
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...
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. ...
”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.
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
Monday, June 20, 2016
Specified Risk Materials SRMs BSE TSE Prion Program
Sent: Monday, January 08,2001 3:03 PM
TO: freas@CBS5055530.CBER.FDA.GOV
FDA CJD BSE TSE Prion Scientific Advisors and Consultants Staff January
2001 Meeting Singeltary Submission
2001 FDA CJD TSE Prion Singeltary Submission
15 November 1999
British Medical Journal
vCJD in the USA * BSE in U.S.
2 January 2000
British Medical Journal
U.S. Scientist should be concerned with a CJD epidemic in the U.S., as well
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14,
2001 JAMA
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
To the Editor: In their Research Letter, Dr Gibbons and colleagues1
reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD)
has been stable since 1985. These estimates, however, are based only on reported
cases, and do not include misdiagnosed or preclinical cases. It seems to me that
misdiagnosis alone would drastically change these figures. An unknown number of
persons with a diagnosis of Alzheimer disease in fact may have CJD, although
only a small number of these patients receive the postmortem examination
necessary to make this diagnosis. Furthermore, only a few states have made CJD
reportable. Human and animal transmissible spongiform encephalopathies should be
reportable nationwide and internationally.
Terry S. Singeltary, Sr Bacliff, Tex
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob
disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323.
26 March 2003
Terry S. Singeltary, retired (medically) CJD WATCH
I lost my mother to hvCJD (Heidenhain Variant CJD). I would like to comment
on the CDC's attempts to monitor the occurrence of emerging forms of CJD.
Asante, Collinge et al [1] have reported that BSE transmission to the
129-methionine genotype can lead to an alternate phenotype that is
indistinguishable from type 2 PrPSc, the commonest sporadic CJD. However, CJD
and all human TSEs are not reportable nationally. CJD and all human TSEs must be
made reportable in every state and internationally. I hope that the CDC does not
continue to expect us to still believe that the 85%+ of all CJD cases which are
sporadic are all spontaneous, without route/source. We have many TSEs in the USA
in both animal and man. CWD in deer/elk is spreading rapidly and CWD does
transmit to mink, ferret, cattle, and squirrel monkey by intracerebral
inoculation. With the known incubation periods in other TSEs, oral transmission
studies of CWD may take much longer. Every victim/family of CJD/TSEs should be
asked about route and source of this agent. To prolong this will only spread the
agent and needlessly expose others. In light of the findings of Asante and
Collinge et al, there should be drastic measures to safeguard the medical and
surgical arena from sporadic CJDs and all human TSEs. I only ponder how many
sporadic CJDs in the USA are type 2 PrPSc?
Singeltary Submission 2016
Alzheimer-type brain pathology may be transmitted by grafts of dura mater
26/01/2016
Terry S. Singeltary Sr. Bacliff, Texas USA 77518 flounder9@verizon.net
posted by Terry S. Singeltary Sr. at
2:33 PM
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