Download the full Chronic Wasting Disease and Cervidae Regulations in North America. [PDF]
Download a quick reference map of Rules Governing Interstate Transport of High-risk White-tailed Deer Carcass Parts [PDF].
The number one objective in the management of CWD is to prevent its spread into new areas. One theoretical mode of disease transmission is via infected carcasses. Therefore, in an effort to minimize the risk of disease spread, a number of states have adopted regulations affecting the transportation of hunter-harvested deer and elk.
Since the suspected infective agent (prion) is concentrated in the brain, spinal cord and lymph glands, the most common regulation is the prohibition of the importation of whole carcasses harvested from CWD areas. Some states, like Colorado, also have established regulations addressing the transport of deer and elk out of CWD areas. Generally, states that have adopted carcass transportation regulations do not allow the importation of any brain or spinal column tissue and allow transport of only the following:
A summary of state-by-state carcass transportation regulations is provided in Column J of the regulations on each state page (accessible from the home page) or on the map. Since these regulations are continually evolving, it is recommended that before hunting you check the CWD regulations in your home state, the state in which you will be hunting and states in which you will travel through en route home from your hunting area. Most state wildlife agencies provide regulations information on their websites, and may be accessed via the clickable map on the home page.
The Carcass Transport and Disposal Working Group of the Association of Fish and Wildlife Agencies (AFWA) Fish and Wildlife Health Committee developed the following guidelines for regulatory and non-regulatory approaches to carcass transport and disposal. The intent of the working group is to encourage states to adopt policies that minimize risk; do not hinder hunting, wild cervid population management, or disease control; are easily understood; and promote compliance because they are consistent and well-justified. The recommendations are based on current knowledge of CWD and may be updated when new information becomes available. The Working Group recognizes state wildlife management agencies will tailor their approach to fit individual concerns and situations, and asks that agency directors, through AFWA, give serious and urgent consideration to this matter so that this potential risk of CWD spread can be minimized.
Senate Environment and Public Works Subcommittee on Fisheries, Wildlife and Water
April 6, 2004
U.S. House of Representatives
House Resources Committee
Subcommittees on Forests and Forest Health, and
Fisheries Conservation, Wildlife and Oceans
Thursday, June 19, 2003
To establish a National Chronic Wasting Disease Task Force, and for other purposes.
HR2431 Word document
To amend the Fish and Wildlife Coordination Act to coordinate and strengthen scientific research and monitoring, and to promote public outreach, education, and awareness, of Chronic Wasting Disease affecting free-ranging populations of deer and elk, and for other purposes.
HR2430 Word document
To authorize the Secretary of the Interior to make grants to State and tribal governments to assist State and tribal efforts to manage and control the spread of chronic wasting disease in deer and elk herds, and for other purposes.
S1366 PDF document | Word document
To authorize the Secretary of the Interior to make grants to State and tribal governments to assist State and tribal efforts to manage and control the spread of chronic wasting disease in deer and elk herds, and for other purposes.
HR2636 PDF document | Word document
24 organizations sign letter requesting funding for National CWD Plan- April 18, 2003
Letter Word document
U.S. House of Representatives
House Resources Committee
Subcommittees on Forests and Forest Health, and
Fisheries Conservation, Wildlife and Oceans
May 16, 2002
CWD Alliances’ Testimony PDF document | Word document
An e-book is now available on the CWD Alliance website. The emphasis of this e-book is on modeling approaches to describe and gain insight of the spatial epidemiology of CWD.
Contributing Authors: Mary M. Conner – Utah Division of Wildlife Resources John E. Gross – National Park Service Paul C. Cross – United States Geological Survey Michael R. Ebinger – Utah State University Robert R. Gillies – Utah State University Michael D. Samuel – United States Geological Survey Michael W. Miller – Colorado Division of Wildlife
CWD Update 86 May 3, 2007
State and Provincial Updates
Lloyd Fox, Kansas Department of Wildlife & Parks provides the following: Kansas Dept. Wildlife and Parks has collected 10,737 samples for CWD testing since 1996. The only known positive cases of CWD in Kansas occurred in November 2001 at a captive elk facility and in December 2005 from an adult female white-tailed deer killed by a hunter in Cheyenne County. Usable tissues were obtained from 2,970 animals during 2006 and the recent hunting seasons. CWD prions were not detected from any of those samples. The species breakdown for the sample was 2,724 white-tailed deer, 225 mule deer, 15 elk, and 6 animals where the species was not recorded. The majority of the specimens were obtained from animals killed by hunters (n = 2,342 plus n = 400 on animals killed by hunters and taken to taxidermists). Animals killed by vehicles accounted for 185 specimens, while 28 specimens were collected from animals considered CWD suspects. Other source types, such as animals confiscated for law enforcement purposes, accounted for the remaining 15 specimens. For more information on CWD in Kansas, phone Ruby Mosher at 620-342-0658 or email her at email@example.com. Kansas Department of Wildlife & Parks press release is available at: kdwp.state.ks.us/news/kdwp_info/news/weekly_news/4_26_07/chronic_wasting_disease_not_found_in_2006_deer_season.
