Monday, April 25, 2016

Arkansas AGFC Phase 2 sampling reveals CWD positive deer in Madison and Pope counties

Phase 2 sampling reveals CWD positive deer in Madison and Pope counties

 

Date 04/25/2016 Description LITTLE ROCK – The Arkansas Game and Fish Commission has received confirmation that two additional deer have tested positive for chronic wasting disease in Arkansas. A deer in Madison County and another deer in Pope County were positive for the fatal disease. Both deer were road kills that were reported by the public.

 

The Madison County deer was a 2½-year-old doe found near Kingston and 2.9 miles west of the CWD focal area. The Pope County deer was a 2½-year-old buck found 44.4 miles south of the focal area near London.

 

The two positive samples came from a batch of 131 deer sent to the Wisconsin Veterinary Diagnostic Laboratory in Madison.

 

The first phase of chronic wasting disease sampling by the Arkansas Game and Fish Commission revealed a 23 percent prevalence rate in Newton and Boone counties. Of 266 randomly collected wild deer, 62 were found to have the fatal disease.

 

To determine the prevalence of the disease among deer, the AGFC took samples March 14-24 within a 125,000-acre, capsule-shaped area ranging from 5 miles west of Ponca to 5 miles east of Pruitt, and 10 miles across.

 

Including the sampled area, the AGFC has now received results of 84 animals with the disease. A total of 674 wild animals (645 white-tailed deer and 29 elk) have been sampled since laboratory results confirmed the disease Feb. 23, 2016. Eighty-one deer and three elk have been found to be positive.

 

Phase 2 of the sampling effort has focused on learning the spatial distribution of the disease, and includes statewide collection of sick or dead deer and elk. This phase of the sampling effort will continue through May 20.

 

The first case of CWD in Arkansas was found in a 2½-year-old female elk killed by a hunter Oct. 6 on the Buffalo National River near Pruitt during elk hunting season. It was the first animal in Arkansas confirmed to have CWD. Samples from the diseased female elk were first tested at the Wisconsin Veterinary Diagnostic Laboratory in Madison and verified by the National Veterinary Services Laboratories in Ames, Iowa, Feb. 23.

 

Anyone who sees a sick, dead or road-killed deer or elk should contact the AGFC’s radio room at 800-482-9262. Operators are available 24 hours per day, seven days per week. Reports will be sent to the appropriate person to collect samples.

 

Deer or elk infected with CWD tend to stay away from herds, may lose their fear of humans, walk in patterns, carry their head low, salivate excessively and grind their teeth. As the disease progresses, the animal will lose weight, develop an insatiable thirst and lose bodily functions.

 

The AGFC will hold a public meeting at 6 p.m., May 19, at Carroll Electric Cooperative, 511 E. Court St. in Jasper, to update the public on proposed hunting regulations.

 

Visit www.agfc.com/cwd for more information.

 


 

Tuesday, April 19, 2016

 

Arkansas First Phase of CWD sampling reveals 23 percent prevalence rate in focal area With 82 Confirmed to Date

 


 

 Friday, April 08, 2016

 

Arkansas AGFC Chronic Wasting Disease CWD TSE Prion Confirms 23 Additional Cases Total At 79 To Date

 


 

Friday, April 01, 2016

 

ARKANSAS CHRONIC WASTING DISEASE CWD TSE PRION CASES EXPLODE BY 27 NEW CASES WITH 50 CASES TOTAL TO DATE

 


 

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.

 

23

 

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.

 

31

 

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. ...

 


 

Friday, April 22, 2016

 

COLORADO CHRONIC WASTING DISEASE CWD TSE PRION SURVEILLANCE AND TESTING PROGRAM IS MINIMAL AND LIMITED

 


 

***These results suggest that cattle experimentally inoculated with CWD may have some limited amount of prion infectivity outside of the brain and spinal cord that may represent a previously unrecognized risk for transmission. 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.***

 

Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES

 

Title: Limited amplification of chronic wasting disease prions in the peripheral tissues of intracerebrally inoculated cattle Authors

 

item Haley, Nicholas - item Siepker, Christopher - item Greenlee, Justin item Richt, Jürgen -

 

Submitted to: Journal of General Virology Publication

 

Type: Peer Reviewed Journal Publication Acceptance

 

Date: March 30, 2016 Publication Date: N/A 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 use an in vitro amplification method called real time quaking induced conversion (RT-QuIC) to assess tissues from cattle inoculated with CWD for low levels of prions not detected by traditional diagnostic methods such as western blot and immunohistochemistry. This study reports that prions were identified by RT-QuIC only in cattle that were confirmed positive by traditional methods. However, prions were rarely identified in some peripheral tissues such as mesenteric lymph node, tonsil, or nasal turbinate that were not considered positive by traditional methods. These results suggest that cattle experimentally inoculated with CWD may have some limited amount of prion infectivity outside of the brain and spinal cord that may represent a previously unrecognized risk for transmission. 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: 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.

 


 

These results suggest that cattle experimentally inoculated with CWD may have some limited amount of prion infectivity outside of the brain and spinal cord that may represent a previously unrecognized risk for transmission. 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.

 

Scrapie transmits to white-tailed deer by the oral route and has a molecular profile similar to chronic wasting disease - (Abstract Only) - (12-Aug-15) Transmission of chronic wasting disease to sentinel reindeer (Rangifer tarandus tarandus) - (Abstract Only) - (12-Aug-15) Transmission of scrapie prions to primate after an extended silent incubation period - (Peer Reviewed Journal) 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. Transmission of the agent of sheep scrapie to deer results in PrPSc with two distinct molecular profiles - (Abstract Only) Greenlee, J., Moore, S.J., Smith, J.., West Greenlee, M.H., Kunkle, R. 2015. 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. Prion 2015. p. S62.

 

Monday, April 04, 2016

 

Limited amplification of chronic wasting disease prions in the peripheral tissues of intracerebrally inoculated cattle

 


 

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

 


 

2015 Report of the Committee on Wildlife Diseases Chronic Wasting Disease CWD TSE Prion

 

Chair: Colin Gillin, OR

 

Vice Chair: Peregrine Wolff, NV

 

Chronic Wasting Disease Research and Updates in Colorado

 

Michael Miller, Colorado Division of Parks and Wildlife

 

Dr. Michael Miller, Colorado Division of Parks and Wildlife, led a brief discussion on the implications of a recent study on chronic wasting disease (CWD) host range. The Case Western study results, presented at an international prion conference in May 2015, complement other efforts to assess human susceptibility to chronic wasting disease that have been ongoing since the mid-1990s. Findings from a variety of experimental & epidemiological studies support messaging since the mid-1990s that human illness resulting from CWD exposure appears unlikely. The new study’s results are consistent with other previous & contemporary data suggesting a low probability of human prion disease resulting from CWD exposure. Dr. Miller noted that even though human illness seems unlikely, minimizing the occurrence of CWD and encouraging other precautions for minimizing human exposure to CWD may be prudent. Trends observed in Colorado since 2002 suggest increasing infection rates in affected mule deer and elk herds, with the exception of one population unit intensively managed through harvest in the early 2000s. Controlling CWD will likely need to rely on hunting in order to remain politically, socially, and fiscally sustainable. Consequently, early intervention -- while infection rates are still low -- may offer the best opportunity to both suppress epidemics and minimize the likelihood of hunters harvesting infected animals. Dr. Miller suggested that the timing and approaches to CWD control may deserve more attention and reconsideration than given in recent years.

 

Summary of Recent Chronic Wasting Disease events in Texas Mitch Lockwood, Texas Parks and Wildlife Department

 

Bob Ditmar (TPWD), Andy Schwartz, Texas Animal Health Commission

 

Introduction:

 

• 3.9 million free-ranging white-tailed deer

 

• 700K white-tailed deer hunters

 

• 600K white-tailed deer harvested annually

 

• $3.6 billion economic output for all hunting

 

• $2.1 billion for deer hunting

 

• 1,300 deer breeding facilities

 

• > 110,000 deer in breeding facilities

 

• > 2,200 free-ranging deer moved annually through various permits

 

Texas Parks and Wildlife Department (TPWD) has been conducting CWD surveillance throughout the state since 2002. Biologists have collected more than 26,000 samples from hunter-harvested deer, and others have collected more than 21,000 samples in order to meet TPWD permitting requirements, totaling almost 48,000 samples. Additionally, Texas Animal Health Commission (TAHC) has maintained a Voluntary CWD Herd Certification Program since 1995. In 2012, CWD was discovered in 2 mule deer samples from far West Texas (Hueco Mountains) as a result of a targeted surveillance effort. This area is directly adjacent to a region in New Mexico with documented CWD occurrence. To date, five more positive samples have been obtained from this population through hunter harvested mule deer, indicating a disease prevalence of 10%.

