State and Provincial Updates
Michigan The following press release was issued on May 26, 2015 by the Michigan Department of Natural Resources
Michigan confirms first case of CWD in free-ranging white-tailed deer
The Michigan departments of Natural Resources (DNR) and Agriculture and Rural Development (MDARD) today confirmed that a free-ranging deer in Meridian Township (Ingham County) has tested positive for chronic wasting disease (CWD), a fatal neurological disease that affects white-tailed deer, mule deer, elk and moose. This is the first time the disease has been found in Michigan’s free-ranging deer population. In 2008 a white-tailed deer from a privately owned cervid (POC) facility in Kent County tested positive for CWD. The animal was observed last month wandering around a Meridian Township residence and showing signs of illness. The homeowner contacted the Meridian Township Police Department, who then sent an officer to euthanize the animal. The deer was collected by a DNR wildlife biologist and delivered for initial testing to the DNR Wildlife Disease Laboratory at the Michigan State University Diagnostic Center for Population and Animal Health in Lansing, Michigan.
After initial tests were positive, samples were forwarded to the U.S. Department of Agriculture’s National Veterinary Services Laboratory in Ames, Iowa, for final confirmation. The Michigan DNR received that positive confirmation last week. To date, there is no evidence that chronic wasting disease presents any risk to non-cervids, including humans, either through contact with an infected animal or from handling contaminated venison. However, as a precaution, the U.S. Centers for Disease Control and the World Health Organization recommend that infected animals not be consumed as food by either humans or domestic animals. “This is the first case of chronic wasting disease to be confirmed in a free-ranging Michigan white-tailed deer,” said DNR Director Keith Creagh. “While it is a disappointing day for Michigan, the good news is that we are armed with a thoughtfully crafted response plan,” Creagh said. “We are working with other wildlife experts at the local, regional, state and federal level, using every available resource, to determine the extent of this disease, respond appropriately to limit further transmission, and ultimately eradicate the disease in Michigan if possible.” The confirmed positive finding triggers several actions in the state’s surveillance and response plan for chronic wasting disease. The plan was developed in 2002 through cooperation between the DNR and MDARD, and was updated in 2012.
Actions the DNR will take include: 1. Completing a population survey in the area where the CWD-positive deer was found. 2. Establishing a Core CWD Area consisting of Alaiedon, Delhi, Lansing, Meridian, Wheatfield and Williamstown townships in Ingham County; Bath and DeWitt townships in Clinton County; and Woodhull Township in Shiawassee County. Unlimited antlerless deer hunting licenses will be available. Mandatory checking of deer will be required in this area during hunting seasons and restrictions will apply to the movement of carcasses and parts of deer taken in this area. 3. Creating a CWD Management Zone, which will include Clinton, Ingham and Shiawassee counties. 4. Implementing a deer and elk feeding and baiting ban, which will include the Core CWD Area and the larger three-county CWD Management Zone. 5. Prohibiting the possession or salvage of deer killed by collision with a motor vehicle within the Core CWD Area. Also, residents are asked to call in the locations of road-killed deer within this area so DNR staff can pick up for testing. Research shows CWD-infected deer are more likely to be hit by vehicles because of their illness.
DNR Director Creagh will issue an interim order approving immediate implementation of these actions. “MDARD is working with the state’s privately owned cervid facilities within a 15-mile surveillance zone to ensure compliance with CWD testing requirements,” said MDARD State Veterinarian James Averill. “For POC facilities located outside of the surveillance zone, there will be no impact. We are, however, encouraging all POCs to continue to be our partners in the state’s CWD testing program.” Chronic wasting disease first was identified in 1967 as a clinical disease in captive mule deer at the Colorado Division of Wildlife Foothills Wildlife Research Facility in Fort Collins, Colorado. Since then, most CWD cases have occurred in western states, but in the past 15 years it has spread to some midwestern and eastern states. The disease is caused by the transmission of infectious, self-multiplying proteins (prions) contained in saliva and other body fluids of infected animals.
