Colorado Deer with CWD Chronic Wasting Disease TSE Prion found near Nucla
Subject: Colorado Deer with CWD chronic wasting disease found near Nucla
CPW News Release
5/23/2017
Deer with wasting disease found near Nucla
FOR IMMEDIATE RELEASE
Joe Lewandowski CPW SW Region PIO 970-375-6708
Deer with wasting disease found near Nucla in western Colorado MONTROSE, Colo. – A mature buck deer that was found dead near Nucla in March has tested positive for chronic wasting disease, Colorado Parks and Wildlife has reported. The deer was found on private property near town. This is the first CWD-positive deer found by Colorado Parks and Wildlife in the west end of Montrose County in Game Management Unit 61. In the last year, seven deer between Montrose and Delta tested positive for the disease. Deer that tested positive for the disease included three that were suspect and were euthanized, three deer taken on game-damage permits and one buck harvested during the regular hunting season. CWD is a neurological disease that afflicts some deer, elk and moose. In order to determine how widespread the disease is in this part of the state, Colorado Parks and Wildlife will require mandatory testing of deer harvested by hunters this year in Game Management Units 61, 62, 64 and 65. A random sample of hunters who draw licenses in these units will receive a letter this summer explaining they must submit harvested deer for mandatory testing. There will be no charge for the test. Hunters in these units and any other GMU in Colorado who are not selected for mandatory testing may voluntarily submit deer, elk and moose for a CWD test. The fee for voluntary submissions is $25 Elsewhere in Colorado, CPW will require mandatory testing for deer harvested in Game Management Units 7, 8, 9, 11, 12, 13, 19, 20, 22, 23, 24, 33, 131, 191, 211 and 231. As in the Montrose area, a random sample of hunters in these units will be notified that they must submit harvested deer for testing. For more information about CWD, go to this section of the CPW website: http://cpw.state.co.us/learn/Pages/ResearchCWD.aspx. ###
CPW is an enterprise agency, relying primarily on license sales, state parks fees and registration fees to support its operations, including: 42 state parks and more than 350 wildlife areas covering approximately 900,000 acres, management of fishing and hunting, wildlife watching, camping, motorized and non-motorized trails, boating and outdoor education. CPW's work contributes approximately $6 billion in total economic impact annually throughout Colorado.
Tuesday, July 12, 2016
Colorado Chronic Wasting Disease CWD TSE Prion discovered in one deer in Montrose County
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 ! ***
Sunday, November 13, 2011
COLORADO CWD CJD TSE PRION REPORTING 2011
Chronic Wasting Disease—Prion Disease in the Wild
Steve Bunk Published: April 13, 2004
Colorado State's Salman argues that current surveillance is primarily a series of reactions to reported cases, rather than a systematic strategy designed to determine where and at what prevalence the disease exists and where it's absent. The estimated prevalence is about 1% in elk and 2.5% in deer. But Salman says, “We don't have a good idea of areas in which we are saying we haven't found the disease because these areas are not yet, in my estimation, negative for the disease. Scrapie is a wonderful example of systematic surveillance but, to be fair to the decision-makers and technical people involved with CWD, surveillance on wildlife species is very difficult.”
The USDA's Goeldner declares, “We have the goal and the hope to eradicate the disease from the farm population.” But Colorado Department of Wildlife veterinarian and CWD expert Mike Miller warns, “Given existing tools, it seems unlikely that CWD can be eradicated from free-ranging populations once established.”
Surveillance for chronic wasting disease in Colorado
TSE Conference 2 May 1997 M. W. Miller, Colorado Division of Wildlife, Fort Collins E. S. Williams, University of Wyoming, Laramie Chronic wasting disease (CWD) is a spongiform encephalopathy of mule deer (Odocoileus hemionus), white-tailed deer (O. virginianus), and Rocky Mountain elk (Cervus elaphus nelsoni). To date, the only documented focus of CWD is in northcentral Colorado and southeastern Wyoming. To understand epizootiology of CWD, to determine its distribution, and to reliably model its dynamics and effects on wild populations, methods for efficiently and effectively surveying free-ranging populations of deer and elk are needed. Active surveillance of free-ranging cervids in the endemic areas began in 1981, but has been more intense since 1992.
Two strategies are currently being employed in the endemic areas of Colorado and Wyoming, as well as many other states and provinces in western North America, to survey for CWD:
1) Recognition, collection, and submission of suspect CWD cases to veterinary diagnostic laboratories by wildlife agencies. The CWD *suspect* profile includes deer or elk; over18 months of age; emaciated and showing abnormal behavior, and/or increased salivation, and/or tremor, stumbling, incoordination, and/or difficulty in swallowing, and/or polydipsia/polyuria.
Diagnostic evaluation of each suspect includes brain histopathology and, in more recent years, sometimes includes ancillary evaluation by immunocytochemistry, SAF, or Western blot. Using this approach, about 80 CWD-positive cervids were identified in the five-county endemic area in Colorado and Wyoming since 1981; at least 168 additional *suspects* submitted from throughout Colorado and Wyoming have been examined and found to be affected by maladies other than CWD.
2) Collections of heads (or brain stem and tonsils) from harvested deer and elk via check stations or specified drop-off points. Brains were examined by histopathology and, beginning in 1995, immunocytochemistry; selected cases were also examined for SAF and by Western blot analysis.
Estimated prevalences from pooled harvest survey data were 0.4% in elk (1992-1996; n=487; range 0-1%/management unit/yr) and about 2.9% (1983-1996; n=687; range 0-7.3%/management unit/yr) in endemic populations; none of over 300 samples from cervids harvested outside endemic areas of Colorado and Wyoming were positive.
Based on results obtained to date, we believe this combination of extensive clinical surveillance and intensive population sampling represents an effective and efficient strategy for detecting, studying, and monitoring CWD in free-ranging cervid populations in Colorado and Wyoming, and also may be useful in studies of CWD occurrence and distribution elsewhere.
SCIENCE
Weighing 'Mad Cow' Risks in American Deer and Elk
By SANDRA BLAKESLEEFEB. 23, 1999
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As a 30-year-old deer hunter lies dying at his home near Salt Lake City, consumer advocates and Government regulators are squabbling over a terrifying question that cannot be answered to anyone's satisfaction: Is it possible to contract a version of ''mad cow disease'' from eating deer or elk?
Mad cow disease appeared in British cattle in the mid-1980's and caused an epidemic that left the brains of infected animals spongy and riddled with gum-like strings. Eventually, the British Government ordered the destruction of more than four million animals. At least 34 young people in Britain contracted a human form of the fatal disease, possibly from eating infected beef or from coming into contact with products made from sick cows.
Nothing similar has turned up in American beef, although experts believe one in a million cows will develop the disease spontaneously. Animal feeding practices have been revised to reduce chances of transmission. But a similar disease has been seen in sheep and mink, and people are now worried about a version of mad cow disease endemic in deer and elk in parts of Colorado and Wyoming, raising the possibility that hunters who eat infected animals may similarly develop a human form of the deer and elk malady, called chronic wasting disease.
The cow, elk, deer and human diseases belong to a family of disorders called transmissible spongiform encephalopathies, or T.S.E. The human form, Creutzfeldt-Jakob disease or C.J.D., occurs in three varieties. Most cases are spontaneous with no known cause. About 10 percent of cases run in families, linked to inherited gene defects. The British cases are called new variant C.J.D.