John Major, New York Department of Environmental Conservation (DEC), provides the following: In New York State, efforts continued with CWD surveillance through sampling of hunter killed deer statewide and mandatory check of hunter killed deer and collection of vehicle killed deer in the Oneida-Madison County CWD Containment Area. Despite testing over 7,900 deer, including 1,800 deer from the CWD Containment Area from April 1, 2006 through March 31, 2007, no new cases were detected. CWD surveillance began in New York in 2002, with increased efforts in 2005 after the disease was detected in 5 captive and 2 wild deer in Oneida County. Since 2002, over 18,700 samples have been collected throughout the state, including 3,900 samples from the Oneida-Madison County CWD Containment Area, with no additional positives found. The involved captive facilities were depopulated within weeks of the initial discovery. Regulations prohibiting the feeding of wild deer and restricting the import and movement of live animals and carcasses remain in effect. Surveillance will continue at the same level of effort in the coming year. The NY DEC maintains CWD information at: www.dec.state.ny.us/website/dfwmr/wildlife/deer/cwd.html.
The following press release was issued by the North Dakota Game & Fish Department of April 16, 2007: CWD Test Results All Negative. North Dakota deer and elk populations remain free of chronic wasting disease, according to test results recently received by the state Game and Fish Department. Last fall, North Dakota hunters submitted samples for testing from 2,993 wild deer, 37 elk and four moose collected during the 2006 hunting season. All those samples tested negative, said Erika Butler, Game and Fish Department wildlife veterinarian. Samples for CWD testing were sent to the Wyoming State Veterinary Lab last December. “We are always hopeful that this will be the outcome,” Butler said. “We will continue to be aggressive. In addition to testing any suspect animals throughout the year, we plan to continue our hunter-harvest surveillance in the fall.” Samples in 2006 were collected from hunter-harvested deer taken from all deer hunting units in the state. “Our volunteer cooperation is overwhelming,” Butler said. “We couldn’t achieve our goals without their help. Hunters, meat processors, taxidermists, and the assistance from other agencies are vital in this process.” Since 2002, nearly 8,500 North Dakota deer and 147 elk have tested negative for CWD. To date, CWD has not been diagnosed in wild or farmed deer or elk in North Dakota. Chronic wasting disease affects the nervous system of members of the deer family and is always fatal. Scientists have found no evidence that CWD can be transmitted naturally to humans or livestock. Press release is at: gf.nd.gov/multimedia/news/2007/04/070406.html. North Dakota Game & Fish Department maintains CWD information at: www.gf.nd.gov/hunting/cwd-q-and-a.html.
Leslie McFarlane, Utah Division of Wildlife Resources, provides the following: The Utah Veterinary Diagnostic Laboratory in Logan has completed testing 1,934 mule deer samples collected during the 2006 hunting season by the Utah Division of Wildlife Resources. The positive samples include one deer taken during last fall’s archery season, two harvested during the muzzleloader season, and the remaining four were collected during the rifle hunt. The animals were all harvested in areas where CWD has previously been detected, with 6 from the La Sal Mountains and 1 from Vernal. No positive animals were detected from the central portion of the state. In addition to the deer that were tested, nearly 500 samples from elk were collected and none of these tested positive for the disease. To date, CWD has not been detected in elk from Utah. Since the fall of 2002, nearly 12,000 deer samples have been collected in Utah and tested for CWD. Distribution of CWD in Utah occurs in three distinct geographical areas including central and northeastern Utah, where it is estimated that less than 1 percent of the buck population is affected by CWD. In the LaSal Mountains of southeastern Utah, prevalence rates are estimated to be near 2%. To date, 33 samples collected from mule deer have tested positive for CWD. Twenty-four of the 33 positive samples came from the LaSal Mountains, five from the Vernal area, one near the south end of Flaming Gorge, one near Fountain Green, and two 20 miles north of Fountain Green. The Utah Division of Wildlife Resources maintains CWD information at: wildlife.utah.gov/diseases/cwd.
Levels of Abnormal Prion Protein in Deer and Elk with Chronic Wasting Disease. Brent L. Race, Kimberly D. Meade-White, Anne Ward, Jean Jewell, Michael W. Miller, Elizabeth S. Williams, Bruce Chesebro, and Richard E. Race Emerg Infect Dis. 2007 Jun; [Epub ahead of print].
Abstract: Chronic wasting disease (CWD) of deer and elk is a widespread health concern because its potential for cross-species transmission is undetermined. CWD prevalence in wild elk is much lower than its prevalence in wild deer, and whether CWD-infected deer and elk differ in ability to infect other species is unknown. Because lymphoid tissues are important in the pathogenesis of some transmissible spongiform encephalopathies such as sheep scrapie, we investigated whether CWD-affected elk and deer differ in distribution or quantity of disease-associated prion protein (PrPres) in lymphoid tissues. Immunoblot quantification of PrPres from tonsil and retropharyngeal lymph nodes showed much higher levels of PrPres in deer than in elk. This difference correlated with the natural prevalence of CWD in these species and suggested that CWD-infected deer may be more likely than elk to transmit the disease to other cervids and have a greater potential to transmit CWD to noncervids. www.cdc.gov/eid/content/13/6/pdfs/07-0186.pdf?s_cid=eid07_0186_x.