Susceptible animals can acquire CWD by direct exposure to these fluids or from environments contaminated with these fluids or the carcass of a diseased animal. Once contaminated, research shows that soil can remain a source of infection for long periods of time, making CWD a particularly difficult disease to eradicate. Some chronically CWD-infected animals will display abnormal behaviors, progressive weight loss and physical debilitation. There is no cure; once a deer is infected with CWD, it will die. Although this is the first positive CWD finding in the state’s free-ranging deer population, it is important to note that from Jan. 1, 1998, through Dec. 31, 2014, tens of thousands of free-ranging Michigan deer were tested and no evidence was found of chronic wasting disease in this population. In fact, that testing included 34,207 deer, 1,607 elk and 70 moose – a large sample of animals with no positive finding. In privately owned deer populations, approximately 21,000 samples have to date been tested for CWD. All of those have been negative as well, with the exception of the 2008 Kent County case. MDARD conducts ongoing surveillance of Michigan’s 365 registered, privately owned cervid facilities.
Public awareness, support “Strong public awareness and cooperation from residents and hunters are critical for a rapid response to evaluate any deer suspected of having chronic wasting disease,” said Steve Schmitt, veterinarian-in-charge at the DNR Wildlife Disease Lab. “We’d like to thank the resident who called local authorities, as well as the Meridian Township Police Department for its swift response.” The DNR asks help from the public and hunters in reporting deer that are: ?
- Unusually thin.
- Exhibiting unusual behavior (for example, acting tame around humans and allowing someone to approach).
To report a suspicious-looking deer, call the DNR Wildlife Disease Lab at 517-336-5030 or fill out and submit the online observation report found on the DNR website. To report road-kills found in the Core CWD Area call the Wildlife Disease Hotline at 517-614-9602 during office hours. Leave a voicemail with location information and staff will attempt to pick up carcasses on the next open business day. Additionally, Schmitt said hunters will play a key role in helping the state manage this new wildlife challenge. “Michigan has a long tradition of hunter support and conservation ethics. Now, with the CWD finding, that support is needed more than ever,” Schmitt said. “Historically, areas where chronic wasting disease has been found have experienced a decline in hunter numbers. Because hunters are often familiar with the deer herd locally, one of the best things they can do to help manage this disease is to continue hunting and bring their deer to check stations this season.” Once the DNR has conducted targeted surveillance in the CWD Management Zone, staff will have a better understanding of needed changes in hunting regulations for upcoming deer hunting seasons. Despite the CWD finding, Schmitt said there is reason for optimism. “When it comes to chronic wasting disease, Michigan isn’t alone. A total of 23 states and two Canadian provinces have found CWD in either free-ranging or privately owned cervids, or both,” he said. “Michigan will take full advantage of the collective expertise and experience of those who have for years now dealt with chronic wasting disease on a daily basis.” Get more information on CWD – including Michigan’s CWD surveillance and response plan, FAQs and a link to the CWD Alliance website where more photos and video are available – at www.michigan.gov/cwd.
Chronic Wasting Disease (CWD) Surveillance Update: April 10, 2015 We have completed all of the 2014 fall CWD surveillance samples received to date. In 2014 we tested 4,163 heads and detected 86 cases of CWD (2.1%). CWD was confirmed in 74 mule deer (59 males, 15 females; 72 adults, 2 yearlings) and 12 white-tails (all males; 10 adults, 2 yearlings). However in the 2014 data the extraordinarily large number of elk heads tested (n= 909, all negative) many of which were harvested in conjunction with hunting opportunities at Canadian Forces Base Suffield in January and February 2015, provides a confounding factor in comparison to previous years. Thus, to allow valid comparisons among years, the proportion of infected animals is presented in the context of the number of heads tested for each species.
In breaking down the identified 2014 sample, CWD was detected in: ? 3.61% of 2048 mule deer
? 1.13% of 1062 white-tailed deer
? 0 of 131 moose
? 0 of 909 elk
An overview of the 2014 results reveals both expected and unexpected patterns in the data. As in previous years, mule deer remain the species at greatest risk of CWD (74 of 86 (86.0%) cases detected in 2014). However the ratio of infected males to females wherever CWD occurs generally is ~2:1; but in 2014 the ratio in the Alberta sample was ~5:1 (71 males, 15 females). The reason for the unexpected increase in the proportion of infected males is unknown, particularly since almost equal numbers of male and female mule deer, the species at greatest risk, were tested in 2014 (n = 1040 and 1065, respectively).