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In all three varieties, the disease agent is believed to be not a virus or bacterium but a mysterious particle called a prion -- a kind of renegade protein that transforms normal proteins into abnormal, indestructible substances that create spongy holes in the brain.
Prion diseases have been found in 85 species, passing easily between some animals and not others. When a prion ''jumps'' species, new T.S.E. diseases are created that can be more or less virulent for reasons no one can explain.
This is the question raised by the deer hunter's case: Does he have a new variant of Creutzfeldt-Jakob disease contracted from deer and elk, and if so, what does it look like? Health and wildlife officials point out there is no proof that mad deer or elk disease has ''jumped'' to humans. At the same time, consumer advocates point to the dying hunter, Doug McEwen, whose illness is uncannily similar to that seen in the young victims of mad cow.
According to his wife, Tracie, Mr. McEwen hunted in season, and often ate deer and elk that he bagged. But he never hunted in Colorado or Wyoming, where chronic wasting disease is found. So no one knows if he contracted his brain disease from animals or spontaneously developed the illness destroying his brain.
Moreover, Mr. McEwen was a frequent donor of blood plasma and his plasma was pooled with many blood products and shipped to 21 countries. Blood safety officials here and abroad at first quarantined the blood products but have since let some of them be used.
In part because of the mad cow outbreak in Britain, the United States Food and Drug Administration barred blood banks from accepting donations from people with family members with C.J.D. But given that it is not known if blood or plasma can transmit the disease, and the fact that almost all Americans with the disease have the sporadic form, which tends not to involve the blood, the Public Health Service and food and drug agency changed the nation's blood policy in August. Now only those people with familial or genetic versions of C.J.D. are prohibited from donating blood, said Dr. Jay Epstein of the Center for Biologics Evaluation and Research at the drug agency.
American public health officials say that chronic wasting disease in deer and elk and Mr. McEwen's plasma donations pose no threat to people. Careful epidemiological surveys have not shown any increase in the type of brain disease afflicting Mr. McEwen and no indication that frequent users of blood products, like hemophiliacs, have a higher incidence of any kind of C.J.D., said Dr. Lawrence Schonberger, an epidemiologist who coordinates surveillance activities for Creutzfeldt-Jakob disease at the Centers for Disease Control and Prevention in Atlanta.
Many people are unconvinced. ''The fact that we have a disease in elk and deer at levels equivalent to mad cow disease at the height of the British epidemic is truly alarming,'' said John Stauber, director of the Center for Media and Democracy, a group that reports on government and industry public relations, and the author of ''Mad Cow U.S.A.,'' a book critical of American health officials. In both cases, an estimated 6 percent of animals carry the infection.
Mr. Stauber and others interested in the disease say they distrust Government estimates, citing, among other things, published reports estimating that 6 to 8 percent of people who are told they have Alzheimer's disease may actually have a form of C.J.D., said Dr. Thomas Pringle, a scientific consultant for the Sperling Foundation, a charitable public health organization.
''Was nothing learned from the British experience?'' asked Dr. Pringle, who maintains an encyclopedic Web page on the subject (www.mad-cow.org). ''Why are we repeating the gamble they took?''
British officials for years adamantly denied the cow disease was any threat to humans, he said.
Mr. McEwen, a territory manager of a groceries firm who lives in Kaysville, Utah, first showed symptoms in June when he forgot how to spell his wife's name and could no longer do simple arithmetic. His condition worsened rapidly; by the end of the summer he was forced to quit his job.
Neurologists carried out scores of tests, including brain scans and spinal taps, to no avail, until Nov. 24, when they finally took a brain biopsy. The next day, Mr. McEwen was given a diagnosis of C.J.D.
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Creutzfeldt-Jakob disease strikes one in a million people over age 50, said Dr. Michael Hansen, a scientist who closely follows the issue for Consumer's Union. The disease strikes fewer than one in a billion people worldwide at Mr. McEwen's age, 30. Moreover, in Mr. McEwen's case, the disease has moved with astounding rapidity, leaving him near death, unable to recognize his two young daughters or his wife.
Alarmed by Mr. McEwen's age and the speed of his illness, state health officials sent a brain tissue sample to Dr. Pierluigi Gambetti, an expert on prion diseases at Case Western Reserve University in Cleveland. Dr. Gambetti ruled out most known causes of C.J.D. Mr. McEwen never received transplanted tissues that might have been infected with abnormal prions. His disease was not inherited and it definitely did not come from cattle. The diagnosis: sporadic C.J.D., meaning no known cause. Cases like that are rare but not unknown, Dr. Gambetti said.
But Dr. Pringle and others do not accept this diagnosis as final. They point out that no one knows what chronic wasting disease would look like in a human, and tests to determine the nature of such a disease have not been done.
All mammals have prion proteins whose structures vary by just a few building blocks called amino acids, Dr. Pringle said. The difference between a cow and a human prion might be eight of these building blocks out of hundreds. But when the abnormal cow prion co-opts the normal human prion, a new abnormal human prion -- and a new disease -- is formed. It looks exactly like a C.J.D.-related human prion but it can be more insidious. If the new variety of human prion is injected into a cat, yet another disease can be created. It may be more infectious or less infectious in the cat. Such experiments in which the infectious prion of one species is ''passaged'' into another species is a standard test for sorting out various T.S.E.'s.
''There are many imponderables in these experiments,'' said Dr. Byron Caughey, a prion expert at the National Institute of Health Rocky Mountain Laboratory in Hamilton, Mont. ''One prion is an infectious unit large enough to give you the disease. But it can be terribly inefficient going across species. A person could take in a billion infectious units from a deer or elk and never get sick in his lifetime,'' he said.
Dr. Schonberger said that there were no plans to carry out interspecies tests on Mr. McEwen's brain tissue because it is clear that he has a natural human form of the disease and because there is no increase of C.J.D. where deer and elk hunting occurs.
According to wildlife officials, chronic wasting disease affects about 5 percent of the deer and 1 percent of the elk found in a small area in northeastern Colorado and southern Wyoming. Sick animals drool excessively, stagger around and lose weight before dying. Hunters in several states are required to turn in deer and elk heads so that the brain tissue can be tested. So far, the disease in the wild has not spread beyond Colorado and Wyoming.
Game farms are another story. The disease is found in captive deer and elk herds in three states -- South Dakota, Nebraska and Oklahoma -- and in the Canadian province of Saskatchewan, said Dr. Beth Williams, the nation's leading expert on chronic wasting disease, at the University of Wyoming in Laramie. The disease was reported in the mid-1960's at the Wildlife Research Station in Fort Collins, Colo., where it eventually wiped out 90 percent of the animals. But before people knew what was happening, many infected animals were sold to game farms or zoos elsewhere for breeding, thus spreading the infection. Ranchers made large profits selling antlers to Asia, where they are used in making herbal remedies and aphrodisiacs.
The disease was first observed in the wild in 1981, Dr. Williams said. No one knows how it spreads. The infectious prion may be shed in saliva, feces or placenta and if wild animals come across downed fences, they might step on contaminated ground. There is new evidence that the prion may be concentrated in inflamed skin cells, suggesting that the disease could be spread by scratching posts or trees in the wild.
But Dr. Mike Miller, a veterinarian with the Colorado Department of Wildlife who is familiar with the problem, said thousands of people had consumed deer and elk meat and field dressed hundreds of infected animals in the Fort Collins area over the last 25 years. ''We make no secret of where the disease occurs,'' and leave it up to hunters to decide the risks for themselves, he said, although hunters are advised to wear gloves when cutting up animals and to avoid brain and spinal cord tissue.