Abstract: Advances in acquiring and analyzing the spatial attributes of data have greatly enhanced the potential utility of wildlife disease surveillance data for addressing problems of ecological or economic importance. We present an approach for using wildlife disease surveillance data to identify areas for (or of) intervention, to spatially delineate paired treatment and control areas, and then to analyze these nonrandomly selected sites in a meta-analysis framework via before–after–control–impact (BACI) estimates of effect size. We apply these methods to evaluate the effectiveness of attempts to reduce chronic wasting disease (CWD) prevalence through intensive localized culling of mule deer (Odocoileus hemionus) in north-central Colorado, USA. Areas where surveillance data revealed high prevalence or case clusters were targeted by state wildlife management agency personnel for focal scale (on average <17 km2) culling, primarily via agency sharpshooters. Each area of sustained culling that we could also identify as unique by cluster analysis was considered a potential treatment area. Treatment areas, along with spatially paired control areas that we constructed post hoc in a case-control design (collectively called “management evaluation sites”), were then delineated using home range estimators. Using meta-BACI analysis of CWD prevalence data for all management evaluation sites, the mean effect size (change of prevalence on treatment areas minus change in prevalence on their paired control areas) was 0.03 (SE = 0.03); mean effect size on treatment areas was not greater than on paired control areas. Excluding cull samples from prevalence estimates or allowing for an equal or greater two-year lag in system responses to management did not change this outcome. We concluded that management benefits were not evident, although whether this represented true ineffectiveness or was a result of lack of data or insufficient duration of treatment could not be discerned. Based on our observations, we offer recommendations for designing a management experiment with 80% power to detect a 0.10 drop in prevalence over a 6–12-year period. www.esajournals.org/esaonline/?request=get-abstract&issn=1051-0761&volume=017&issue=01&page=0140.
Abstract: Animals that naturally acquire the prion diseases have a well-developed olfactory sense that they utilize for a variety of basic behaviors. To assess the potential for the nasal cavity to serve as a point of entry for prion diseases, a small amount of prion-infected brain homogenate was placed inferior to the nostrils of hamsters, where it was immediately sniffed into the nasal cavity. Hamsters extranasally inoculated with the HY strain of transmissible mink encephalopathy (TME) agent had an incubation period that was not significantly different from per os inoculation of the same dose of the HY TME agent. However, the efficiency of the nasal route of inoculation was determined to be 10 to 100 times greater based on endpoint dilution analysis. Immunohistochemistry on tissues from hamsters killed at 2-week intervals after inoculation was used to identify the disease-associated form of the prion protein (PrPd) to determine the route of prion neuroinvasion. Nasal mucosa-associated lymphoid tissue and submandibular lymph nodes initially accumulated PrPd as early as 4 weeks postinfection. PrPd was first identified in cervical lymph nodes at 8 weeks, in the mesenteric lymph nodes, spleen, and Peyer’s patches at 14 weeks, and in the tongue 20 weeks after inoculation. Surprisingly, there was no evidence of PrPd in olfactory epithelium or olfactory nerve fascicles at any time after inoculation. Therefore, the HY TME agent did not enter the central nervous system via the olfactory nerve; instead, PrPd accumulated in elements of the cranial lymphoreticular system prior to neuroinvasion. jvi.asm.org/cgi/content/abstract/81/9/4482.
Abstract: Transmissible spongiform encephalopathies are fatal neurodegenerative diseases that are caused by unconventional pathogens and affect the central nervous system of animals and humans. Several different forms of these diseases result from natural infection (i.e. exposure to transmissible spongiform encephalopathy agents or prions, present in the natural environment of the respective host). This holds true also for scrapie in sheep, bovine spongiform encephalopathy in cattle, chronic wasting disease in elk and deer, or variant Creutzfeldt–Jakob disease in humans, all of which are assumed to originate predominantly from peroral prion infection. This article intends to provide an overview of the current state of knowledge on the spread of scrapie, chronic wasting disease, bovine spongiform encephalopathy and variant Creutzfeldt–Jakob disease agents through the body in naturally affected hosts, and in model animals experimentally challenged via the alimentary tract. Special attention is given to the tissue components and spreading pathways involved in the key stages of prion routing through the body, such as intestinal uptake, neuroinvasion of nerves and the central nervous system, and centrifugal spread from the brain and spinal cord to peripheral sites (e.g. sensory ganglia or muscles). The elucidation of the pathways and mechanisms by which prions invade a host and spread through the organism can contribute to efficient infection control strategies and the improvement of transmissible spongiform encephalopathy diagnostics. It may also help to identify prophylactic or therapeutic approaches that would impede naturally acquired transmissible spongiform encephalopathy infections. content.febsjournal.org/cgi/content/abstract/274/3/588.
USDA FY08 Budget Request for Chronic Wasting Disease The United States Department of Agriculture’s 2008 budget summary is posted at: www.obpa.usda.gov/budsum/fy08budsum.pdf. Page 76 of this document (Pest and Disease Management Programs) identifies that “Decreased funding is also proposed for brucellosis, chronic wasting disease, pseudorabies, and other efforts.” The line item for CWD in the FY08 President’s Budget Request for USDA is $12.3M, down $6.2M from the FY07 budget estimate of $18.5M. USDA utilizes this funding to provide fiscal support to the states for CWD surveillance activities (both captive and free-ranging). The President’s Budget Request is the initial portion of the federal appropriations process. Congress ultimately determines the level of funding that will be made available to USDA for CWD and other programs.
CWD Update 85 March 24, 2007
State and Provincial Updates
Ontario: John Dungavell, Ontario Ministry of Natural Resources, provides the following: Since 2002, Ontario has conducted CWD surveillance of hunter-harvested deer. The program has tested more than 3500 deer with all negative results to date. Ontario will continue to conduct surveillance activities in the 2007 hunting season. In 2005, the Government of Ontario developed the Ontario CWD Surveillance and Response Plan which outlines the province’s actions with regards to CWD. In November 2005, Ontario passed a regulation restricting the importation of high risk cervid parts (head, spinal column etc.) from other jurisdictions. For more information on the Ontario plan, the regulation, or our surveillance program, please see our CWD website at http://www.mnr.gov.on.ca/MNR/hunting/cwd.