 

Mule deer and white-tailed deer are regulated by TPWD, while other susceptible species (including elk) are regulated by the TAHC. This has generated the need for enhanced coordination and communication between these two agencies. The TPWD/TAHC CWD Management Plan was developed by both agencies in consultation with the state’s CWD Task Force. The Task Force is comprised of wildlife biologists, deer and elk breeders, veterinarians and other animal-health experts from TPWD, TAHC, Texas Veterinary Medical Diagnostic Laboratory, Texas Department of State Health Services, Texas A&M College of Veterinary Medicine, and USDA. The plan includes mandatory check stations for susceptible species taken inside the CWD Containment Zone, which covers portions of Hudspeth, Culberson, and El Paso counties. Artificial movement of deer is prohibited in the CWD Containment Zone.

 

On June 30, 2015 a sample from a Medina County (area on border of southern Edwards Plateau and northern South Texas Plains ecoregions) deer breeding facility was confirmed positive for CWD. The index breeding facility participated in TAHC’s voluntary CWD Herd Certification Program, and had tested 62 of 65 mortalities prior to June 2015 (60 not detected, 2 location results) since permitted in 2006. There were a total of 136 adult deer in the inventory on June 30, 2015, and the herd was considered to be relatively young.

 

During the previous 5 years, 107 deer were transferred from 30 deer breeding facilities into the index facility. During that same period, 835 were transferred from the index facility to 147 different facilities including 96 deer breeding facilities, 46 release sites, 3 DMP sites, and 2 sites in Mexico.

 

TPWD and TAHC immediately placed a temporary moratorium on movements of all captive deer in the state, and TAHC placed a Hold Order on the 177 “Tier 1” facilities. Since then, TPWD and TAHC worked with the CWD Task Force and industry stakeholders to develop a plan to lift the moratorium on deer transfers, which includes additional CWD testing requirements in deer breeding facilities or on registered release sites. Additionally, TAHC has removed the Hold Order for 120 facilities, leaving a total 57 facilities remaining under a Hold Order as of October 16, 2015. Most deer breeding facilities were authorized to transfer deer by August 24, 2015. Depopulation at the index facility was initiated in July 28 and completed on September 30, 2015. CWD was detected in a total of 4 (out of 136 adults) white-tailed deer in the index facility, all of which were 2-year-old bucks that were natural additions.

 

On September 15, 2015, CWD was confirmed in one of the trace-forward facilities, from which 84 deer had transferred out to 9 different facilities (5 deer breeding facilities, 3 release sites, and 1 nursing facility) since it received deer from the index herd. This resulted in 7 additional Hold Orders being issued by TAHC, 4 of which have since been released. The CWD-positive at the trace-forward facility was also a 2-year-old buck that was born in the index facility. In summary, CWD has been detected in a total of 5 captive white-tailed deer in Texas, 4 of which were located in the index facility, and 1 was located in a trace-forward facility. There are 36 deer from the 2-year-old cohort originating in the index facility that are reported to be alive in 7 deer breeding facilities, and possibly as many as 6 deer from that cohort still alive on release sites. Additionally, there are 33 deer that traced through the index facility that are still alive in 15 deer breeding facilities, and possibly as many as 51 trace-through deer are still alive on 24 different release sites, and 2 trace-through deer may still be alive in Mexico.

 

TPWD has intensified the statewide CWD surveillance efforts, with a goal to collect samples from more than 8,000 hunter-harvested deer, including 300 samples within a 5-mile radius of the index facility. TAHC will continue to pursue indemnity on exposed deer located in trace-forward facilities in an attempt to conduct a more thorough epidemiological investigation. TPWD and TAHC have committed to reevaluate movement qualification standards that apply to deer breeding facilities and release sites following the 2015-16 hunting season. Both agencies are exploring ante-mortem testing protocols, and will continue to seek guidance from experts in the field.

 

UPDATE

 

Friday, February 05, 2016

 

TEXAS NEW CHRONIC WASTING DISEASE CWD CASE DISCOVERD AT CAPTIVE DEER RELEASE SITE

 


 

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

 


 

Epidemiology of Recent CWD Cases in Ohio

 

Susan Skorupski, Assistant Director, USDA-APHIS-VS

 

Background

 

Ohio has had a voluntary Chronic Wasting Disease (CWD) Herd Certification Program for all cervidae for at least 12 years. Ohio has 331 cervidae herds in the CWD monitoring program with 256 at Certified level. In October 2012, Ohio White Tail Deer rule became effective. It includes several categories of white tail deer operations. Monitored Herds cannot sell or give away animals and includes hunting preserves. Under this rule, hunting preserves cannot move live animals from the premises and must annually sample 30 animals or 30% of harvested deer, based on the number of deer harvested during the previous year. Herds with Status are herds enrolled in the CWD Certification Program but not yet at certified level. Certified Status Herds are enrolled in the CWD monitoring program and have reached certified status. Ohio has 135 Monitored Herds, including 24 hunting preserves, 75 Herds with Status, and 256 Certified Status herds. Ohio’s approach to infected animals and associated animals and herds

 

Infected herd – herd where a CWD infected animal resided when the test positive sample was collected. Herd quarantined.

 

Exposed herd – any herd where an animal that tested CWD positive has resided within the 5 years before the CWD diagnosis. Whole herd quarantined Herd that contains an exposed animal – whole herd quarantined unless epidemiology information suggests the animal is of lower risk of spreading CWD.

 

Exposed animal – animal that was exposed to the CWD infected animal any time during the five years prior to when the animal died or was euthanized and sampled/tested positive for CWD.

 

Recent CWD history in Ohio

 

a.Pennsylvania traces

 

In the spring of 2014, Ohio received information on traces associated with CWD positive cases in Pennsylvania. Three Ohio herds were designated as Exposed herds because positive deer from infected herds in PA had been in the Ohio herd s during the previous 5 years. Fifty Ohio herds received 256 exposed deer from the 5 PA herds and 3 Ohio exposed herds. 85 of those animals were tested with Not Detected results in Ohio herds. 66 animals were traced to Out of State herds. That leaves 101 animals either standing in quarantined herds or not tested when they died or were harvested. 18 herds/preserves remain under quarantine.

 

b. First CWD positive found in Ohio

 

On October 22, 2014, National Veterinary Services Laboratory (NVSL) confirmed a CWD positive result for a 2.5 year old buck killed at a hunting preserve in Holmes County Ohio on October 2, 2014. The hunting preserve had been under quarantine since April 1, 2014 because of PA traces and was required to do 100% sampling of harvested deer. The positive animal had official identification tracing the animal to a CWD certified Pennsylvania herd. Records including a Certificate of Veterinary Inspection indicate the animal moved to Ohio March 13, 2013. Genetic testing was conducted to support the accuracy of the trace to the Pennsylvania herd. This herd was depopulated without indemnity April 27-29, 2015. 224 animals were depopulated at owner expense and sampled for CWD. All tests had Not Detected results for CWD. The premises was evaluated as a minimally contaminated facility. No cervidae have been added to the premises at this time.

 

The owner of the hunting preserve business also owns or is associated with breeding herds at other locations in Holmes County.

 

c. Second positive premises in Ohio

 

A white tail deer breeding herd owned by the same person who owned the CWD positive hunting preserve was designated as a positive herd in the spring of 2015. A CWD positive animal was sampled on 3/12/2015 and reported on March 25, 2015. The animal was a 5 year old whitetail doe purchased from a Wisconsin herd in February 2013. A second CWD positive animal was reported from this herd on May 22, 2015. This animal was a 1.5 year old natural addition doe. This herd was initially established in the fall of 2012 with the purchase of a CWD certified herd from the estate of a deceased owner. In the spring and fall of 2013, additional animals were added from at least 9 OH herds , 1 WI herd, 17 PA herds, and 3 IN herds. This herd had been quarantined since April 1,2014 because of traces from several CWD exposed or positive herds in Pennsylvania, including the herd that was the source of the CWD positive deer in the Ohio hunting preserve. It had received over 120 animals from these herds.

 

On June 15 and 16, this herd was depopulated with federal indemnity. Samples were collected for research purposes. 241 animals including 44 fawns were euthanized, sampled and tested. Sixteen additional positive were identified. They originated from 5 Ohio CWD certified herds and 4 Pennsylvania CWD certified herds. One of the Ohio herds was the herd that was used to initially establish this herd. One positive animal was over 60 months of age so that Ohio herd was not designated as an exposed herd. The other three Ohio herds were quarantined as exposed herds.