But a deeper reason to worry is the diabolical nature of the infectious prion particle. It seemingly cannot be destroyed. When medical instruments contaminated with prions are boiled at high temperatures for 30 minutes, the prions remain infectious -- and have passed the infection from person to person. When infected materials are incinerated, the ash contains prions, which remain infectious.
This problem is highly relevant to Mrs. McEwen, who has learned that a local funeral home will not embalm her husband if an autopsy, exposing brain tissue, is performed. Several prion laboratories want her to donate her husband's brain to them exclusively, said Mel Steiger, also from Salt Lake City, whose wife died last spring from C.J.D. and who is now helping Mrs. McEwen. ''She has not decided what to do,'' he said.
Meanwhile, Federal officials are in a regulatory bind, weighing risks and benefits. The risks of spreading C.J.D. contracted from deer and elk seem minuscule compared with threatening jobs (Colorado's Department of Wildlife gets half its income from selling deer and elk tags), frightening hunters needlessly and shaking confidence in the nation's blood supply.
Dr. Schonberger is confident that the best decisions have been made on the available evidence. ''If something happens down the road people will come and chop our heads off,'' he said. ''But I don't think that's going to happen.''
Correction: February 24, 1999, Wednesday An article in Science Times yesterday about a type of ''mad cow disease'' in American deer misstated a recent change in Federal policy on donated blood. Health officials continue to bar donations from anyone with a risk factor for a similar illness, Creutzfeldt-Jakob disease. But if a donation has already been made by someone with a risk factor, the blood and blood products will no longer be withdrawn. Health officials say they have found no evidence that the most common forms of Creutzfeldt-Jakob are contracted through blood.
Dr. Schonberger is confident that the best decisions have been made on the available evidence. ''If something happens down the road people will come and chop our heads off,'' he said. ''But I don't think that's going to happen.''
Date: Tue, 9 Jan 2001 16:49:00 -0800
From: "Terry S. Singeltary Sr."
Reply-To: Bovine Spongiform Encephalopathy
To: BSE-L@uni-karlsruhe.de
######### Bovine Spongiform Encephalopathy #########
Greetings List Members,
I was lucky enough to sit in on this BSE conference call today and even managed to ask a question. that is when the trouble started.
I submitted a version of my notes to Sandra Blakeslee of the New York Times, whom seemed very upset, and rightly so.
"They tell me it is a closed meeting and they will release whatever information they deem fit. Rather infuriating."
and i would have been doing just fine, until i asked my question. i was surprised my time to ask a question so quick.
(understand, these are taken from my notes for now. the spelling of names and such could be off.)
[host Richard Barns] and now a question from Terry S. Singeltary of CJD Watch.
[TSS] yes, thank you, U.S. cattle, what kind of guarantee can you give for serum or tissue donor herds?
[no answer, you could hear in the back ground, mumbling and 'we can't. have him ask the question again.]
[host Richard] could you repeat the question?
[TSS] U.S. cattle, what kind of guarantee can you give for serum or tissue donor herds?
[not sure whom ask this] what group are you with?
[TSS] CJD Watch, my Mom died from hvCJD and we are tracking CJD world-wide.
[not sure who is speaking] could you please disconnect Mr. Singeltary
[TSS] you are not going to answer my question?
[not sure whom speaking] NO
snip...see full text ;
In Confidence - Perceptions of unconventional slow virus diseases of animals in the USA - APRIL-MAY 1989 - G A H Wells
22
Visits to Colorado State University, College of Veterinary Medicine and the Wyoming Game and Fish Department, Sybille Wildlife Research and Conservation Education Unit.
The main objective here was to obtain some understanding of CWD. A visit was made to the University of wyoming Game and Fish Department, Sybille wildlife Research and Conservation Education Unit where most of the cases of CWD have occurred. The Sybille Wildlife facility is situated some 50 miles northeast of Laramie, Wyoming through the Laramie Mountains. Here most of the hoofed big game species of North America; Hule Deer (odocoileus hemionus), Whitetail Deer (Odocoileus virginianus), Elk (Cervis canadensis) Mountain Goat (Oreamnos americana), Bighorn Sheep (0vis canadensis} and Pronghorn (Antilocapra americana) and some other wildlife species are kept in small numbers for experimental use in the investigation of wildlife diseases.
A colony of the blackfooted ferret (Hustela nigripes) has been established because of its imminent extinction. At present there are only 35 but it is proposed to breed up to 200 and then, probably in 1991, re-introduce them into the wild in a nation wide operation. Blackfooted ferret diet is mainly Prairie Dog (Cynoms spp.) and it is thought that the elimination of this species from large areas by poisoning campaigns in the past has been responsible for the precipitous ferret decline.
The buildings and pens at the facility are entirely of wooden/log construction with heavy duty wire mesh fences. Pen floors are bare earth. A long race connecting many different areas within the facility enables movement of deer and antelope between pens when necessary. There is provision for holding deer of different sizes in a custom built crush for bleeding and treatments.
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The educational role of the unit includes school visits to provide instruction in the work of the department and to promote conservation. I was accompanied on this visit by Stuart Young and Beth Williams. on arrival I was introduced to Hughie Dawson who has managed the facility for some 20 years.
CWD occurred principally in two locations, this one at Sybille and in a similar facility at Fort Collins, Colorado, some 120 miles southwest. It was estimated that in total probably 60-10 cases of CWD have occurred.
It was difficult to gain a clear account of incidence and temporal sequence of events ( - this presumably is data awaiting publication - see below) but during the period 1981-84, 10-15 cases occurred at the Sybille facility. Recollections as to the relative total numbers of cases at each facility were confusing. Beth Williams recalled that more cases had occurred in the Colorado facility.
The morbidity amongst mule deer in the facilities ie. those of the natural potentially exposed group has been about 90% with 100% mortality. the age distribution of affected deer was very similar to that in ESE. The clinical duration of cases was 6-8 weeks. Mortality in CWD cases was greatest in winter months which can be very cold.
When the problem was fully appreciated both the Sybille and the Colorado facilities were depopulated. All cervids were culled but Pronghorn, Bighorn Sheep and Mountain goat, where present simultaneously in the facility, were retained. There have been no cases of CWD in these non cervid species.
A few cases continue to occur at Sybille, the last was 4 months ago.
24
An account of the occurrence of CWD at the Colorado facility was obtained from Terry spraker, Diagnostic Laboratory, CSU College of Veterinary Medicine, Fort Collins. He examined tissues from cases of CWD at the Colorado facility some time prior to Beth Williams's involvement and examination of brains which resulted in the initial diagnosis. The deer holding facilities in Colorado comprise the Colorado Division of Wildlife Research Pen, established 10 years ago and some older deer pens at the Foot Hills Campus of CSU, close to Fort Collins. Originally there were just 1-2 cases CWD/year and a total of 24 over several years. In contrast to Beth Williams recollection Terry Spraker thought more cases had‘ occurred at Sybille than in Colorado. The cull at the Colorado facility involved 20-30 clinically normal deer. Early lesions in dorsal nucleus of the vagus and olfactory cortex were found in (some) of these deer. At the time of the cull here Pronghorn was the only other hoofed species present. Bighorn sheep and Mountain Goat were introduced only one year after the cull and occupied ground where CWD had occurred. Immediately after depopulation the ground was ploughed and disinfection was carried out using ?1% NaOH. The buildings/pens were not changed. There has been no recurrence of disease at the Colorado facility since the cull.