Additionally, if an Ontarian harvests a CWD positive cervid in your jurisdiction, please contact John Dungavell at 705-755-1573.
Pennsylvania: Bob Boyd, Pennsylvania Game Commission, provides the following on their recent CWD exercise: On Nov. 11, 2006, Pennsylvania Game Commission (PGC) Executive Director Carl G. Roe announced that the agency would conduct a CWD response simulation exercise in the first quarter of 2007. To more fully evaluate their preparedness, the Pennsylvania Game Commission developed different scenarios for each of the six region offices and the Harrisburg headquarters. Each scenario had a different set of constructs, variables and challenges that staff had to work through. One week after the exercise commenced, each team reported on their efforts to respond to the simulated discovery of CWD. Details of each response will be incorporated into the agency’s Operational Plan. The decision to hold the drill was a product of two meetings to review and update the state’s CWD response plan, as well as the agency’s internal operational plan. “Currently, there are no confirmed or suspected cases of CWD-infected deer or elk in Pennsylvania, and we are working to ensure that it stays that way,” Roe said. “While there always is room for improvement, I believe that, having gone through this planning exercise, our agency response plan provides a solid foundation should CWD be identified within our borders.
Pennsylvania Game Commission CWD information is at: http://www.pgc.state.pa.us/pgc/cwp/view.asp?a=458&q=163873.
South Dakota: Steve Griffin, South Dakota Game, Fish, and Parks, provides the following: In the South Dakota CWD Surveillance period of July 1, 2006 to February 28, 2007 a total of 2,515 samples were collected for CWD surveillance. Breakdown of the sampling is as follows:
Below is a listing of the positive cervids that have been found in South Dakota during the surveillance period of July 1, 2006 to February, 2007.
In Summary: To date, South Dakota has found 57 cases of CWD (39 deer and 18 elk) in free ranging deer and elk since testing began in 1997. Wind Cave National Park accounts for 16 of these animals (8 elk, 8 deer). Three elk have been found in Custer State Park. A total of 14,817 wild deer and elk have been tested for CWD since 1997.
South Dakota Game, Fish, and Parks CWD information is at: http://www.sdgfp.info/Wildlife/hunting/BigGame/CWD.htm.
Virginia: After extensive testing, the Virginia Department of Game and Inland Fisheries (VDGIF) has not found any evidence of chronic wasting disease (CWD) in Virginia’s white-tailed deer population. In 2006, over 800 samples were collected from white-tailed deer throughout the state. Approximately 500 samples were collected from the active surveillance area, which includes the western and northern parts of Shenandoah, Frederick, Clarke and Loudoun Counties, the area of Virginia closest to where CWD has been detected in West Virginia. All hunters and members of the public are asked to keep a look out for any deer showing symptoms consistent with the disease. These clinical suspects are defined as adult (16 months or older) deer or elk that have poor body condition with neurological signs such as abnormal behavior, tremors, stumbling, incoordination, poor posture including droopy ears and a lowered head, drooling, and excessive thirst, and urination. Anyone who sees a CWD suspect deer should not attempt to contact, disturb or kill the animal. Instead, accurately document the location and immediately contact the Department of Game and Inland Fisheries by calling 1-804-367-1258.
Press Release is at: http://www.dgif.virginia.gov/news/release.asp?id=119.
Virginia Department of Game and Inland Fisheries CWD information is at: http://www.dgif.virginia.gov/cwd.
Wisconsin: Donna Gilson, Wisconsin Department of Agriculture, Trade and Consumer Protection, provides the following:
The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) has confirmed a second CWD-positive white-tailed deer at a Crawford County captive cervid facility. The first positive on this farm was discovered in January 2005, in a 19-month-old buck that died from respiratory causes and was routinely sampled as required for deer that die or are killed at 16 months and older. Subsequent to the initial positive, the State Veterinarian ordered the herd depopulated for testing. However, the owner challenged the USDA’s test results (the USDA’s National Veterinary Services Laboratories in Ames, Iowa, conducts Wisconsin’s captive cervid testing for regulatory purposes). That case is in federal court and therefore the depopulation order is on hold. The second positive was a male born in June 2004. It was found dead Jan. 4, 2007, after an apparent fight with another buck. Again, it was sampled as required under rule. The State Veterinarian was notified by the USDA Area Veterinarian in Charge on Feb. 5 that it was positive for CWD.
Detection of PrPCWD in postmortem rectal lymphoid tissues in Rocky mountain elk (Cervus elaphus nelsoni) infected with chronic wasting disease. Terry R. Spraker, Thomas L. Gidlewski, Aru Balachandran, Kurt C. VerCauteren, Lynn Creekmore and Randy D. Munger Journal of Veterinary Diagnostic Investigation Vol. 18 Issue 6, 553-557.