 

Records reviews identified 334 exposed animals associated with Ohio exposed herds. 42 Ohio herds containing these animals were quarantined. They have remained under quarantine until the quarantined animal(s) are euthanized and tested Not Detected for CWD or 60 months have passed since animals entered the herd. From Ohio Exposed Herd 1, 56 animals moved to 21 Ohio herds and 83 animals moved out of state. 27 animals were either already dead and tested with CWD Not Detected results or have since been tested with CWD Not Detected results. From Ohio Exposed Herd 2, 76 animals moved to 16 Ohio herds and 94 animals moved out of state. 25 animals were either already dead and tested with CWD Not Detected results or have since been tested with CWD Not Detected results. From Oho Exposed Herd 3, 21 animals moved to 5 Ohio herds and 4 animals moved out of state. 7 animals were either already dead and tested with CWD Not Detected results or have since been tested with CWD Not Detected results. Ohio received 2 exposed animals from the exposed herd in Pennsylvania associated with this case. In summary, 334 exposed animals were identified and traced to 40 Ohio herds. 59 of those in Ohio have been tested with Not Detected CWD results. 181 have been traced out of state and 94 are still standing in 26 quarantined herds/hunting preserves.

 

Ohio Exposed Herd 1 has been in the CWD Certification Program since September 2003 and has an inventory as of 48 head over 1 year old. Ohio Exposed Herd 2 has been in the CWD Certification Program since October 2003 and has an inventory of 93 animals. Ohio Exposed Herd 3 has been in the CWD Certification Program since February 2009 but started with a status date of May, 2001 and has an inventory of 17 deer.

 

In addition Ohio received reports of 72 exposed deer form OOS Exposed herds traced to 18 Ohio herds. 18 of those animals had moved to out of state herds. 30 animals were tested in Ohio with Not Detected results. 12 animals remain in 7 quarantined herds.

 

The summary of all traces associated with positive cases in Ohio and Pennsylvania in 2014 – 2015 are:

 

Total exposed animals traced to Ohio:661

 

Total tested Not Detected: 176

 

Total animals traced to Out of State Premises: 265

 

Total premises initially quarantined 87

 

Total premises remaining quarantined: 40

 

Total Hunting Preserves quarantined: 10

 

USDA Cervid Health Program Updates

 

Randy Pritchard, USDA, APHIS, Veterinary Services

 

Voluntary Chronic Wasting Disease (CWD) Herd Certification Program

 

The APHIS National CWD Herd Certification Program (HCP) was implemented in 2014. It is a voluntary Federal-State-industry cooperative program administered by APHIS and implemented by participating States. The program provides uniform national herd certification standards that minimize the risk of spreading CWD in farmed cervid populations. Participating States and herd owners must comply with requirements for animal identification, fencing, recordkeeping, inspections/inventories, as well as animal mortality testing and response to any CWD-exposed, suspect, and positive herds. APHIS monitors the Approved State HCPs to ensure consistency with Federal standards through annual reporting by the States. With each year of successful surveillance, participating herds will advance in status until reaching five years with no evidence of CWD, at which time herds are certified as being low-risk for CWD. Only captive cervids from enrolled herds certified as low risk for CWD may move interstate. Currently, 30 States participate in the voluntary CWD Herd Certification Program; 29 have Approved HCPs and one has Provisional Approved status. VS is working with the remaining State to transition it to Approved status. FY2015 marks the second year that Approved States have submitted their CWD HCP annual reports to APHIS. APHIS is currently reviewing these reports.

 

Review of CWD Program Standards

 

The CWD Program Standards provide clarification and guidance on how to meet CWD Herd Certification Program and interstate movement requirements. VS committed to an annual review of the Program Standards by representatives of the cervid industry and appropriate State and Federal agencies. VS planned to perform a review in FY2015; however, this did not occur due to the response to highly pathogenic avian influenza (HPAI). VS expects to conduct a review in FY2016.

 

CWD in Farmed and Wild Cervids

 

Retrospective Epidemiology of CWD in Farmed Cervids: In response to a 2014 USAHA Resolution, VS asked States to include a retrospective summary of the epidemiology of all positive herds with their annual HCP reports for FY2015. Unfortunately, the response to HPAI delayed completion of this summary. Five States reported information to date. A few States indicated that they did not have the resources to devote to this request. VS will continue to gather this data and to collect more comprehensive data in the future.

 

Summary of CWD detections. As of September 30, 2015, CWD has been confirmed in wild deer and elk in 21 U.S. States, and in farmed cervids in 16 States. In total, 23 States have identified CWD in wild and/or farmed cervids. CWD has been reported in 70 farmed cervid herds in the United States. Confirmation of the disease in 3 free-ranging, wild white-tailed deer in Michigan in 2015 marked the first report of CWD in the wild cervid population in this State. FY2015 CWD Detections in Farmed Cervids: In FY2015, CWD was identified in eight farmed cervid herds: one white-tailed deer breeding herd in Pennsylvania, one elk breeding herd in Utah (traced back from a hunting facility in Utah), one white-tailed deer (WTD) breeding herd and one WTD hunting preserve in Ohio (owned by the same producer), two WTD breeding herds in Wisconsin, one WTD and elk herd in Texas, and a second WTD herd in Texas (traced from the first positive herd in Texas). The positive animals in Utah, Ohio, and Texas represented the first reported cases of CWD in captive cervids in all three of these States.

 

White-Tailed Deer Breeding Herd, Pennsylvania: On October 6, 2014, the National Veterinary Services Laboratories (NVSL) confirmed CWD in a 6-year-old doe from a captive WTD breeding facility in Reynoldsville, Pennsylvania. The doe was euthanized and tested because she was classified as a CWD- exposed animal that had previously resided in two trace back exposed herds. This herd was assembled in 2013 through the purchase of 16 animals from other HCP-certified herds in Pennsylvania, and had been under quarantine for receiving exposed animals from a trace back exposed herd. The remaining herd of eight WTD was depopulated with Federal indemnity on February 18, 2015, and no additional positive animals were detected. USDA collected samples for research purposes.

 

Elk Breeding Herd, Utah: On December 23, 2014, NVSL confirmed CWD in 3-year-old captive elk. The elk had been at a hunting park located in northern Utah, where he had resided for approximately 3 weeks prior to being hunter killed. All hunter-killed animals at the hunt park are required to be tested for CWD, and this animal was sampled through routine surveillance. The elk was traced back to its herd of origin, and that facility was quarantined. The herd was assembled in 1999 with bulls, and later elk cows, that originated from Colorado. Historical testing records for the herd were unavailable. The remaining 70 elk were depopulated using Federal indemnity funds on March 3, 2015, and an additional 25 elk were confirmed as CWD-positive. USDA collected samples for research purposes.

 

White-Tailed Deer Hunting Preserve, Ohio: On October 22, 2014, NVSL confirmed CWD in a buck taken from a captive WTD deer hunting preserve in Ohio. This was the first time that CWD had been detected in Ohio. The preserve was tested as part of Ohio’s CWD monitoring program. The herd had been under quarantine since April 2014 because it was a trace-forward herd associated with a CWD-exposed herd in Pennsylvania. The positive animal was traced to its herd of origin, a captive WTD breeding herd in Pennsylvania, through DNA identity testing. On November 26, 2014, the Ohio State Veterinarian issued an Order of Destruction for animals on the hunting preserve. The State executed this Order on April 27-30, 2015. The herd of 224 WTD was depopulated and no other positives were detected. USDA did not provide Federal indemnity.

 

White-Tailed Deer Breeding Herd, Ohio: On March 31, 2015, NVSL confirmed CWD infection in a 5-year-old WTD doe from a captive breeding herd in Holmesville, Ohio. The index animal was received from a Wisconsin WTD farm in January 2013. The CWD-positive herd was owned by the same individual as the Ohio hunt preserve that was found to be CWD positive in October 2014. On May 22, 2015, NVSL confirmed a second positive case in the same herd -- a yearling WTD doe that was a natural addition in the same breeding herd. The herd had been under quarantine since April 1, 2014 due to epidemiological linkages with two WTD herds in Pennsylvania – one a positive herd and the other a traceback exposed herd. USDA provided Federal indemnity and depopulated this herd on June 15 and 16, 2015. USDA collected samples for research purposes. NVSL confirmed CWD in 16 additional animals in the herd. Of the 16 positives, one was natural addition and the rest were purchased additions. The positive animals were purchased from February 26, 2013 through September 24, 2013, except for one purchased in 2012. Eleven purchased additions traced-back to 3 herds in Pennsylvania and four purchased additions traced to three other herds in Ohio.

 

White-Tailed Deer Breeding Herd, Wisconsin: On October 6, 2014, NVSL confirmed CWD in a 2-year-old doe born in June of 2012 that died on a Richland County farm. The facility is within the CWD management zone in Wisconsin. The remaining 51 deer were euthanized on November 20, 2014, and seven additional positives (all males born in 2012) were found. Two of these 7 were purchased additions with the last added to the herd in January 2013. All sales from this herd were to shooting preserves. This premises was double fenced and had been compliant in a herd certification program for over 10 years.