25
Transmission Studies
Mule deer transmissions of CWD were by intracerebral inoculation and compared with natural cases (‘’first passage by this route’’ MARKED OUT...TSS) resulted in a more rapidly progressive clinical disease with repeated episodes of synocopy ending in coma. one control animal became affected, it is J 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.
Mouse and hamster transmissions were attempted at Wyoming State Diagnostic Laboratory, Laramie and at CSU Fort Collins but were unsuccessful.
Also at the Wyoming State Diagnostic Laboratory, Laramie, transmission to goats was attempted. In 1984 three goats were inoculated intracerebrally with a 10% CWD brain suspension. one goat, untreated, was placed in contact with the CWD inoculated goats and three controls, housed separately, received saline intracerebrally. To date these animals remain healthy.
Epidemiology of CWD
Descriptive epidemiological data has been collected from the two wildlife facilities and a publication is in preparation.
The occurrence of CWD must be viewed against the context of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite its subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA viewed it as a wildlife problem and consequently not their province! Thus
26
there have been no specific epidemiological studies, other than information gained from noting the occurrence of cases. Because of the relatively short term nature of the programmed research at the facilities it has not been possible to keep Mule Deer under the appropriate experimental circumstances or for sufficient periods to establish horizontal or maternal transmission. Beth Williams is of the view that the occurrence of CWD at Sybille is entirely related to propagative spread by contagion. Investigations have failed to identify any common source of infection and the incident has presented a protracted time course with sporadic cases throughout. There is no evidence that wild born deer were responsible for introduction of the disease to the facility.
I asked Hughie Dawson about the nutritional aspects of the deer kept at Sybille. Mule Deer calves are reared on condensed milk and homogenised or pasteurised domestic cow's milk from birth to 1 month or to 6 months. some would be given "Lamb milk replacer" which has a higher butter fat content than either of the former products, but is derived also from domestic cow's milk. It was thought that at the Colorado facility calves would receive only "evaporated milk". Calves are weaned on to a pelletted feed containing corn, wheat bran and linseed meal with no crude mineral suppliment. Salt licks ("sulphur blocks") which have a specific mineral composition are supplied.
CWD has occurred or is suspected to have occurred in establishments supplied with Mule Deer from the Colorado facility. In some cases evidence for this is tenuous. For example, it is understood that Denver zoo state that "they have not had cases of CWD" and yet they have had cases of Mule Deer succumbing to a chronic wasting disorder which was not diagnosed. A case of CWD occurred in a Mule Deer in Toronto zoo in 1976. The animal in
27
question came from Denver zoo but was originally from the Colorado wildlife facility.
Pathology of CWD
A paper (Williams et al) is in preparation on the distribution of brain lesions in CWD. Vacuolar changes occur predominantly in the dorsal nucleus of the vagus nerve (this nucleus is invariably affected), the hypothalamus and the olfactory cortex with occasional vacuolation of the olfactory tract white matter.
Cerebellar lesions are sometimes present but there are very few changes in the spinal cord which probably accounts for the rarity of ataxia clinically. As in sheep scrapie the hypothalamic lesions correlate with the common clinical occurrence of polydipsia. Beth Williams is aware of occasional neuronal vacuoles occurring in the red nucleus of clinically normal deer! Spraker has added that he has experienced vacuoles in neurons of Gasserian ganglia and at the level of the obex in normal deer.
It has never been reported but Pat Merz carried out SAF detection on CWD brain material. Work may be undertaken with NIH on the immunohistological demonstration of PrP in sections but to date there has been no PrP work.
Does CWD occur in free-living cervids?
There is some, mostly circumstantial, evidence that CWD occurs in free-living cervids but to what extent, if at all, this represents an established reservoir of infection in the wild is not known.
At Sybille two Mule Deer orphans (wild caught) and a White—tail Deer (Odocoileus virginianus) hybrid developed clinical signs when only 2 1/2 years of age.
28
An Elk (Cervus canadensis) wild caught as an adult, presumed 2 years old, developed signs when 3-4 years old.
Another group of elk, wild caught 400 miles from the facility, with an age range 2-8 years, old subsequently developed the disease in the facility (?period of captivity). The location of capture relative to the facility did not apparently rule out that they may have at some time had fence-line nose contact with animals in the facility!
Cases have also occurred in Mule Deer that were obtained from the wild within one hour of birth but these were never kept completely isolated through to maturity.
Also at Sybille there has been one case of CWD diagnosed in a free ranging Elk. It was killed in Sybille Canyon 3 miles from the facility. It could have had fence-line contact with captive Mule Deer in the facility.
Similar incidents had occurred in Colorado. In 1985 a free-ranging affected Elk was caught in the Rocky Mountain National Park within a 2 mile radius of the Colorado Division of Wildlife Research Pen. In 1986 and again in 1987 a single affected Mule Deer on each occasion was caught within a 5 mile radius of the Pen. These latter cases occurred within 2 years of the -cervid cull at the Pen (?1985). Brain tissue from the free—ranging Elk brain was inoculated into mice but for some reason these were kept for only 6 months and then the experiment was abandoned.
A specific exercise has been carried out by Beth Williams with the Wyoming State Diagnostic Laboratory and Fish Department to sample the brains of healthy wild Mule Deer for histological examination. On two separate occasions the first in 1985 and again in 1987 a total of 150 Mule Deer
29
brains were collected from areas of, and ajacent to, Sybille Canyon. These deer would have been shot under a game permit by local hunters. As they were brought down from the hills to the Game station for the mandatory registration of the kill the heads were removed and ages estimated. Most were 2-5 year old with a few 6 year old. For obvious reasons hunters were reluctant to give up stag heads. Thus, but for 15-20 brains from stags, examinations were on brains from females. No evidence of CWD lesions was found in any of these brains. However, it was considered that sporadic cases of CWD, should they occur in the wild population, would soon become separated from the herd and fall prey to coyotes (Canis latrans).
The possibility of any reservoir of infection in wild cervids originating from scrapie in domestic sheep flocks seems remote. Scrapie has been recorded in only three flocks in Wyoming since 1947 and Beth Williams could recall only one previous occurrence in 1966. This had involved a Suffolk flock close to the border with Nebraska. However, there has been one new confirmed and a suspected affected flock this year in Wyoming. In the latter a ewe bought—in from an Illinois flock is incriminated.
Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr Bob Davis. At or about that time, allegedly, some" scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep. Whether they were scrapie infected sheep or not is unclear. There were domestic sheep and goats present in the facility also in the 1960's but there is no evidence that these animals developed scrapie. During the 60's hybridization studies between the Bighorn and domestic sheep were carried
30
out, again, without evidence of scrapie. Domestic goats were also kept at Sybille in the 1960's.
Spraker considers that the nasal route is responsible for transmission of CWD through nose to nose contact, which may well occur also between captive and free—living individuals.
In domestic cattle of which about 15-20 adults were necropsied per year at the Diagnostic Laboratory, CSU., Spraker had not encountered any lesions suggesting BSE. Polioencephalomalacia (PEM) and Encephalic Listeriosis were the most common morphologic neuropathological diagnoses. No bovine rabies was seen.