Overall number (86 cases) and rate (2.1%) of CWD positive deer in 2014 are significantly higher than in previous years. Similarly the geographic distribution of CWD in eastern Alberta continues to expand. The disease now occurs in local areas from the Battle River watershed in the north to the Milk River in the south. We detected the first evidence of CWD in the Hand Hills area northeast of Drumheller in WMU 160, first evidence of the disease in the Bow River watershed (east of Lake Newell), and further evidence of the disease in the vicinity of Canadian Forces Base (CFB) Suffield and the Cypress Hills. However no CWD was found in elk harvested from CFB Suffield, despite testing over 870 elk heads from WMU 732.
The disease remains well established in areas directly adjacent to the Saskatchewan border and continues to expand into WMUs further up the affected watersheds, primarily the Battle, Red Deer, and South Saskatchewan rivers.
The following press release was issued by the Missouri Department of Conservation on March 10, 2015
MDC reports 11 new cases of CWD in Missouri deer JEFFERSON CITY, Mo. — The Missouri Department of Conservation (MDC) reports that 11 new cases of Chronic Wasting Disease (CWD) have recently been found in deer harvested in Macon, Adair, and now Cole counties. A buck harvested near the village of Centertown in Cole County is the first case of the disease to be found outside of the Department’s six-county CWD Containment Zone of Adair, Chariton, Linn, Macon, Randolph, and Sullivan counties. All previous cases have been limited to Macon, Linn, and Adair counties.
These 11 new cases bring the total number of Missouri free-ranging deer that have tested positive for CWD to 14 for this past season and 24 overall since the disease was first discovered in the state in 2010 at a private hunting preserve in Linn County. CWD has also been found in 11 captive deer in Macon and Linn counties.
The Department has collected more than 43,000 tissue samples since it began testing for the emerging disease in 2001. MDC has collected more than 3,400 tissue samples for CWD testing from harvested and other free-ranging deer this season. Results for about 330 tissue samples are still in the process of being tested by an independent, outside laboratory.
“We will provide an update of final results once all testing has been completed for the season,” said MDC Deer Biologist Jason Sumners. “We will continue to monitor the spread of the disease through more CWD testing this coming fall and winter. We are also updating our efforts to help contain the spread of the disease and will be working out the details over this spring and summer.”
Chronic Wasting Disease infects only deer and other members of the deer family by causing degeneration of the brain. The disease has no vaccine or cure and is 100-percent fatal. Missouri offers some of the best deer hunting in the country, and deer hunting is an important part of many Missourians’ lives and family traditions. Infectious diseases such as CWD could reduce hunting and wildlife-watching opportunities for Missouri’s nearly 520,000 deer hunters and almost two million wildlife watchers. Deer hunting is also an important economic driver in Missouri and gives a $1 billion annual boost to state and local economies.
Lower deer numbers from infectious diseases such as CWD could hurt 12,000 Missouri jobs and many businesses that rely on deer hunting as a significant source of revenue, such as meat processors, taxidermists, hotels, restaurants, sporting goods stores, and others. CWD also threatens the investments of thousands of private landowners who manage their land for deer and deer hunting, and who rely on deer and deer hunting to maintain property values.
For more information on CWD in Missouri, visit the MDC website at http://mdc.mo.gov/hunting-trapping/deer-hunting/deer-diseases/chronic-wasting-disease.