 

White-Tailed Deer Breeding Herd, Wisconsin: On June 19, 2015, NVSL confirmed CWD in a 7-year-old female WTD from a breeding facility in Eau Claire County. The doe was a natural addition to this breeding herd. This is the first positive CWD case, captive or wild, in this county. The doe was found dead and was showing no clinical signs of CWD at the time of death. Since 2003, this herd has tested 391 animals for CWD and all had “not detected” results. In addition, 317 animals have tested “not detected” from the associated hunting preserve over the same time period. A second positive natural addition doe from this herd was confirmed positive by NVSL on September 10, 2015. Several escape episodes have occurred from this herd. The herd is currently under quarantine and plans are underway for depopulation with State indemnity.

 

White-Tailed Deer and Elk Breeding Herd, Texas: On June 30, 2015, NVSL confirmed CWD in a 2-year-old WTD buck from a captive WTD and elk breeding herd in Medina County, Texas, approximately 500 miles from previously reported positive free-ranging mule deer in far West Texas. This was the first time that the disease had been detected in farmed cervids in the State. The index buck was born on the premises and found dead on June 18, 2015. Over 40 high-risk deer (i.e., pen mates, dam, others) were euthanized and tested after the index case was found. The NVSL confirmed CWD infection in two of those deer. Interestingly, all three of the positive deer identified to date on this premises have the same AI sire. However, the significance of this finding is unclear. In the past 5 years, records indicate that 130 WTD from 33 facilities moved into the positive herd and 838 WTD moved out of the positive herd to 147 different herds. One positive WTD was found in one of these trace-out herds (see herd description below). Additionally, 23 elk were also moved from this herd to another herd in TX in 2014. All trace-outs have been intrastate except for movements to two premises in Mexico. Premises that have received deer from the index herd are under movement restrictions. VS is collaborating with animal health authorities in Mexico. VS paid indemnity and depopulated this herd on September 30, 2015, and no additional positive animals were detected. USDA collected samples for research purposes.

 

White-Tailed Deer Herd, Texas: On September 14, 2015 NVSL confirmed CWD from tissues from a WTD in Lavaca County, Texas. This animal was a traceout from the first CWD positive herd from June 30, 2015. Additional epidemiology is ongoing.

 


 


 

Poster 26

 

“Atypical” Chronic Wasting Disease in PRNP Genotype 225FF Mule Deer

 

Lisa Wolfe, Karen Fox, Michael Miller

 

Colorado Parks and Wildlife, Fort Collins, CO

 

Narrative: We compared mule deer (Odocoileus hemionus) of two different PRNP genotypes (225SS, 225FF) for susceptibility to chronic wasting disease (CWD) in the face of environmental exposure to infectivity. All three 225SS deer had immunohistochemistry (IHC)-positive tonsil biopsies by 710 days post exposure (dpe), developed classical clinical signs 723-1,200 dpe, and showed postmortem gross and microscopic pathology, enzyme-linked immunosorbent assay (ELISA) results, and IHC staining typical of prion disease in mule deer. In contrast, although all three 225FF deer also became infected, the two individuals surviving >720 dpe were consistently biopsy negative, developed more subtle clinical signs of chronic wasting disease, and died 924 or 1,783 dpe. 225FF deer were ELISA “suspect” postmortem but showed negative or equivocal IHC staining of lymphoid tissues; both clinically-affected 225FF deer had spongiform encephalopathy in the absence of IHC staining in brain tissue. The experimental cases resembled three cases encountered among five additional captive 225FF deer that were not part of our experiment but also succumbed to chronic wasting disease. In all of these cases of CWD in 225FF mule deer, clinical presentation was atypical, as were the IHC staining properties of the associated PRPCWD. Our findings suggest that the current gold standard of IHC testing for diagnosis of CWD is insensitive for detection of disease in 225FF deer.

 

Managing CWD in Farmed Cervids ◊

 

Nicholas J. Haley

 

Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS

 

Narrative: Chronic wasting disease (CWD) is an efficiently transmitted spongiform encephalopathy of cervids (e.g. deer, elk, and moose), and is the only known prion disease affecting both free-ranging wildlife and captive animals. The management of CWD in farmed cervids will require three avenues of research: 1) the development of a sensitive live animal test, 2) the discovery and implementation of a safe and effective vaccine strategy, and 3) with or without a vaccine, the identification and cultivation of CWD-resistant cervids. The antemortem detection of CWD and other prion diseases has proven difficult, due in part to difficulties in identifying an appropriate peripheral tissue specimen and complications with conventional test sensitivity. At present, biopsies of the recto-anal mucosalassociated lymphoid tissues (RAMALT) have shown promising sensitivity in various assays and are not impractical to collect in live animals. Nasal brush collections have likewise proven both sensitive and practical for identification of prion infections in humans, though in cervids both rectal biopsy and nasal brush collection sensitivity is critically dependent on stage of infection and genetic background. A blood test would be ideal; however rudimentary assays currently in development have yet to be evaluated blindly on naturally occurring populations or on a large scale. Vaccine development is currently underway at several institutions, though an effectively protective strategy has yet to be identified. Ultimately, genetic resistance to CWD may be a critical corner piece in the management of CWD in farmed cervids – an approach which has been used effectively to reduce the incidence of scrapie in sheep worldwide. By exploiting resistant PrP alleles in currently available white-tail and elk genetic pools, and searching various isolated populations for evidence of additional resistance mechanisms, a suitable approach to improving CWD resistance in farmed cervids may be identified. Our research has specifically sought to develop an antemortem test for CWD using amplification-based assays on collections from recent CWD depopulations, while additionally using these assays to model CWD resistance in cervid populations. Our findings from this research represent the early stages in the management and ultimately eradication of CWD in farmed deer and elk. ◊ USAHA Paper

 


 

LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$

 

*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***

 


 

PRION 2015 CONFERENCE FT. COLLINS CWD RISK FACTORS TO HUMANS

 

*** LATE-BREAKING ABSTRACTS PRION 2015 CONFERENCE ***

 

O18

 

Zoonotic Potential of CWD Prions

 

Liuting Qing1, Ignazio Cali1,2, Jue Yuan1, Shenghai Huang3, Diane Kofskey1, Pierluigi Gambetti1, Wenquan Zou1, Qingzhong Kong1 1Case Western Reserve University, Cleveland, Ohio, USA, 2Second University of Naples, Naples, Italy, 3Encore Health Resources, Houston, Texas, USA

 

*** These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.

 

==================

 

***These results indicate that the CWD prion has the potential to infect human CNS and peripheral lymphoid tissues and that there might be asymptomatic human carriers of CWD infection.***

 

==================

 

P.105: RT-QuIC models trans-species prion transmission

 

Kristen Davenport, Davin Henderson, Candace Mathiason, and Edward Hoover Prion Research Center; Colorado State University; Fort Collins, CO USA

 

Conversely, FSE maintained sufficient BSE characteristics to more efficiently convert bovine rPrP than feline rPrP. Additionally, human rPrP was competent for conversion by CWD and fCWD.

 

***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.

 

================

 

***This insinuates that, at the level of protein:protein interactions, the barrier preventing transmission of CWD to humans is less robust than previously estimated.***

 

================

 


 

*** PRICE OF CWD TSE PRION POKER GOES UP 2014 ***

 

Transmissible Spongiform Encephalopathy TSE PRION update January 2, 2014

 

*** chronic wasting disease, there was no absolute barrier to conversion of the human prion protein.

 

*** Furthermore, the form of human PrPres produced in this in vitro assay when seeded with CWD, resembles that found in the most common human prion disease, namely sCJD of the MM1 subtype.

 


 


 

*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***

 


 

*** The potential impact of prion diseases on human health was greatly magnified by the recognition that interspecies transfer of BSE to humans by beef ingestion resulted in vCJD. While changes in animal feed constituents and slaughter practices appear to have curtailed vCJD, there is concern that CWD of free-ranging deer and elk in the U.S. might also cross the species barrier. Thus, consuming venison could be a source of human prion disease. Whether BSE and CWD represent interspecies scrapie transfer or are newly arisen prion diseases is unknown. Therefore, the possibility of transmission of prion disease through other food animals cannot be ruled out. There is evidence that vCJD can be transmitted through blood transfusion. There is likely a pool of unknown size of asymptomatic individuals infected with vCJD, and there may be asymptomatic individuals infected with the CWD equivalent. These circumstances represent a potential threat to blood, blood products, and plasma supplies.

 


 

Chronic Wasting Disease and Potential Transmission to Humans

 

Ermias D. Belay,* Ryan A. Maddox,* Elizabeth S. Williams,† Michael W. Miller,‡ Pierluigi Gambetti,§ and Lawrence B. Schonberger*

 

Chronic wasting disease (CWD) of deer and elk is endemic in a tri-corner area of Colorado, Wyoming, and Nebraska, and new foci of CWD have been detected in other parts of the United States. Although detection in some areas may be related to increased surveillance, introduction of CWD due to translocation or natural migration of animals may account for some new foci of infection. Increasing spread of CWD has raised concerns about the potential for increasing human exposure to the CWD agent. The foodborne transmission of bovine spongiform encephalopathy to humans indicates that the species barrier may not completely protect humans from animal prion diseases. Conversion of human prion protein by CWDassociated prions has been demonstrated in an in vitro cellfree experiment, but limited investigations have not identified strong evidence for CWD transmission to humans. More epidemiologic and laboratory studies are needed to monitor the possibility of such transmissions.