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Appendix I
VISIT TO USA - OR A E WRATHALL — INFO ON BSE AND SCRAPIE
Dr Clark lately of the Scrapie Research Unit, Mission Texas has I successfully transmitted ovine and caprine Scrapie to cattle. The experimental results have not been published but there are plans to do this. This work was initiated in 1978. A summary of it is:-
Expt A 6 Her x Jer calves born in 1978 were inoculated as follows with a 2nd Suffolk scrapie passage:- i/c 1ml; i/m, 5ml; s/c 5ml; oral 30ml.
1/6 went down after 48 months with a scrapie/BS2-like disease.
Expt B 6 Her or Jer or HxJ calves were inoculated with angora Goat virus 2/6 went down similarly after 36 months.
Expt C Mice inoculated from brains of calves/cattle in expts A & B were resistant, only 1/20 going down with scrapie and this was the reason given for not publishing.
Diagnosis in A, B, C was by histopath. No reports on SAF were given.
2. Dr Warren Foote indicated success so far in eliminating scrapie in offspring from experimentally— (and naturally) infected sheep by ET. He had found difficulty in obtaining embryos from naturally infected sheep (cf SPA).
3. Prof. A Robertson gave a brief accout of BSE. The us approach was to
32
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. BSE was not reported in USA.
4. Scrapie incidents (ie affected flocks) have shown a dramatic increase since 1978. In 1953 when the National Control scheme was started there were 10-14 incidents, in 1978 - 1 and in 1988 so far 60.
5. Scrapie agent was reported to have been isolated from a solitary fetus.
6. A western blotting diagnostic technique (? on PrP) shows some promise.
7. Results of a questionnaire sent to 33 states on" the subject of the national sheep scrapie programme survey indicated
17/33 wished to drop it
6/33 wished to develop it
8/33 had few sheep and were neutral
Information obtained from Dr Wrathall‘s notes of a meeting of the U.S. Animal Health Association at Little Rock, Arkansas Nov. 1988.
33
snip...see full text ;
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. ...
snip...see full text ;
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 its 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.
*** Spraker suggested an interesting explanation for the occurrence of CWD. The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr. Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at this site. When deer were introduced to the pens they occupied ground that had previously been occupied by sheep.
SPONTANEOUS ATYPICAL BOVINE SPONGIFORM ENCEPHALOPATHY ***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.***
CWD TSE PRION ROUNDUP
CWD of deer and elk is spreading across North America and cannot be stopped.
The tse prion aka mad cow type disease is not your normal pathogen.
The TSE prion disease survives ashing to 600 degrees celsius, that’s around 1112 degrees farenheit.
You cannot cook the TSE prion disease out of meat. you can take the ash and mix it with saline and inject that ash into a mouse, and the mouse will go down with TSE.
Prion Infected Meat-and-Bone Meal Is Still Infectious after Biodiesel Production as well.
The TSE prion agent also survives Simulated Wastewater Treatment Processes.
IN fact, you should also know that the TSE Prion agent will survive in the environment for years, if not decades.
You can bury it and it will not go away.
The TSE agent is capable of infected your water table i.e. Detection of protease-resistant cervid prion protein in water from a CWD-endemic area.
it’s not your ordinary pathogen you can just cook it out and be done with.
that’s what’s so worrisome about Iatrogenic mode of transmission, a simple autoclave will not kill this TSE prion agent.
cwd to humans, consumption, exposure, sub-clinical, iatrogenic, what if ?
i strenuously urge you all to rethink this cutting of funds for research of the TSE Prion disease.
*** DECEMBER 2016 CDC EMERGING INFECTIOUS DISEASE JOURNAL CWD HORIZONTAL TRANSMISSION
*** INFECTIOUS AGENT OF SHEEP SCRAPIE MAY PERSIST IN THE ENVIRONMENT FOR AT LEAST 16 YEARS ***
GUDMUNDUR GEORGSSON1, SIGURDUR SIGURDARSON2 AND PAUL BROWN3
Title: Pathological features of chronic wasting disease in reindeer and demonstration of horizontal transmission
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.
***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.
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
Dr. Schonberger is confident that the best decisions have been made on the available evidence. ''If something happens down the road people will come and chop our heads off,'' he said. ''But I don't think that's going to happen.''
seems if my primitive education does not fail me, intracranial means inside the skull, and peroral means by the mouth. seems the price of tse prion poker just keeps going up...terry
Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Location: Virus and Prion Research Title: Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease Author item Moore, Sarah item Kunkle, Robert item Kondru, Naveen item Manne, Sireesha item Smith, Jodi item Kanthasamy, Anumantha item West Greenlee, M item Greenlee, Justin Submitted to: Prion Publication Type: Abstract Only Publication Acceptance Date: 3/15/2017 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Aims: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of cervids. We previously demonstrated that disease-associated prion protein (PrPSc) can be detected in the brain and retina from pigs challenged intracranially or orally with the CWD agent. In that study, neurological signs consistent with prion disease were observed only in one pig: an intracranially challenged pig that was euthanized at 64 months post-challenge. The purpose of this study was to use an antigen-capture immunoassay (EIA) and real-time quaking-induced conversion (QuIC) to determine whether PrPSc is present in lymphoid tissues from pigs challenged with the CWD agent.
Methods: At two months of age, crossbred pigs were challenged by the intracranial route (n=20), oral route (n=19), or were left unchallenged (n=9). At approximately 6 months of age, the time at which commercial pigs reach market weight, half of the pigs in each group were culled (<6 challenge="" groups="" month="" pigs="" remaining="" the="">6 month challenge groups) were allowed to incubate for up to 73 months post challenge (mpc). The retropharyngeal lymph node (RPLN) was screened for the presence of PrPSc by EIA and immunohistochemistry (IHC). The RPLN, palatine tonsil, and mesenteric lymph node (MLN) from 6-7 pigs per challenge group were also tested using EIA and QuIC. Results: PrPSc was not detected by EIA and IHC in any RPLNs. All tonsils and MLNs were negative by IHC, though the MLN from one pig in the oral <6 5="" 6="" at="" by="" detected="" eia.="" examined="" group="" in="" intracranial="" least="" lymphoid="" month="" months="" of="" one="" pigs="" positive="" prpsc="" quic="" the="" tissues="" was="">6 months group, 5/6 pigs in the oral <6 4="" and="" group="" months="" oral="">6 months group. Overall, the MLN was positive in 14/19 (74%) of samples examined, the RPLN in 8/18 (44%), and the tonsil in 10/25 (40%).
Conclusions: This study demonstrates that PrPSc accumulates in lymphoid tissues from pigs challenged intracranially or orally with the CWD agent, and can be detected as early as 4 months after challenge. CWD-infected pigs rarely develop clinical disease and if they do, they do so after a long incubation period. This raises the possibility that CWD-infected pigs could shed prions into their environment long before they develop clinical disease. Furthermore, lymphoid tissues from CWD-infected pigs could present a potential source of CWD infectivity in the animal and human food chains.
Porcine prion protein amyloid
Per Hammarstr€om and Sofie Nystr€om* IFM-Department of Chemistry; Link€oping University; Link€oping, Sweden
ABSTRACT. Mammalian prions are composed of misfolded aggregated prion protein (PrP) with amyloid-like features.