Abstract: Preclinical diagnostic tests for transmissible spongiform encephalopathies have been described for mule deer (Odocoileus hemionus), using biopsy tissues of palatine tonsil, and for sheep, using lymphoid tissues from palatine tonsil, third eyelid, and rectal mucosa. The utility of examining the rectal mucosal lymphoid tissues to detect chronic wasting disease (CWD) was investigated in Rocky Mountain elk (Cervus elaphus nelsoni), a species for which there is not a live-animal diagnostic test. Postmortem rectal mucosal sections were examined from 308 elk from two privately owned herds that were depopulated. The results of the postmortem rectal mucosal sections were compared to immunohistochemical staining of the brainstem, retropharyngeal lymph nodes, and palatine tonsil. Seven elk were found positive using the brainstem (dorsal motor nucleus of the vagus nerve), retropharyngeal lymph nodes, and palatine tonsil. Six of these elk were also found positive using postmortem rectal mucosal sections. The remaining 301 elk in which CWD-associated abnormal isoform of the prion protein (PrPCWD) was not detected in the brainstem and cranial lymphoid tissues were also found to be free of PrPCWD when postmortem rectal mucosal sections were examined. The use of rectal mucosal lymphoid tissues may be suitable for a live-animal diagnostic test as part of an integrated management strategy to limit CWD in elk. http://jvdi.org/cgi/content/abstract/18/6/553.
UK Red Deer Surveillance for CWD Following agreement between the EU Commission and Member States, a one year Transmissible Spongiform Encephalopathy (TSE) surveillance programme which targets farmed and wild red deer will be undertaken across the Community. The Scottish Executive has announced details of how the surveillance protocols will apply in Scotland. With the assistance of the Deer Commission for Scotland and Forestry Commission Scotland, the sample target of 598 wild red deer animals over 18 months of age will be achieved by taking a percentage of deer culled as part of the normal stock management arrangement, with a further smaller number of animals uplifted following road kills. The sample target is expected to be collected over one hunting season. A further 598 farmed deer are also to be collected under the surveillance target. This part of the sample will be collected through a specialist deer abattoir in England. All animals collected for surveillance purposes will be subject to screening for the presence of TSEs. The sale of venison for public consumption is not under investigation and trade in venison should be unaffected.
Scotland press release at: http://www.scotland.gov.uk/News/Releases/2007/01/23140934.
More information on the UK program: http://www.defra.gov.uk/animalh/bse/pdf/comms_strat.pdf.
CWD Update 84 January 27, 2007
State and Provincial Updates
Alberta: Alberta is continuing testing for the provincial chronic wasting disease (CWD) surveillance program for 2006-07. One additional case of CWD in wild deer was confirmed on January 2. This brings the total to 17 cases in wild deer in Alberta since the first case in September 2005. The most recent case was taken by a hunter near Chauvin, not far from an earlier case reported in late December.
Alberta Sustainable Resource Development’s CWD information is at: www.srd.gov.ab.ca/fw/diseases/CWD. A map showing the locations of Alberta CWD+ animals is at: http://www.srd.gov.ab.ca/fw/diseases/CWD/pdf/CWD_positive_Dec2006.pdf.
West Virginia: On December 22, 2006 the West Virginia DNR announced that a hunter-harvested deer taken during the 2006 hunting season tested positive for CWD. The 2.5 year old buck, one of 1355 deer sampled in Hampshire County during the 2006 hunting season, was taken in close proximity to the previously-established cluster of CWD+ deer in Hampshire County. CWD has now been detected in a total of 10 deer in West Virginia, all in Hampshire County: one road-killed deer, four deer collected by the DNR in 2005, four deer collected by the DNR in 2006 and one hunter-harvested deer during the 2006 deer season.
West Virginia DNR CWD information is at: http://www.wvdnr.gov/hunting/ChronicWaste.shtm. A WVDNR fact sheet is at: http://www.wvdnr.gov/hunting/PDFFiles/CWDfactsheet.pdf.
Wisconsin: The Wisconsin DNR has begun agency sharpshooting at Devil’s Lake State Park and the Southern Unit of Kettle Moraine State Forest. Devil’s Lake S.P. is the furthest north that CWD has been detected in the state; three CWD+ deer have been detected in the 10,200 acre park in Sauk County in the last year. Kettle Moraine State Forest lies just north of the southeastern CWD zone in Wisconsin; five hunter-harvested deer from the 6400 acre Walworth County portion of the forest tested positive this year. In an additional note, the DNR has begun conducting this year’s winter helicopter deer counts in CWD-affected areas. Recent snowfall and cold temperatures are providing good conditions for these efforts to determine deer density within Wisconsin’s CWD zones.
Wisconsin Department of Natural Resources CWD information, including an interactive map showing locations of positives and overall surveillance effort, is at: http://www.dnr.state.wi.us/org/land/wildlife/whealth/issues/CWD/index.htm.
Wyoming: The Wyoming Game and Fish Department has finished its fourth year of comprehensive Chronic Wasting Disease surveillance and added two deer hunt areas and two elk hunt areas to its list of areas where CWD has been detected. Game and Fish personnel collected 4,653 deer, elk and moose samples in 2006. Of those, 116 animals tested positive for CWD – 88 mule deer, 13 white-tailed deer and 15 elk. New cases of CWD were diagnosed in deer hunt area 4 east of Sundance, deer hunt area 11 in Niobrara and Weston counties and elk hunt areas 16 and 22 in northern Carbon County.
The Wyoming Game & Fish Department 2006 surveillance summary press release is at: http://gf.state.wy.us/services/news/pressreleases/06/12/15/061215_2.asp. Wyoming Game & Fish Department CWD Information is at: http://gf.state.wy.us/services/education/cwd/index.asp.