 

Conclusions

 

The lack of evidence of a link between CWD transmission and unusual cases of CJD, despite several epidemiologic investigations, and the absence of an increase in CJD incidence in Colorado and Wyoming suggest that the risk, if any, of transmission of CWD to humans is low. Although the in vitro studies indicating inefficient conversion of human prion protein by CWD-associated prions raise the possibility of low-level transmission of CWD to humans, no human cases of prion disease with strong evidence of a link with CWD have been identified. However, the transmission of BSE to humans and the resulting vCJD indicate that, provided sufficient exposure, the species barrier may not completely protect humans from animal prion diseases. Because CWD has occurred in a limited geographic area for decades, an adequate number of people may not have been exposed to the CWD agent to result in a clinically recognizable human disease. The level and frequency of human exposure to the CWD agent may increase with the spread of CWD in the United States. Because the number of studies seeking evidence for CWD transmission to humans is limited, more epidemiologic and laboratory studies should be conducted to monitor the possibility of such transmissions. Studies involving transgenic mice expressing human and cervid prion protein are in progress to further assess the potential for the CWD agent to cause human disease. Epidemiologic studies have also been initiated to identify human cases of prion disease among persons with an increased risk for exposure to potentially CWD-infected deer or elk meat (47). If such cases are identified, laboratory data showing similarities of the etiologic agent to that of the CWD agent would strengthen the conclusion for a causal link. Surveillance for human prion diseases, particularly in areas where CWD has been detected, remains important to effectively monitor the possible transmission of CWD to humans. Because of the long incubation period associated with prion diseases, convincing negative results from epidemiologic and experimental laboratory studies would likely require years of follow-up. In the meantime, to minimize the risk for exposure to the CWD agent, hunters should consult with their state wildlife agencies to identify areas where CWD occurs and continue to follow advice provided by public health and wildlife agencies. Hunters should avoid eating meat from deer and elk that look sick or test positive for CWD. They should wear gloves when field-dressing carcasses, boneout the meat from the animal, and minimize handling of brain and spinal cord tissues. As a precaution, hunters should avoid eating deer and elk tissues known to harbor the CWD agent (e.g., brain, spinal cord, eyes, spleen, tonsils, lymph nodes) from areas where CWD has been identified.

 


 

now, let’s see what the authors said about this casual link, personal communications years ago. see where it is stated NO STRONG evidence. so, does this mean there IS casual evidence ???? “Our conclusion stating that we found no strong evidence of CWD transmission to humans”

 

From: TSS (216-119-163-189.ipset45.wt.net)

 

Subject: CWD aka MAD DEER/ELK TO HUMANS ???

 

Date: September 30, 2002 at 7:06 am PST

 

From: "Belay, Ermias"

 

To: Cc: "Race, Richard (NIH)" ; ; "Belay, Ermias"

 

Sent: Monday, September 30, 2002 9:22 AM

 

Subject: RE: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS

 

Dear Sir/Madam,

 

In the Archives of Neurology you quoted (the abstract of which was attached to your email), we did not say CWD in humans will present like variant CJD. That assumption would be wrong. I encourage you to read the whole article and call me if you have questions or need more clarification (phone: 404-639-3091). Also, we do not claim that "no-one has ever been infected with prion disease from eating venison." Our conclusion stating that we found no strong evidence of CWD transmission to humans in the article you quoted or in any other forum is limited to the patients we investigated.

 

Ermias Belay, M.D. Centers for Disease Control and Prevention

 

-----Original Message-----

 

From: Sent: Sunday, September 29, 2002 10:15 AM

 

To: rr26k@nih.gov; rrace@niaid.nih.gov; ebb8@CDC.GOV

 

Subject: TO CDC AND NIH - PUB MED- 3 MORE DEATHS - CWD - YOUNG HUNTERS

 

Sunday, November 10, 2002 6:26 PM ......snip........end..............TSS

 

Thursday, April 03, 2008

 

A prion disease of cervids: Chronic wasting disease 2008 1: Vet Res. 2008 Apr 3;39(4):41 A prion disease of cervids: Chronic wasting disease Sigurdson CJ.

 

snip...

 

*** twenty-seven CJD patients who regularly consumed venison were reported to the Surveillance Center***,

 

snip... full text ;

 


 

CJD is so rare in people under age 30, one case in a billion (leaving out medical mishaps), that four cases under 30 is "very high," says Colorado neurologist Bosque. "Then, if you add these other two from Wisconsin [cases in the newspaper], six cases of CJD in people associated with venison is very, very high." Only now, with Mary Riley, there are at least seven, and possibly eight, with Steve, her dining companion. "It's not critical mass that matters," however, Belay says. "One case would do it for me." The chance that two people who know each other would both contact CJD, like the two Wisconsin sportsmen, is so unlikely, experts say, it would happen only once in 140 years.

 

Given the incubation period for TSEs in humans, it may require another generation to write the final chapter on CWD in Wisconsin. "Does chronic wasting disease pass into humans? We'll be able to answer that in 2022," says Race. Meanwhile, the state has become part of an immense experiment.

 


 

I urge everyone to watch this video closely...terry

 

*** you can see video here and interview with Jeff's Mom, and scientist telling you to test everything and potential risk factors for humans ***

 


 

Envt.07:

 

Pathological Prion Protein (PrPTSE) in Skeletal Muscles of Farmed and Free Ranging White-Tailed Deer Infected with Chronic Wasting Disease

 

***The presence and seeding activity of PrPTSE in skeletal muscle from CWD-infected cervids suggests prevention of such tissue in the human diet as a precautionary measure for food safety, pending on further clarification of whether CWD may be transmissible to humans.

 


 

Prions in Skeletal Muscles of Deer with Chronic Wasting Disease Rachel C. Angers1,*, Shawn R. Browning1,*,†, Tanya S. Seward2, Christina J. Sigurdson4,‡, Michael W. Miller5, Edward A. Hoover4, Glenn C. Telling1,2,3,§ snip...

 

Abstract The emergence of chronic wasting disease (CWD) in deer and elk in an increasingly wide geographic area, as well as the interspecies transmission of bovine spongiform encephalopathy to humans in the form of variant Creutzfeldt Jakob disease, have raised concerns about the zoonotic potential of CWD. Because meat consumption is the most likely means of exposure, it is important to determine whether skeletal muscle of diseased cervids contains prion infectivity. Here bioassays in transgenic mice expressing cervid prion protein revealed the presence of infectious prions in skeletal muscles of CWD-infected deer, demonstrating that humans consuming or handling meat from CWD-infected deer are at risk to prion exposure.

 


 

***********CJD REPORT 1994 increased risk for consumption of veal and venison and lamb***********

 

CREUTZFELDT JAKOB DISEASE SURVEILLANCE IN THE UNITED KINGDOM THIRD ANNUAL REPORT AUGUST 1994

 

Consumption of venison and veal was much less widespread among both cases and controls. For both of these meats there was evidence of a trend with increasing frequency of consumption being associated with increasing risk of CJD. (not nvCJD, but sporadic CJD...tss)

 

These associations were largely unchanged when attention was restricted to pairs with data obtained from relatives. ...

 

Table 9 presents the results of an analysis of these data.

 

There is STRONG evidence of an association between ‘’regular’’ veal eating and risk of CJD (p = .0.01).

 

Individuals reported to eat veal on average at least once a year appear to be at 13 TIMES THE RISK of individuals who have never eaten veal.

 

There is, however, a very wide confidence interval around this estimate. There is no strong evidence that eating veal less than once per year is associated with increased risk of CJD (p = 0.51).

 

The association between venison eating and risk of CJD shows similar pattern, with regular venison eating associated with a 9 FOLD INCREASE IN RISK OF CJD (p = 0.04).

 

There is some evidence that risk of CJD INCREASES WITH INCREASING FREQUENCY OF LAMB EATING (p = 0.02).

 

The evidence for such an association between beef eating and CJD is weaker (p = 0.14). When only controls for whom a relative was interviewed are included, this evidence becomes a little STRONGER (p = 0.08).

 

snip...

 

It was found that when veal was included in the model with another exposure, the association between veal and CJD remained statistically significant (p = < 0.05 for all exposures), while the other exposures ceased to be statistically significant (p = > 0.05).

 

snip...

 

In conclusion, an analysis of dietary histories revealed statistical associations between various meats/animal products and INCREASED RISK OF CJD. When some account was taken of possible confounding, the association between VEAL EATING AND RISK OF CJD EMERGED AS THE STRONGEST OF THESE ASSOCIATIONS STATISTICALLY. ...

 

snip...