Prions are zoonotic disease agents that infect a wide variety of mammalian species including humans. Mammals and by-products thereof which are frequently encountered in daily life are most important for human health. It is established that bovine prions (BSE) can infect humans while there is no such evidence for any other prion susceptible species in the human food chain (sheep, goat, elk, deer) and largely prion resistant species (pig) or susceptible and resistant pets (cat and dogs, respectively). PrPs from these species have been characterized using biochemistry, biophysics and neurobiology. Recently we studied PrPs from several mammals in vitro and found evidence for generic amyloidogenicity as well as cross-seeding fibril formation activity of all PrPs on the human PrP sequence regardless if the original species was resistant or susceptible to prion disease. Porcine PrP amyloidogenicity was among the studied. Experimentally inoculated pigs as well as transgenic mouse lines overexpressing porcine PrP have, in the past, been used to investigate the possibility of prion transmission in pigs. The pig is a species with extraordinarily wide use within human daily life with over a billion pigs harvested for human consumption each year. Here we discuss the possibility that the largely prion disease resistant pig can be a clinically silent carrier of replicating prions.
KEYWORDS. prion, pig, amyloid fibril, misfolding, transmissibility, seeding, TSE, prion strain, strain adaptation
snip...
What about pigs? In several recent papers which in our view have not received sufficient attention the notion of prion resistant pigs was challenged by generation of transgenic mice with knocked out endogenous PrP and overexpressed PoPrP. Different lines of tgPoPrP mouse were proven to be susceptible to clinical disease triggered by a variety of prion strains, suggesting that the surrogate host species (mouse) and prion strain are more important than what PrP sequence it expresses for neurotoxicity to commence. In more detail, Torres and colleagues experimentally subjected transgenic mouse lines expressing porcine PrP to a number of different TSE isolates.24-26 Their studies demonstrate that prion infection is strain specific when porcine PrP is overexpressed (4x) and used as in vivo substrate. PoTg001 mice inoculated with classical scrapie, regardless of donor genotype, resisted prion disease both at first and second passage (Fig. 3b). On the other hand, Nor98 scrapie (Atypical scrapie) as well as BSE from both cattle and BoTg mouse model resulted in clinical disease in the PoTg001 mice. However, in the first generation, disease progression was slow. Incubation time until death was as long as 600 d and the hit rate was low. This indicates that disease has barely developed by the time the mice reach their natural life span limit which in this study was set to 650 d Already in the second passage the hit rate was 100 % and the incubation time was cut in half (Fig. 3b). No further shortening of incubation time was observed upon third passage. This shows that PoPrP is capable of forming infectious and neurotoxic prions in vivo if triggered by a compatible prion strain and if given enough time to develop. Both BSE and Nor98 rapidly adapts to the PoPrP host sequence, resulting in higher penetrance as well as in markedly shorter life span already in the second passage, well within the limits of normal life span for a mouse.
There are several crucial variables which impact the susceptibility of prion diseases and transmission studies.27 PrP sequence of host, PrP sequence of prion, prion strain, prion dosage, PrP expression level of host, host genetic background, route of transmission and neuroinvasiveness if peripherally infected.28 Importantly the PrP expression level corresponds to the rate of prion disease onset.1 This likely reflects 2 converging variables: a) PrP as a substrate to the prion misfolding reaction i.e. selfcatalyzed conversion and b) PrP as a mediator of neurotoxicity through interactions with misfolded PrP within prions.
The non-homologous recPrPs presented here and in,12 easily adapt to each other and form amyloid fibrils in accordance with what is seen in vivo when inoculum composed of BoPrP used to challenge mice expressing PoPrP (Fig. 3b).24-26 A review of the literature showed that BSE strains have a high degree of penetrance in both experimental and accidental transmission. Over 50% of the species reported to be susceptible to prion disease were infected by a BSE strain.19 Recent data form our lab shows that the promiscuity of BoPrP fibrils holds true also in the case of recombinant in vitro experiments. When cross-seeding human, bovine, porcine, feline and canine PrPs with any of the other, the recBoPrP seed outcompetes the other seeds in all instances except when the HuPrP acted as substrate (Data not shown). In this case recPoPrP fibrils have the highest seeding efficiency (Fig. 1). These findings in combination with the Torres experiments,24-26 implicate that a PoPrP substrate in vivo (in pigs) could adapt to an amyloidogenic prion strain of bovine or ovine prion disease and hence replicate in the new host.
For adaptation of experimental strains through multiple passages, donors are selected based on neurotoxicity (that is on TSE disease phenotype) not on basis of amyloid fibril formation. Hence the traits of transmissible amyloidotypic prion strains may be largely unexplored if these strains require more time to transform to neurotoxic strains e.g. as proposed by Baskakov’s model of deformed templating.8 There is experimental evidence for BSE transmission into pig via parenteral routes.16 with an incubation period of 2–3 years, well within what is to be considered normal lifespan. For a breeding sow in industrial scale pig farming that is 3–5 y (Bojne Andersson, personal communication).29,30 In small scale and hobby farming both sows and boars may be kept significantly longer. Collinge and Clarke.31 describe how prion titers reach transmissibility levels well before the prion burden is high enough to be neurotoxic and cause clinical disease. It is known that prion strains need time and serial passages to adapt. Knowing that pigs in modern farming are rarely kept for enough time for clinical signs to emerge in prion infected pigs it is important to be vigilant if there is a sporadic porcine spongiform encephalopathy (PSE) as has been seen in cattle (BASE) and sheep (Nor98). Hypothetically such a sporadic and then infectious event could further adapt and over a few generations have reached the point where clinical PSE is established within the time frame where pigs are being slaughtered for human consumption (Fig. 4).
FIGURE 4. Potential prion strain adaptation in pig. The red horizontal gradient indicates the hietherto unkown prion toxicity tolerance threshold for pigs, the blue vertical line indicates normal slaughter age for industrial pig farming, the green vertical line indicates the normal lifespan of a breeding sow in industrial scale pig farming, orange areas indicate window of neurotoxic prions before onset of clinical disease (dark orange indicates subclinical BSE as reported by Wells et al,16 pale orange indicate hypothetic outcome of PSE and strain adaptation. On the outmost right a potential subclinical sporadic PSE.
USE OF MATERIALS DERIVED FROM PIG IN VIEW OF PORCINE PrP AMYLOID
The pig is the most versatile species used by humans for food and other applications. Over 1,5 billion pigs are slaughtered each year worldwide for human use.32 Besides juicy pork sirloin other parts from pig are used for making remarkably diverse things such as musical instruments, china, leather, explosives, lubricants etc. Pig offal is used for human medicine, e.g., hormone preparations such as insulin and cerebrolysin, in xenographs, sutures, heparin and in gelatin for drug capsules.33,34
And that means not only pork, it means your pigskin wallet, catgut surgical suture...in tallow, in butter. It is undoubtedly in the blood supply. DC Gajdusek (From R. Rhodes ''Deadly Feast'' 35)
While the late Carleton Gajdusek had strong views in diverse areas of prion biology, according to journalist Richard Rhodes,35 he was correct on his prediction on BSE prions (vCJD) in the blood supply18 (see text box above). An opinionated scientist can sometimes be ignored due to a judgment of character and Gajdusek was certainly provocative. Notwithstanding society should remain vigilant on the possibility that Gajdusek was also prophetic on porcine prions given the exceptionally wide spread use of pigs in everyday human life and medicine. As discussed previously it is currently not established what relations transmissible neurotoxic prion strains and amyloid morphotypic mature APrP strains have. Given the hypotheses that amyloidotypic PrP conformations can transmit with low neurotoxicity.7,36 it is interesting to reflect on possible implications. Pigs are slaughtered at 6–8 months of age. Because amyloid deposition is associated with old age, this is likely far too young for spontaneous development of APrP amyloid from PoPrP as well as other amyloidogenic proteins. From the perspective of seeded amyloidogenesis it is however a potential ideal case for highly transmissible titers of APrP (Fig. 4). In such a scenario the potential of porcine prions constitutes the perfect storm, clinically silent due to neurotoxic resistance and with high titers of transmissibility. When it comes to prions CNS material is most heavily infected. In addition, however, fat tissue (to make lard and tallow) is known to harbor extraordinary amounts of amyloid in systemic amyloidoses.37 Amyloid fibrils of misfolded large proteins (AA, AL, ATTR) are notoriously hydrophobic due to the abnormal exposure of hydrophobic residues which normally in the folded structure being hidden in the protein core. The amyloid accumulation in fat tissue is likely a phase-separation from a rather hydrophilic environment in circulation toward the hydrophobic environment provided by adipocytes. Adipose tissue could in addition represent an in vivo environment well suitable for fibril formation. What about APrP?