Production of cattle lacking prion protein. Jürgen A Richt, Poothappillai Kasinathan, Amir N Hamir, Joaquin Castilla, Thillai Sathiyaseelan, Francisco Vargas, Janaki Sathiyaseelan, Hua Wu, Hiroaki Matsushita, Julie Koster, Shinichiro Kato, Isao Ishida, Claudio Soto, James M Robl & Yoshimi Kuroiwa Nature Biotechnology 25, 132-138 (2006).
Abstract: Prion diseases are caused by propagation of misfolded forms of the normal cellular prion protein PrPC, such as PrPBSE in bovine spongiform encephalopathy (BSE) in cattle and PrPCJD in Creutzfeldt-Jakob disease (CJD) in humans. Disruption of PrPC expression in mice, a species that does not naturally contract prion diseases, results in no apparent developmental abnormalities. However, the impact of ablating PrPC function in natural host species of prion diseases is unknown. Here we report the generation and characterization of PrPC-deficient cattle produced by a sequential gene-targeting system. At over 20 months of age, the cattle are clinically, physiologically, histopathologically, immunologically and reproductively normal. Brain tissue homogenates are resistant to prion propagation in vitro as assessed by protein misfolding cyclic amplification. PrPC-deficient cattle may be a useful model for prion research and could provide industrial bovine products free of prion proteins. http://www.nature.com/nbt/journal/v25/n1/abs/nbt1271.html
The role of the cellular prion protein in the immune system. J. D. Isaacs, G. S. Jackson, and D. M. Altmann Clinical & Experimental Immunology 146 (1), 1–8 (2006).
Abstract: Prion protein (PrP) plays a key role in the pathogenesis of prion diseases. However, the normal function of the protein remains unclear. The cellular isoform (PrPC) is expressed widely in the immune system, in haematopoietic stem cells and mature lymphoid and myeloid compartments in addition to cells of the central nervous system. It is up-regulated in T cell activation and may be expressed at higher levels by specialized classes of lymphocyte. Furthermore, antibody cross-linking of surface PrP modulates T cell activation and leads to rearrangements of lipid raft constituents and increased phosphorylation of signalling proteins. These findings appear to indicate an important but, as yet, ill-defined role in T cell function. Although PrP-/- mice have been reported to have only minor alterations in immune function, recent work has suggested that PrP is required for self-renewal of haematopoietic stem cells. Here, we consider the evidence for a distinctive role for PrPC in the immune system and what the effects of anti-prion therapeutics may be on immune function. http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2249.2006.03194.x.
Prions and their partners in crime. Byron Caughey and Gerald S. Baron Nature 443, 803-810 (19 October 2006)
Abstract: Prions, the infectious agents of transmissible spongiform encephalopathies (TSEs), have defied full characterization for decades. The dogma has been that prions lack nucleic acids and are composed of a pathological, self-inducing form of the host’s prion protein (PrP). Recent progress in propagating TSE infectivity in cell-free systems has effectively ruled out the involvement of foreign nucleic acids. However, host-derived nucleic acids or other non-PrP molecules seem to be crucial. Interactions between TSE-associated PrP and its normal counterpart are also pathalogically important, so the physiological functions of normal PrP and how they might be corrupted by TSE infections have been the subject of recent research. http://www.nature.com/nature/journal/v443/n7113/abs/nature05294.html.
The following review article, authored by Beth Williams, was published in 2005, following her unfortunate and untimely death. While aspects of our knowledge regarding CWD have been updated by more recent science, this review article is probably the most thorough ever written and is highly recommended to bolster the reader’s overall understanding of CWD.
Chronic Wasting Disease. E. S. Williams Veterinary Pathology 42:530–549 (2005)
Abstract: Chronic wasting disease (CWD) is a unique transmissible spongiform encephalopathy (TSE) of mule deer (Odocoileus hemionus), white-tailed deer (O. virginianus), and Rocky Mountain elk (Cervus elaphus nelsoni). The natural history of CWD is incompletely understood, but it differs from scrapie and bovine spongiform encephalopathy (BSE) by virtue of its occurrence in nondomestic and free-ranging species. CWD has many features in common with scrapie, including early widespread distribution of disease-associated prion protein (PrPd) in lymphoid tissues, with later involvement of central nervous system (CNS) and peripheral tissues. This distribution likely contributes to apparent efficiency of horizontal transmission and, in this, is similar to scrapie and differs from BSE. Clinical features and lesions of CWD are qualitatively similar to the other animal TSEs. Microscopically, marked spongiform lesions occur in the central nervous system (CNS) after a prolonged incubation period and variable course of clinical disease. During incubation, PrPd can be identified in tissues by antibody-based detection systems. Although CWD can be transmitted by intracerebral inoculation to cattle, sheep, and goats, ongoing studies have not demonstrated that domestic livestock are susceptible via oral exposure, the presumed natural route of exposure to TSEs. Surveillance efforts for CWD in captive and free-ranging cervids will continue in concert with similar activities for scrapie and BSE. Eradication of CWD in farmed cervids is the goal of state, federal, and industry programs, but eradication of CWD from free-ranging populations of cervids is unlikely with currently available management techniques. http://www.vetpathology.org/cgi/content/abstract/42/5/530.