 

In the study in the USA, a range of foodstuffs were associated with an increased risk of CJD, including liver consumption which was associated with an apparent SIX-FOLD INCREASE IN THE RISK OF CJD. By comparing the data from 3 studies in relation to this particular dietary factor, the risk of liver consumption became non-significant with an odds ratio of 1.2 (PERSONAL COMMUNICATION, PROFESSOR A. HOFMAN. ERASMUS UNIVERSITY, ROTTERDAM). (???...TSS)

 

snip...see full report ;

 


 

CJD9/10022

 

October 1994

 

Mr R.N. Elmhirst Chairman British Deer Farmers Association Holly Lodge Spencers Lane BerksWell Coventry CV7 7BZ

 

Dear Mr Elmhirst,

 

CREUTZFELDT-JAKOB DISEASE (CJD) SURVEILLANCE UNIT REPORT

 

Thank you for your recent letter concerning the publication of the third annual report from the CJD Surveillance Unit. I am sorry that you are dissatisfied with the way in which this report was published.

 

The Surveillance Unit is a completely independant outside body and the Department of Health is committed to publishing their reports as soon as they become available. In the circumstances it is not the practice to circulate the report for comment since the findings of the report would not be amended. In future we can ensure that the British Deer Farmers Association receives a copy of the report in advance of publication.

 

The Chief Medical Officer has undertaken to keep the public fully informed of the results of any research in respect of CJD. This report was entirely the work of the unit and was produced completely independantly of the the Department.

 

The statistical results reqarding the consumption of venison was put into perspective in the body of the report and was not mentioned at all in the press release. Media attention regarding this report was low key but gave a realistic presentation of the statistical findings of the Unit. This approach to publication was successful in that consumption of venison was highlighted only once by the media ie. in the News at one television proqramme.

 

I believe that a further statement about the report, or indeed statistical links between CJD and consumption of venison, would increase, and quite possibly give damaging credence, to the whole issue. From the low key media reports of which I am aware it seems unlikely that venison consumption will suffer adversely, if at all.

 


 

*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***

 


 

O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations

 

Emmanuel Comoy, Jacqueline Mikol, Valerie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France

 

Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods.

 

*** We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period,

 

***with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold long incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014),

 

***is the third potentially zoonotic PD (with BSE and L-type BSE),

 

***thus questioning the origin of human sporadic cases. We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.

 

===============

 

***thus questioning the origin of human sporadic cases***

 

===============

 

***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.

 

==============

 


 

Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES

 

Title: Transmission of scrapie prions to primate after an extended silent incubation period

 

Authors

 

item Comoy, Emmanuel - item Mikol, Jacqueline - item Luccantoni-Freire, Sophie - item Correia, Evelyne - item Lescoutra-Etchegaray, Nathalie - item Durand, Valérie - item Dehen, Capucine - item Andreoletti, Olivier - item Casalone, Cristina - item Richt, Juergen item Greenlee, Justin item Baron, Thierry - item Benestad, Sylvie - item Hills, Bob - item Brown, Paul - item Deslys, Jean-Philippe -

 

Submitted to: Scientific Reports Publication Type: Peer Reviewed Journal Publication Acceptance Date: May 28, 2015 Publication Date: June 30, 2015 Citation: Comoy, E.E., Mikol, J., Luccantoni-Freire, S., Correia, E., Lescoutra-Etchegaray, N., Durand, V., Dehen, C., Andreoletti, O., Casalone, C., Richt, J.A., Greenlee, J.J., Baron, T., Benestad, S., Brown, P., Deslys, J. 2015. Transmission of scrapie prions to primate after an extended silent incubation period. Scientific Reports. 5:11573.

 

Interpretive Summary: The transmissible spongiform encephalopathies (also called prion diseases) are fatal neurodegenerative diseases that affect animals and humans. The agent of prion diseases is a misfolded form of the prion protein that is resistant to breakdown by the host cells. Since all mammals express prion protein on the surface of various cells such as neurons, all mammals are, in theory, capable of replicating prion diseases. One example of a prion disease, bovine spongiform encephalopathy (BSE; also called mad cow disease), has been shown to infect cattle, sheep, exotic undulates, cats, non-human primates, and humans when the new host is exposed to feeds or foods contaminated with the disease agent. The purpose of this study was to test whether non-human primates (cynomologous macaque) are susceptible to the agent of sheep scrapie. After an incubation period of approximately 10 years a macaque developed progressive clinical signs suggestive of neurologic disease. Upon postmortem examination and microscopic examination of tissues, there was a widespread distribution of lesions consistent with a transmissible spongiform encephalopathy. This information will have a scientific impact since it is the first study that demonstrates the transmission of scrapie to a non-human primate with a close genetic relationship to humans. This information is especially useful to regulatory officials and those involved with risk assessment of the potential transmission of animal prion diseases to humans. Technical Abstract: Classical bovine spongiform encephalopathy (c-BSE) is an animal prion disease that also causes variant Creutzfeldt-Jakob disease in humans. Over the past decades, c-BSE's zoonotic potential has been the driving force in establishing extensive protective measures for animal and human health.

 

*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.

 

*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.

 

*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.

 


 

why do we not want to do TSE transmission studies on chimpanzees $

 

5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.

 

snip...

 

R. BRADLEY

 


 

”The occurrence of CWD must be viewed against the contest of the locations in which it occurred. It was an incidental and unwelcome complication of the respective wildlife research programmes. Despite it’s subsequent recognition as a new disease of cervids, therefore justifying direct investigation, no specific research funding was forthcoming. The USDA veiwed it as a wildlife problem and consequently not their province!” page 26.

 


 

In Confidence - Perceptions of unconventional slow virus diseases of animals in the USA - APRIL-MAY 1989 - G A H Wells

 

3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs. ...

 


 

Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.

 

snip...

 

The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...

 


 


 


 

LOOKING FOR CWD IN HUMANS AS nvCJD or as an ATYPICAL CJD, LOOKING IN ALL THE WRONG PLACES $$$

 

*** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***

 


 

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 ;

 


 

Monday, November 3, 2014

 

Persistence of ovine scrapie infectivity in a farm environment following cleaning and decontamination

 


 

PL1

 

Using in vitro prion replication for high sensitive detection of prions and prionlike proteins and for understanding mechanisms of transmission.

 

Claudio Soto

 

Mitchell Center for Alzheimer's diseases and related Brain disorders, Department of Neurology, University of Texas Medical School at Houston.

 

Prion and prion-like proteins are misfolded protein aggregates with the ability to selfpropagate to spread disease between cells, organs and in some cases across individuals. I n T r a n s m i s s i b l e s p o n g i f o r m encephalopathies (TSEs), prions are mostly composed by a misfolded form of the prion protein (PrPSc), which propagates by transmitting its misfolding to the normal prion protein (PrPC). The availability of a procedure to replicate prions in the laboratory may be important to study the mechanism of prion and prion-like spreading and to develop high sensitive detection of small quantities of misfolded proteins in biological fluids, tissues and environmental samples. Protein Misfolding Cyclic Amplification (PMCA) is a simple, fast and efficient methodology to mimic prion replication in the test tube. PMCA is a platform technology that may enable amplification of any prion-like misfolded protein aggregating through a seeding/nucleation process. In TSEs, PMCA is able to detect the equivalent of one single molecule of infectious PrPSc and propagate prions that maintain high infectivity, strain properties and species specificity. Using PMCA we have been able to detect PrPSc in blood and urine of experimentally infected animals and humans affected by vCJD with high sensitivity and specificity. Recently, we have expanded the principles of PMCA to amplify amyloid-beta (Aβ) and alphasynuclein (α-syn) aggregates implicated in Alzheimer's and Parkinson's diseases, respectively. Experiments are ongoing to study the utility of this technology to detect Aβ and α-syn aggregates in samples of CSF and blood from patients affected by these diseases.