In analysis of mice expressing Glycophosphatidylinositol, (GPI)-anchorless PrP, abdominal fat contains appreciable amounts of infectious prions in APrP isoform stained with ThS.38 Notably mice overexpressing anchorless PrP provides a silent carrier status for a long time prior to presenting symptoms and is severely afflicted by amyloid fibril formation following scrapie (RML) infection.39 Recall that this study showed that GPI-anchored PrP is needed to present clinical neurotoxicity. Evidently circulating anchorless-PrP (analogous to recPrP) is more amyloidogenic compared to GPI-anchored PrP and is poorly neuroinvasive.28 Amyloidosis is systemic in anchorless-PrP mice and is not limited to fat but is also found as extensive cardiac amyloid deposits.39 Interestingly cardiac APrP was recently reported in one BSE inoculated rhesus macaque which showed symptoms of cardiac distress prior to death from prion neurotoxicity.40 It is noteworthy that transgenic mice expressing PoPrP appear sensitive to strains with biochemical features of amyloidogenic prion strains i.e., BSE and Nor98.25,26,36 (Fig. 3b). We recently adopted the parallel inregister intermolecular b-sheet structural model of the APrP fibril from the Caughey lab to rationalize cross-seeding between various PrP sequences.12,41 It is tempting to use this structural model to speculate on the adaptation of mono-N-glycolsylated PoPrP at the expense of double-N-glycolylated PrP in the original BSE inoculum reported in the Torres experiments.25,26 In this APrP model monoglycosylated PrP at N197 is structurally compatible while N181 is not, due to burial in the in-register intermolecular cross-beta sheet (Fig. 5).
It appears that amyloidotypic prion strains, APrP, are transmissible but associated with lower neurotoxicity compared to diffuse aggregated PrP associated with synaptic PrP accumulations. It is possible that the amino acid substitutions in PoPrP compared to HuPrP and BoPrP are important for neurotoxic signal transmission (Fig. 2b, 5). The main issue hereby is that transmissibility of APrP will remain undetected unless used for surveillance. AA amyloidosis is frequent in many animals (e.g. cattle and birds) but is exceptionally rare in pigs.42 suggesting that APrP should it reside in pig fat would be traceable using newly developed screening methods.37
CONCLUDING REMARKS
Should the topic of porcine PrP amyloid be more of a worry than of mere academic interest? Well perhaps. Prions are particularly insidious pathogens. A recent outbreak of peripheral neuropathy in human, suggests that exposure to aerosolized porcine brain is deleterious for human health.43,44 Aerosolization is a known vector for prions at least under experimental conditions.45-47 where a mere single exposure was enough for transmission in transgenic mice. HuPrP is seedable with BoPrP seeds and even more so with PoPrP seed (Fig. 1), indicating that humans could be infected by porcine APrP prions while neurotoxicity associated with spongiform encephalopathy if such a disease existed is even less clear. Importantly transgenic mice over-expressing PoPrP are susceptible to BSE and BSE passaged through domestic pigs implicating that efficient downstream neurotoxicity pathways in the mouse, a susceptible host for prion disease neurotoxicity is augmenting the TSE phenotype.25,26 Prions in silent carrier hosts can be infectious to a third species. Data from Collinge and coworkers.21 propose that species considered to be prion free may be carriers of replicating prions. Especially this may be of concern for promiscuous prion strains such as BSE.19,48 It is rather established that prions can exist in both replicating and neurotoxic conformations.49,50 and this can alter the way in which new host organisms can react upon cross-species transmission.51 The na€ıve host can either be totally resistant to prion infection as well as remain non-infectious, become a silent non-symptomatic but infectious carrier of disease or be afflicted by disease with short or long incubation time. The host can harbor and/or propagate the donor strain or convert the strain conformation to adapt it to the na€ıve host species. The latter would facilitate infection and shorten the incubation time in a consecutive event of intra-species transmission. It may be advisable to avoid procedures and exposure without proper biosafety precautions as the knowledge of silence carrier species is poor. One case of iatrogenic CJD in recipient of porcine dura mater graft has been reported in the literature.52 The significance of this finding is still unknown. The low public awareness in this matter is exemplified by the practice of using proteolytic peptide mixtures prepared from porcine brains (Cerebrolysin) as a nootropic drug. While Cerebrolysin may be beneficial for treatment of severe diseases such as vascular dementia,53 a long term follow-up of such a product for recreational use is recommended.
DISCLOSURE OF POTENTIAL CONFLICTS OF INTEREST
No potential conflicts of interest were disclosed
FUNDING
This work was supported by G€oran Gustafsson foundation, the Swedish research council Grant #2011-5804 (PH) and the Swedish Alzheimer association (SN).
REFERENCES
CONFIDENTIAL EXPERIMENTAL PORCINE SPONGIFORM ENCEPHALOPATHY While this clearly is a cause for concern we should not jump to the conclusion that this means that pigs will necessarily be infected by bone and meat meal fed by the oral route as is the case with cattle. ...
we cannot rule out the possibility that unrecognised subclinical spongiform encephalopathy could be present in British pigs though there is no evidence for this: only with parenteral/implantable pharmaceuticals/devices is the theoretical risk to humans of sufficient concern to consider any action.
Our records show that while some use is made of porcine materials in medicinal products, the only products which would appear to be in a hypothetically ''higher risk'' area are the adrenocorticotrophic hormone for which the source material comes from outside the United Kingdom, namely America China Sweden France and Germany. The products are manufactured by Ferring and Armour. A further product, ''Zenoderm Corium implant'' manufactured by Ethicon, makes use of porcine skin - which is not considered to be a ''high risk'' tissue, but one of its uses is described in the data sheet as ''in dural replacement''. This product is sourced from the United Kingdom.....
snip...see much more here ;
WEDNESDAY, APRIL 05, 2017
Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease
TUESDAY, APRIL 18, 2017
*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
Dr. Schonberger is confident that the best decisions have been made on the available evidence. ''If something happens down the road people will come and chop our heads off,'' he said. ''But I don't think that's going to happen.''
*** 10:30 First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
Dr Stefanie Czub University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency Canada
*** WDA 2016 NEW YORK ***
We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species.
We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions.