Survival and Population Growth of a Free-Ranging Elk Population with a Long History of Exposure to Chronic Wasting Disease Ryan J. Monello, Jenny G. Powers, N. Thompson Hobbs, Terry R. Spraker, Mary Kay Watry and Margaret A. Wild The Journal of Wildlife Management 78(2):214–223; 2014; DOI: 10.1002/jwmg.665
Abstract: Investigations of chronic wasting disease (CWD), a fatal, contagious prion disease of free ranging cervids, suggest the disease can cause long-term population declines in deer (Odocoileus spp.). However, the implications of CWD for elk (Cervus elaphus nelsoni) populations are less certain. During 2008–2010, we used rectal biopsies and telemetry to observe disease transmission and survival in adult female elk from a high-density herd in Rocky Mountain National Park (RMNP) that had been infected by CWD for over 25 years. We studied a cohort of 123 adult female elk that were determined to be free of CWD by rectal biopsy in 2008. Annual incidence of CWD was 0.08 [95% Bayesian credible interval (BCI)?0.05, 0.12]. Annual survival probabilities of the cohort excluding harvest declined from 0.97 in 2008 (BCI?0.93, 0.99) to 0.85 in 2010 (BCI?0.75, 0.93). Declines in survival were attributed almost entirely to CWD; the proportion of radiocollared elk that died of CWD increased from 0.02 in 2008 (BCI?0.00, 0.05) to 0.11 in 2010 (BCI?0.04, 0.21). We attributed the increase to the time lag required for development of new CWD cases. We used survival rates of susceptible and infected elk to develop a projection matrix for a discrete time, female only model that estimated the intrinsic population growth rate (l) of this elk herd to be 1.00 (BCI?0.93, 1.05) using the prevalence of CWD (12.9%) and calf:cow ratios (24:100) observed during this study. Population declines were predicted to occur when prevalence of CWD exceeded 13% (BCI?0, 35). However, this estimate was contingent on calf:cow ratios and harvest. Greater recruitment will offset some of the effects of CWD, whereas the inclusion of female harvest, which was excluded from this study, would likely result in lower l values than those observed in this study. We conclude that CWD can exceed natural rates of mortality, reduce survival of adult females, and decrease population growth of elk herds. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. http://onlinelibrary.wiley.com/doi/10.1002/jwmg.665/abstract Human prion protein sequence elements impede cross-species chronic wasting disease transmission
Timothy D. Kurt, Lin Jiang, Natalia Fernández-Borges, Cyrus Bett, Jun Liu, Tom Yang, Terry R. Spraker, Joaquín Castilla, David Eisenberg, Qingzhong Kong, and Christina J. Sigurdson The Journal of Clinical Investigation. 2015. doi:10.1172/JCI79408
Chronic wasting disease (CWD) is a fatal prion disease of North American deer and elk and poses an unclear risk for transmission to humans. Human exposure to CWD occurs through hunting activities and consumption of venison from prion infected animals. Although the amino acid residues of the prion protein (PrP) that prevent or permit human CWD infection are unknown, NMR-based structural studies suggest that the ?2-?2 loop (residues 165–175) may impact species barriers. Here we sought to define PrP sequence determinants that affect CWD transmission to humans. We engineered transgenic mice that express human PrP with four amino acid substitutions that result in expression of PrP with a ?2-?2 loop (residues 165–175) that exactly matches that of elk PrP. Compared with transgenic mice expressing unaltered human PrP, mice expressing the human-elk chimeric PrP were highly susceptible to elk and deer CWD prions but were concurrently less susceptible to human Creutzfeldt-Jakob disease prions. A systematic in vitro survey of amino acid differences between humans and cervids identified two additional residues that impacted CWD conversion of human PrP. This work identifies amino acids that constitute a substantial structural barrier for CWD transmission to humans and helps illuminate the molecular requirements for cross-species prion transmission.
http://www.jci.org/articles/view/79408 Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions
Sandra Pritzkow, Rodrigo Morales, Fabio Moda, Uffaf Khan, Glenn C. Telling, Edward Hoover, and Claudio Soto Cell Reports 11, 1–8, May 26, 2015. doi:10.1016/j.celrep.2015.04.036
Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here, we analyzed the binding and retention of infectious prion protein (PrPSc) to plants. Small quantities of PrPSc contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild-type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrPSc for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease.
Circulation of prions within dust on a scrapie affected farm Kevin C Gough, Claire A Baker, Hugh A Simmons, Steve A Hawkins and Ben C Maddison
Veterinary Research (2015) 46:40 DOI 10.1186/s13567-015-0176-1
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. http://www.biomedcentral.com/content/pdf/s13567-015-0176-1.pdf