 

=========================

 

***Recently, we have been using PMCA to study the role of environmental prion contamination on the horizontal spreading of TSEs. These experiments have focused on the study of the interaction of prions with plants and environmentally relevant surfaces. Our results show that plants (both leaves and roots) bind tightly to prions present in brain extracts and excreta (urine and feces) and retain even small quantities of PrPSc for long periods of time. Strikingly, ingestion of prioncontaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate. Furthermore, plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety of 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 ;

 

Potential role of soil properties in the spread of CWD in western Canada

 

Alsu Kuznetsova, Debbie McKenzie, Pamela Banser, Tariq Siddique & Judd M. Aiken

 


 

Estimating Prion Adsorption Capacity of Soil by BioAssay of Subtracted Infectivity from Complex Solutions (BASICS)

 

Estimating Prion Adsorption Capacity of Soil by BioAssay of Subtracted Infectivity from Complex Solutions (BASICS) A. Christy Wyckoff, Krista L. Lockwood, Crystal Meyerett-Reid, Brady A. Michel, Heather Bender, Kurt C. VerCauteren, Mark D. Zabel PLOS x Published: March 4, 2013 http://dx.doi.org/10.1371/journal.pone.0058630

 


 

Behavior of Prions in the Environment: Implications for Prion Biology

 

Shannon L. Bartelt-Hunt1*, Jason C. Bartz2*

 


 

Prion Amplification and Hierarchical Bayesian Modeling Refine Detection of Prion Infection

 

A. Christy Wyckoff1, 2 n1 , Nathan Galloway3 n1 , Crystal Meyerett-Reid1 , Jenny Powers4 , Terry Spraker1 , Ryan J. Monello4 , Bruce Pulford1 , Margaret Wild4 , Michael Antolin3 , Kurt VerCauteren2 […] & Mark Zabel1 - Show fewer authors Scientific Reports 5, Article number: 8358 (2015) doi:10.1038/srep08358 Download Citation

 

Molecular ecology Proteins Statistics Received: 27 June 2014

 


 

CELL REPORTS

 

Report

 

Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions

 


 

PRION UPDATE VIA VEGETABLE PLANTS FROM THE SOIL

 

56. Members considered that there is no evidence that crops grown on the land which received composted excreta from BSE-challenged animals pose a TSE risk to humans or animals. One member suggested that, as some of these animals are orally challenged with high doses of BSE-infected materials, and the distribution of infectivity in the digestive system is not completely understood, it might be premature to conclude that there is no infective agent in the manure.

 

Furthermore, an unpublished study had indicated low level absorption of PrP from soil by tomato plants although it should be noted that this study had not been repeated. Details of this work would be sent to the SEAC Secretary. Dr Matthews explained that most of the manure from animals challenged with high doses of BSE had already been composted and used for coppicing. Members agreed that the risks from disposal of residual manure from experimental animals would be much less than historic risks of on farm contamination from naturally infected animals at the height of the BSE epidemic. ...SNIP...END

 


 

SRM are certain cattle tissues capable of transmitting BSE. There is no human health risk assessment to indicate the absence of human health concerns associated with use of composted SRM domestically. To date, scientific evidence has not been able to demonstrate that composting destroys prions. Although domestic use would pose a negligible risk to livestock, there is a potential risk to humans via direct ingestion of the compost or of compost particles adhered to skin or plant material (e.g. carrots). Another potential route of exposure is by ingestion of prions that have been taken up by plants. It has been proven that bacteria are readily taken up by some plants (e.g. E. coli in lettuce) thus the uptake of prions by plants cannot be precluded or dismissed at this time. As a science-based regulator, the CFIA cannot change the policy on this issue without a risk assessment demonstrating that the use of composted SRM poses an acceptable risk to humans.

 


 

The BSE Inquiry / Statement No 19B (supplementary) Dr Alan Colchester Issued 06/08/1999 (not scheduled to give oral evidence) SECOND STATEMENT TO THE BSE INQUIRY Dr A Colchester BA BM BCh PhD FRCP Reader in Neurosciences & Computing, University of Kent at Canterbury; Consultant Neurologist, Guy’s Hospital London and William Harvey Hospital Ashford April 1999

 

snip...

 

88. Natural decay: Infectivity persists for a long time in the environment. A study by Palsson in 1979 showed how scrapie was contracted by healthy sheep, after they had grazed on land which had previously been grazed by scrapie-infected sheep, even though the land had lain fallow for three years before the healthy sheep were introduced. Brown also quoted an early experiment of his own (1991), where he had buried scrapie-infected hamster brain and found that he could still detect substantial infectivity three years later near where the material had been placed. 89. Potential environmental routes of infection: Brown discusses the various possible scenarios, including surface or subsurface deposits of TSE-contaminated material, which would lead to a build-up of long-lasting infectivity. Birds feeding on animal remains (such as gulls visiting landfill sites) could disperse infectivity. Other animals could become vectors if they later grazed on contaminated land. "A further question concerns the risk of contamination of the surrounding water table or even surface water channels, by effluents and discarded solid wastes from treatment plants. A reasonable conclusion is that there is a potential for human infection to result from environmental contamination by BSE-infected tissue residues. The potential cannot be quantified because of the huge numbers of uncertainties and assumptions that attend each stage of the disposal process". These comments, from a long established authority on TSEs, closely echo my own statements which were based on a recent examination of all the evidence. 90. Susceptibility: It is likely that transmissibility of the disease to humans in vivo is probably low, because sheep that die from scrapie and cattle that die from BSE are probably a small fraction of the exposed population. However, no definitive data are available.

 

91. Recommendations for disposal procedures: Brown recommends that material which is actually or potentially contaminated by BSE should be: 1) exposed to caustic soda; 2) thoroughly incinerated under carefully inspected conditions; and 3) that any residue should be buried in landfill, to a depth which would minimise any subsequent animal or human exposure, in areas that would not intersect with any potable water-table source.

 

92. This review and recommendations from Brown have particular importance. Brown is one of the world's foremost authorities on TSEs and is a senior researcher in the US National Institutes of Health (NIH). It is notable that such a respected authority is forthright in acknowledging the existence of potential risks, and in identifying the appropriate measures necessary to safeguard public health. Paper by SM Cousens, L Linsell, PG Smith, Dr M Chandrakumar, JW Wilesmith, RSG Knight, M Zeidler, G Stewart, RG Will, "Geographical distribution of variant CJD in the UK (excluding Northern Ireland)". Lancet 353:18-21, 2 nd January 1999 93. The above paper {Appendix 41 (02/01/99)} (J/L/353/18) examined the possibility that patients with vCJD (variant CJD) might live closer to rendering factories than would be expected by chance. All 26 cases of vCJD in the UK with onset up to 31 st August 1998 were studied. The incubation period of vCJD is not known but by analogy with other human TSEs could lie within the range 5-25 years. If vCJD had arisen by exposure to rendering products, such exposure might plausibly have occurred 8-10 years before the onset of symptoms. The authors were able to obtain the addresses of all rendering plants in the UK which were in production in 1988. For each case of vCJD, the distance from the place of residence on 1st January 1998 to the nearest rendering plant was calculated

 

snip...

 


 

Friday, February 08, 2013

 

*** Behavior of Prions in the Environment: Implications for Prion Biology

 


 


 

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 ***

 


 

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.

 


 

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

 


 

Saturday, January 31, 2015

 

European red deer (Cervus elaphus elaphus) are susceptible to Bovine Spongiform Encephalopathy BSE by Oral Alimentary route

 


 


 

I strenuously once again urge the FDA and its industry constituents, to make it MANDATORY that all ruminant feed be banned to all ruminants, and this should include all cervids as soon as possible for the following reasons...

 

======

 

In the USA, under the Food and Drug Administrations BSE Feed Regulation (21 CFR 589.2000) most material (exceptions include milk, tallow, and gelatin) from deer and elk is prohibited for use in feed for ruminant animals. With regards to feed for non-ruminant animals, under FDA law, CWD positive deer may not be used for any animal feed or feed ingredients. For elk and deer considered at high risk for CWD, the FDA recommends that these animals do not enter the animal feed system.

 

***However, this recommendation is guidance and not a requirement by law.

 

======

 

31 Jan 2015 at 20:14 GMT

 

*** Ruminant feed ban for cervids in the United States? ***

 

31 Jan 2015 at 20:14 GMT

 

see Singeltary comment ;

 


 

Monday, March 28, 2016

 

National Scrapie Eradication Program February 2016 Monthly Report

 


 

Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission

 

Greetings again FDA and Mr. Pritchett et al,

 

I would kindly like to comment on ;

 

Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission

 

#158

 

Guidance for Industry

 

Use of Material from Deer and Elk in Animal Feed

 

This version of the guidance replaces the version made available September15, 2003.

 

This document has been revised to update the docket number, contact information, and standard disclosures. Submit comments on this guidance at any time.

 

Submit electronic comments to http://www.regulations.gov. Submit written comments to the Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852. All comments should be identified with the Docket No. FDA-2003-D-0432 (formerly 03D-0186).

 

For further information regarding this guidance, contact Burt Pritchett, Center for Veterinary Medicine (HFV-222), Food and Drug Administration, 7519 Standish Place, Rockville, MD 20855, 240-402-6276, E-mail: burt.pritchett@fda.hhs.gov.

 

Additional copies of this guidance document may be requested from the Policy and Regulations Staff (HFV-6), Center for Veterinary Medicine, Food and Drug Administration, 7519 Standish Place, Rockville, MD 20855, and may be viewed on the Internet at either http://www.fda.gov/AnimalVeterinary/default.htm or http://www.regulations.gov.

 

U.S. Department of Health and Human Services Food and Drug Administration Center for Veterinary Medicine March 2016

 

Contains Nonbinding Recommendations

 

2

 

Guidance for Industry Use of Material from Deer and Elk in Animal Feed

 

This guidance represents the current thinking of the Food and Drug Administration (FDA or Agency) on this topic. It does not establish any rights for any person and is not binding on FDA or the public. You can use an alternative approach if it satisfies the requirements of the applicable statutes and regulations. To discuss an alternative approach, contact the FDA office responsible for this guidance as listed on the title page.