Student Presentations Session 2
The species barriers and public health threat of CWD and BSE prions
Ms. Kristen Davenport1, Dr. Davin Henderson1, Dr. Candace Mathiason1, Dr. Edward Hoover1 1Colorado State University
Chronic wasting disease (CWD) is spreading rapidly through cervid populations in the USA. Bovine spongiform encephalopathy (BSE, mad cow disease) arose in the 1980s because cattle were fed recycled animal protein. These and other prion diseases are caused by abnormal folding of the normal prion protein (PrP) into a disease causing form (PrPd), which is pathogenic to nervous system cells and can cause subsequent PrP to misfold. CWD spreads among cervids very efficiently, but it has not yet infected humans. On the other hand, BSE was spread only when cattle consumed infected bovine or ovine tissue, but did infect humans and other species. The objective of this research is to understand the role of PrP structure in cross-species infection by CWD and BSE. To study the propensity of each species’ PrP to be induced to misfold by the presence of PrPd from verious species, we have used an in vitro system that permits detection of PrPd in real-time. We measured the conversion efficiency of various combinations of PrPd seeds and PrP substrate combinations. We observed the cross-species behavior of CWD and BSE, in addition to feline-adapted CWD and BSE. We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species. ***We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions. CWD is unique among prion diseases in its rapid spread in natural populations. BSE prions are essentially unaltered upon passage to a new species, while CWD adapts to the new species. This adaptation has consequences for surveillance of humans exposed to CWD. Wildlife Disease Risk Communication Research Contributes to Wildlife Trust Administration Exploring perceptions about chronic wasting disease risks among wildlife and agriculture professionals and stakeholders
PRION 2016 TOKYO
Zoonotic Potential of CWD Prions: An Update
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
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.
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.
PMCA Detection of CWD Infection in Cervid and Non-Cervid Species
Hoover, Edward Arthur Colorado State University-Fort Collins, Fort Collins, CO, United States
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).***
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.
Dr. Schonberger is confident that the best decisions have been made on the available evidence. ''If something happens down the road people will come and chop our heads off,'' he said. ''But I don't think that's going to happen.''
SPONTANEOUS ATYPICAL BOVINE SPONGIFORM ENCEPHALOPATHY
***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.***
WEDNESDAY, MARCH 15, 2017
In vitro amplification of H-type atypical bovine spongiform encephalopathy by protein misfolding cyclic amplification
"When considering the atypical L-BSE and H-BSE diseases of cattle, they have been assessed in both non-human primate and transgenic mouse bioassays (with mice transgenic for human PRNP) and both model systems indicate that H-BSE and L-BSE may have increased zoonotic potential compare with C-BSE. The detection of all types of BSE is therefore of significant importance."
Monday, January 09, 2017
Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle CDC Volume 23, Number 2—February 2017
Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
SPONTANEOUS ATYPICAL BOVINE SPONGIFORM ENCEPHALOPATHY
***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.***
Wednesday, December 21, 2016
TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES 2016 ANNUAL REPORT ARS RESEARCH
Tuesday, September 06, 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
Saturday, July 23, 2016
BOVINE SPONGIFORM ENCEPHALOPATHY BSE TSE PRION SURVEILLANCE, TESTING, AND SRM REMOVAL UNITED STATE OF AMERICA UPDATE JULY 2016
Tuesday, July 26, 2016
Atypical Bovine Spongiform Encephalopathy BSE TSE Prion UPDATE JULY 2016
Monday, June 20, 2016
Specified Risk Materials SRMs BSE TSE Prion Program
Thursday, December 08, 2016
USDA APHIS National Scrapie Eradication Program October 2016 Monthly Report Fiscal Year 2017 atypical NOR-98 Scrapie
Monday, May 02, 2016
*** Zoonotic Potential of CWD Prions: An Update Prion 2016 Tokyo ***
PRION2017
*** 10:30 First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress
Dr Stefanie Czub University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency Canada
WEDNESDAY, MAY 03, 2017
*** First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques
Dr. Schonberger is confident that the best decisions have been made on the available evidence. ''If something happens down the road people will come and chop our heads off,'' he said. ''But I don't think that's going to happen.''
SUNDAY, MAY 21, 2017
Arkansas Chronic Wasting Disease CWD TSE Prion Roundup 212 Cases Confirmed To Date
THURSDAY, MAY 18, 2017
Minnesota Four more farmed white-tailed deer test positive for Chronic Wasting Disease CWD TSE Prion
MONDAY, MARCH 27, 2017
Wyoming CWD Postive Mule Deer Doe Near Pinedale
MONDAY, MARCH 20, 2017
Wisconsin CWD TSE Prion Annual Roundup 441 positive
TUESDAY, MARCH 14, 2017
Iowa 12 deer test positive for chronic wasting disease from 2016-17 hunting seasons
MONDAY, MARCH 13, 2017
CHRONIC WASTING DISEASE CWD TSE PRION UDATE March 13, 2017
FRIDAY, MARCH 10, 2017
Nebraska Tests confirm spread of CWD to Lancaster County
SATURDAY, MAY 20, 2017
Missouri CWD TSE PRION Surveillance and Monitoring
THURSDAY, MARCH 09, 2017
Missouri MDC REPORTS TWO CASES OF CWD IN ST. CLAIR COUNTY
SATURDAY, MARCH 04, 2017
Maryland DNR Six Deer Test Positive for Chronic Wasting Disease
WEDNESDAY, MARCH 01, 2017
South central Pennsylvania Captive Deer Tests Positive for Chronic Wasting Disease
MONDAY, MAY 15, 2017
Pennsylvania 25 more deer test positive for CWD TSE PRION in the wild
MONDAY, MAY 15, 2017
TEXAS New CWD TSE PRION Case Discovered at Fifth Captive Deer Breeding Facility
SUNDAY, MAY 14, 2017
85th Legislative Session 2017 AND THE TEXAS TWO STEP Chronic Wasting Disease CWD TSE Prion, and paying to play
FRIDAY, MARCH 31, 2017
TPWD UPDATE CWD TSE Prion 49 confirmed cases and unwanted firsts for Texas
MONDAY, MARCH 13, 2017
CHRONIC WASTING DISEASE CWD TSE PRION UDATE March 13, 2017
SATURDAY, JANUARY 14, 2017
CHRONIC WASTING DISEASE CWD TSE PRION GLOBAL UPDATE JANUARY 14, 2017
MONDAY, APRIL 17, 2017
Wildlife advocates see wolves as 'best natural defense' against chronic wasting disease
NO WAY! this is an extremely stupid move, and very, very, dangerous...
MONDAY, MARCH 8, 2010
Canine Spongiform Encephalopathy aka MAD DOG DISEASE
http://caninespongiformencephalopathy.blogspot.com/2010/03/canine-spongiform-encephalopathy-aka.html
TUESDAY, APRIL 18, 2017
*** EXTREME USA FDA PART 589 TSE PRION FEED LOOP HOLE STILL EXIST, AND PRICE OF POKER GOES UP ***
WEDNESDAY, MAY 17, 2017
SHIC FUNDED STUDY SUGGESTS POTENTIAL FOR PATHOGEN TRANSMISSION VIA FEED
WEDNESDAY, MAY 17, 2017
*** CWD, TSE, PRION, Cattle, Pigs, Sheep, and Humans aka Mad Cow Disease
WEDNESDAY, MAY 17, 2017
*** Chronic Wasting Disease CWD TSE Prion aka Mad Deer Disease and the Real Estate Market Land Values ***
Wednesday, May 24, 2017
PRION2017 CONFERENCE VIDEO UPDATE 23 – 26 May 2017 Edinburgh UPDATE 1
Terry S. Singeltary Sr.
posted by Terry S. Singeltary Sr. at
9:26 PM
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