Transmissible Spongiform Encephalopathies: The Definitive American TSE Meeting February 12-13, 2007, Baltimore, Maryland http://www.healthtech.com/2007/tse/index.asp
CWD Update 82 November 20, 2006
New York: John Major, New York Department of Environmental Conservation (DEC), provides the following: For 2006, Chronic Wasting Disease regulations in New York have been updated in response to the finding of the disease in a moose in Colorado and deer in West Virginia. Hunters bringing carcasses into New York from West Virginia must now process them to remove tissues of concern prior to import, and moose have been added to the list of susceptible species that previously included deer and elk. Last year, more than 8,000 wild deer were tested for CWD in New York following the discovery of CWD in 2 wild and 5 captive deer in April 2005, and no additional animals have tested positive for the disease. Special restrictions are in place within the CWD Containment Area of Oneida and Madison counties governing how harvested deer and specific deer parts may be possessed, transported, and disposed. Mandatory testing of all deer taken in the Containment Area will be occurring again this fall, as well as random testing in other counties throughout New York State. Surveillance will continue at the same level this year. As of November 17, more than 3,200 samples (including more than 800 from the Containment Area) have been tested this year, none have detected CWD. The NY DEC maintains CWD information at: http://www.dec.state.ny.us/website/dfwmr/wildlife/deer/cwd.html.
Wisconsin: The Wisconsin DNR has been diligently working to manage CWD since it was detected in free-ranging deer in 2002. In September, DNR staff held a retreat to discuss their progress, relevant science, and future management options. On October 25, WDNR Secretary Scott Hassett presented a memo to the WI DNR Board, outlining the CWD situation in Wisconsin. Secretary Hassett’s memo can be viewed at: http://www.dnr.state.wi.us/org/land/wildlife/whealth/issues/cwd/doc/Hasset_CWDMgmt.pdf.
Also in Wisconsin, the Legislative Audit Bureau recently completed an audit of Wisconsin’s CWD program. The results of the audit (98 page report) can be obtained at: http://www.legis.state.wi.us/lab/reports/06-13Full.pdf. The four page summary report is at: http://www.legis.state.wi.us/lab/reports/06-13Full.pdf. Response from the Wisconsin DNR, including their formal response and press release are at: http://www.dnr.state.wi.us/org/land/wildlife/whealth/issues/CWD/index.htm.
Wyoming: A male white-tailed deer killed in Hunt Area 4, east of Sundance in the Moskee area on November 4, 2006 has tested positive for CWD. Hunt Area 4 borders the Wyoming/South Dakota state line. This is the first CWD-positive animal reported in this hunt area. Press Release available at: http://gf.state.wy.us/services/news/pressreleases/06/11/17/061117_3.asp Wyoming G&F CWD information is at: http://gf.state.wy.us/services/education/cwd/index.asp.
Northeast Association of Fish and Wildlife Agencies: On November 2, 2006, the Northeast Association adopted a regional CWD Plan. Here (PDF) is a link to the document.
Infectious agent of sheep scrapie may persist in the environment for at least 16 years. Gudmundur Georgsson, Sigurdur Sigurdarson and Paul Brown J Gen Virol 87 (2006), 3737-3740; DOI 10.1099/vir.0.82011-0
Abstract: In 1978, a rigorous programme was implemented to stop the spread of, and subsequently eradicate, sheep scrapie in Iceland. Affected flocks were culled, premises were disinfected and, after 2–3 years, restocked with lambs from scrapie-free areas. Between 1978 and 2004, scrapie recurred on 33 farms. Nine of these recurrences occurred 14–21 years after culling, apparently as the result of environmental contamination, but outside entry could not always be absolutely excluded. Of special interest was one farm with a small, completely self-contained flock where scrapie recurred 18 years after culling, 2 years after some lambs had been housed in an old sheep-house that had never been disinfected. Epidemiological investigation established with near certitude that the disease had not been introduced from the outside and it is concluded that the agent may have persisted in the old sheep-house for at least 16 years. http://vir.sgmjournals.org/cgi/content/abstract/87/12/3737
A blood test for prion: disease associated prion aggregate is detected in the blood of infected but asymptomatic animals. Binggong Chang, Xin Cheng, Shaoman Yin, Tao Pan, Hongtao Zhang, Poki Wong, Shin-Chung Kang, Fan Xiao, Huimin Yan, Chaoyang Li, Lisa L. Wolfe, Michael W. Miller, Thomas Wisniewski, Mark I. Greene, and Man-Sun Sy Clin. Vaccine Immunol. doi:10.1128/CVI.00341-06
Abstract: We have developed a sensitive in vitro assay for detecting disease associated prion aggregates by combining an aggregation specific enzyme-linked immunosorbent assay (AS-ELISA) with a Fluorescent Amplification Catalyzed by T7 RNA polymerase Technique (FACTT). The new assay, named AS-FACTT, is much more sensitive than AS-ELISA and could detect prion aggregates in the brain of mice as early as 7 days after an intra-peritoneal inoculation of PrPSc. However, AS-FACTT was still unable to detect prion aggregates in blood of infected mice. To further improve the detection limit of AS-FACTT, we added an additional prion amplification step (Am) and developed a third generation assay, termed Am-A-FACTT. Am-A-FACTT has 100% sensitivity and specificity in detecting disease-associated prion aggregates in blood of infected mice at late but still asymptomatic stages of disease. At a very early stage, Am-A-FACTT had a sensitivity of 50% and specificity of 100%. Most importantly, Am-A-FACTT also detects prion aggregates in blood of mule deer infected with a naturally occurring prion disease, chronic wasting disease. Application of this assay to cattle, sheep, and humans could safeguard food supplies and prevent human contagion. http://cvi.asm.org/cgi/content/abstract/CVI.00341-06v1