 

I. Introduction

 

Under FDA’s BSE feed regulation (21 CFR 589.2000) most material from deer and elk is prohibited for use in feed for ruminant animals. This guidance document describes FDA’s recommendations regarding the use in all animal feed of all material from deer and elk that are positive for Chronic Wasting Disease (CWD) or are considered at high risk for CWD. The potential risks from CWD to humans or non-cervid animals such as poultry and swine are not well understood. However, because of recent recognition that CWD is spreading rapidly in white-tailed deer, and because CWD’s route of transmission is poorly understood, FDA is making recommendations regarding the use in animal feed of rendered materials from deer and elk that are CWD-positive or that are at high risk for CWD.

 

In general, FDA’s guidance documents do not establish legally enforceable responsibilities. Instead, guidances describe the Agency’s current thinking on a topic and should be viewed only as recommendations, unless specific regulatory or statutory requirements are cited. The use of the word should in Agency guidances means that something is suggested or recommended, but not required.

 

II. Background

 

CWD is a neurological (brain) disease of farmed and wild deer and elk that belong in the animal family cervidae (cervids). Only deer and elk are known to be susceptible to CWD by natural transmission. The disease has been found in farmed and wild mule deer, white-tailed deer, North American elk, and in farmed black-tailed deer. CWD belongs to a family of animal and human diseases called transmissible spongiform encephalopathies (TSEs). These include bovine spongiform encephalopathy (BSE or “mad cow” disease) in cattle; scrapie in sheep and goats; and classical and variant Creutzfeldt-Jakob diseases (CJD and vCJD) in humans. There is no known treatment for these diseases, and there is no vaccine to prevent them. In addition, although validated postmortem diagnostic tests are available, there are no validated diagnostic tests for CWD that can be used to test for the disease in live animals.

 

Contains Nonbinding Recommendations

 

III. Use in animal feed of material from CWD-positive deer and elk

 

Material from CWD-positive animals may not be used in any animal feed or feed ingredients. Pursuant to Sec. 402(a)(5) of the Federal Food, Drug, and Cosmetic Act, animal feed and feed ingredients containing material from a CWD-positive animal would be considered adulterated. FDA recommends that any such adulterated feed or feed ingredients be recalled or otherwise removed from the marketplace.

 

IV. Use in animal feed of material from deer and elk considered at high risk for CWD Deer and elk considered at high risk for CWD include: (1) animals from areas declared by State officials to be endemic for CWD and/or to be CWD eradication zones; and (2) deer and elk that at some time during the 60-month period immediately before the time of slaughter were in a captive herd that contained a CWD-positive animal.

 

FDA recommends that materials from deer and elk considered at high risk for CWD no longer be entered into the animal feed system. Under present circumstances, FDA is not recommending that feed made from deer and elk from a non-endemic area be recalled if a State later declares the area endemic for CWD or a CWD eradication zone. In addition, at this time, FDA is not recommending that feed made from deer and elk believed to be from a captive herd that contained no CWD-positive animals be recalled if that herd is subsequently found to contain a CWD-positive animal.

 

V. Use in animal feed of material from deer and elk NOT considered at high risk for CWD FDA continues to consider materials from deer and elk NOT considered at high risk for CWD to be acceptable for use in NON-RUMINANT animal feeds in accordance with current agency regulations, 21 CFR 589.2000. Deer and elk not considered at high risk include: (1) deer and elk from areas not declared by State officials to be endemic for CWD and/or to be CWD eradication zones; and (2) deer and elk that were not at some time during the 60-month period immediately before the time of slaughter in a captive herd that contained a CWD-positive animal.

 

3

 


 

Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission

 

Greetings again FDA and Mr. Pritchett et al,

 

MY comments and source reference of sound science on this very important issue are as follows ;

 

Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed Singeltary Submission

 

I kindly wish to once again submit to Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed.

 

Thank you kindly for allowing me to comment again, ...and again...and again, on a topic so important, why it is ‘NON-BINDING’ is beyond me.

 

this should have been finalized and made ‘BINDING’ or MANDATORY OVER A DECADE AGO.

 

but here lay the problem, once made ‘BINDING’ or ‘MANDATORY’, it is still nothing but ink on paper.

 

we have had a mad cow feed ban in place since August 1997, and since then, literally 100s of millions of pounds BANNED MAD COW FEED has been sent out to commerce and fed out (see reference materials).

 

ENFORCEMENT OF SAID BINDING REGULATIONS HAS FAILED US TOO MANY TIMES.

 

so, in my opinion, any non-binding or voluntary regulations will not work, and to state further, ‘BINDING’ or MANDATORY regulations will not work unless enforced.

 

with that said, we know that Chronic Wasting Disease CWD TSE Prion easily transmits to other cervid through the oral route.

 

the old transmission studies of BSE TSE floored scientist once they figured out what they had, and please don’t forget about those mink that were fed 95%+ dead stock downer cow, that all came down with TME. please see ;

 

It is clear that the designing scientists must also have shared Mr Bradleys surprise at the results because all the dose levels right down to 1 gram triggered infection.

 


 

it is clear that the designing scientists must have also shared Mr Bradleys surprise at the results because all the dose levels right down to 1 gram triggered infection.

 


 

Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle

 

Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME.

 

snip...

 

The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...

 


 

*** PLEASE SEE THIS URGENT UPDATE ON CWD AND FEED ANIMAL PROTEIN ***

 

Sunday, March 20, 2016

 

Docket No. FDA-2003-D-0432 (formerly 03D-0186) Use of Material from Deer and Elk in Animal Feed ***UPDATED MARCH 2016*** Singeltary Submission

 


 


 

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

 


 

Comment from Terry S. Singeltary Sr. Return to Docket Folder Summary This is a Comment on the Food and Drug Administration (FDA) Notice: Risk Assessment of Foodborne Illness Associated With Pathogens From Produce Grown in Fields Amended With Untreated Biological Soil Amendments of Animal Origin; Request for Scientific Data, Information, and Comments

 

For related information, Open Docket Folder Docket folder icon

 

--------------------------------------------------------------------------------

 

Show agency attachment(s) AttachmentsView All (0)

 

--------------------------------------------------------------------------------

 

Comment View document:Greetings FDA et al, I kindly would like to make comment submission to ;

 

Docket No. FDA-2016-N-0321 Risk Assessment of Foodborne Illness Associated with Pathogens from Produce Grown in Fields Amended with Untreated Biological Soil Amendments of Animal Origin; Request for Comments, Scientific Data, and Information

 

A Notice by the Food and Drug Administration on 03/04/2016

 

MY comment as follows,

 

There has been proven documented risk for Untreated Biological Soil Amendments of Animal Origin and risk of transmitting Transmissible Spongiform Encephalopathy TSE Prion disease aka mad cow type disease such as the typical and atypical Bovine Spongiform Encephalopathy strains, typical and atypical Scrapie strains, typical and atypical Chronic Wasting Disease CWD strains, and even the Transmissible Mink Encephalopathy TME Prion disease.

 

Science has 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.

 

Ingestion of prion contaminated 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.

 

Plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves) [please see data from Soto et al Prion2015 Conference below in Science reference data].

 

Also, Detection of protease-resistant cervid prion protein in water from a CWD-endemic area is very concerning.

 

Science has shown that soil plays a role in the spreading and transmission of the CWD and Scrapie TSE prion agent.

 

For these reason and more (see reference materials) I urge the FDA to stop this practice of Untreated Biological Soil Amendments of Animal Origin, including blood, for use on our produce grown in fields, for the following reasons,

 

please see attachments and updated TSE Prion science on these very important matters here (I do not advertise or make money the science is there for educational use for Transmissible Spongiform Encephalopathy TSE Prion disease.

 

just made a promise to mom dod 12/14/97 confirmed Heidenhain Variant Creutzfeldt Jakob Disease, hvCJD. ... AttachmentsView All (1) Comment from Terry S Singeltary Sr View Attachment:

 


 


 

Tuesday, March 15, 2016

 

Docket No. FDA-2016-N-0321 Risk Assessment of Foodborne Illness Associated with Pathogens from Produce Grown in Fields Amended with Untreated Biological Soil Amendments of Animal Origin; Request for Comments, Scientific Data, and Information Singeltary Submission

 


 

 Friday, April 22, 2016

 

*** Texas Scrapie Confirmed in a Hartley County Sheep where CWD was detected in a Mule Deer ***

 


 

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, 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 ?

 


 

Tuesday, April 12, 2016

 

The first detection of Chronic Wasting Disease (CWD) in Europe

 


 

Thursday, March 31, 2016

 

*** Chronic Wasting Disease CWD TSE Prion Roundup USA 2016 ***

 


 

Terry S. Singeltary Sr.

0 Comments:

Post a Comment

Subscribe to Post Comments [Atom]

<< Home