Spatial Epidemiology of Chronic Wasting Disease in Wisconsin White-Tailed Deer. Damien O. Joly, Michael D. Samuel, Julia A. Langenberg, Julie A. Blanchong, Carl A. Batha, Robert E. Rolley, Delwyn P. Keane and Christine A. Ribic Journal of Wildlife Diseases, 42(3), 2006, pp. 578-588
Abstract: Chronic wasting disease (CWD) is a fatal, emerging disease of cervids associated with transmissible protease-resistant prion proteins. The potential for CWD to cause dramatic declines in deer and elk populations and perceived human health risks associated with consuming CWD-contaminated venison have led wildlife agencies to embark on extensive CWD control programs, typically involving culling to reduce deer populations. We characterized the spatial distribution of CWD in white-tailed deer (Odocoileus virginianus) in Wisconsin to facilitate CWD management. We found that CWD prevalence declined with distance from a central location, was locally correlated at a scale of 3.6 km, and was correlated with deer habitat abundance. The latter result is consistent with patterns expected for a positive relationship between density and prevalence of CWD. We recommend management activities focused on culling in geographic areas with high prevalence to have the greatest probability of removing infected individuals. Further research is needed to elucidate the factors involved in CWD spread and infection rates, especially the role of density-dependent transmission. http://www.jwildlifedis.org/cgi/content/abstract/42/3/578
White-Tailed Deer Harvest from the Chronic Wasting Disease Eradication Zone in South-Central Wisconsin. Julie A. Blanchong, Damien O. Joly, Michael D. Samuel, Julia A. Langenberg, Robert E. Rolley and Janet F. Sausen Wildlife Society Bulletin 34(3):725-731
Abstract: Chronic wasting disease (CWD) was discovered in free-ranging white-tailed deer (Odocoileus virginianus) in south-central Wisconsin in 2002. The current control method for CWD in the state is the harvest of deer from affected areas to reduce population density and lower CWD transmission. We used spatial regression methods to identify factors associated with deer harvest across south-central Wisconsin. Harvest of deer by hunters was positively related to deer density (slope¼0.003, 95%CI¼0.0001–0.006), the number of landowners that requested harvest permits (slope¼0.071, 95% CI¼0.037–0.105), and proximity to the area of highest CWD infection (slope¼_0.041, 95% CI¼_0.056–_0.027). Concomitantly, harvest was not impacted in areas where landowners signed a petition protesting intensive deer reduction (slope ¼_0.00006, 95% CI ¼_0.0005–0.0003). Our results suggest that the success of programs designed to reduce deer populations for disease control or to reduce overabundance in Wisconsin are dependent on landowner and hunter participation. We recommend that programs or actions implemented to eradicate or mitigate the spread of CWD should monitor and assess deer population reduction and evaluate factors affecting program success to improve methods to meet management goals.
Passage of chronic wasting disease prion into transgenic mice expressing Rocky Mountain elk (Cervus elaphus nelsoni) PrPC. Giuseppe LaFauci, Richard I. Carp, Harry C. Meeker, Xuemin Ye, Jae I. Kim, Michael Natelli, Marisol Cedeno, Robert B. Petersen, Richard Kascsak and Richard Rubenstein J Gen Virol 87 (2006), 3773-3780; DOI 10.1099/vir.0.82137-0
Abstract: Chronic wasting disease (CWD) of elk (Cervus elaphus nelsoni) and mule deer (Odocoileus hemionus) is one of three naturally occurring forms of prion disease, the others being Creutzfeldt–Jakob disease in humans and scrapie in sheep. In the last few decades, CWD has spread among captive and free-ranging cervids in 13 US states, two Canadian provinces and recently in Korea. The origin of the CWD agent(s) in cervids is not known. This study describes the development of a transgenic mouse line (TgElk) homozygous for a transgene array encoding the elk prion protein (PrPC) and its use in propagating and simulating CWD in mice. Intracerebral injection of one mule deer and three elk CWD isolates into TgElk mice led to disease with incubation periods of 127 and 95 days, respectively. Upon secondary passage, the incubation time was reduced to 108 and 90 days, respectively. Upon passage into TgElk mice, CWD prions (PrPSc) maintained the characteristic Western blot profiles seen in CWD-affected mule deer and elk and produced histopathological modifications consistent with those observed in the natural disease. The short incubation time observed on passage from cervid to mouse with both mule deer and elk CWD brain homogenates and the demonstrated capacity of the animals to propagate (mouse to mouse) CWD agents make the TgElk line a valuable model to study CWD agents in cervid populations. In addition, these results with this new transgenic line suggest the intriguing hypothesis that there could be more than one strain of CWD agent in cervids. http://vir.sgmjournals.org/cgi/content/abstract/87/12/3773
The 67th Midwest Fish and Wildlife Conference December 3-6, 2006 Omaha, Nebraska http://www.ngpc.state.ne.us/midwest2006 A special CWD session will be held on Tuesday, December 5. Eleven papers on CWD will be presented. Titles and abstracts are available on the conference web site. Click on “Program @ Glance” then “CWD Symposium.”
Transmissible Spongiform Encephalopathies: The Definitive American TSE Meeting February 12-13, 2007 Baltimore, Maryland http://www.healthtech.com/2007/tse/index.asp The conference agenda can be downloaded from the conference web site. Early registration closes December 1.