Chronic Wasting Disease Active
Chronic wasting disease (CWD) is an emerging infectious disease that is fatal to free-ranging and captive animals in Cervidae, the deer family. CWD is one member of a family of diseases called transmissible spongiform encephalopathies (TSEs), and is thought to be caused by prions. CWD is the only TSE known to affect free-ranging wildlife.
Since its initial identification in Colorado in captive mule deer in the late 1960s and free-ranging elk in the 1980s, chronic wasting disease (CWD) has affected captive and free-ranging cervids (members of the deer family) in about half the States in the United States, as well as Canada, South Korea, Norway, Finland, and Sweden, and continues to spread across North America through new and recurring outbreaks. The only prion disease known to affect free-ranging wildlife, CWD is increasing in prevalence in areas where the disease is already established. In heavily affected areas of Wyoming, Colorado, and Wisconsin, more than 40% of free-ranging cervids are infected; wildlife managers and researchers have documented CWD-associated population declines in white-tailed deer, mule deer, and elk.
CWD is one member of a family of diseases called transmissible spongiform encephalopathies (TSEs), which includes scrapie in sheep and goats, bovine spongiform encephalopathy (commonly called “mad cow disease”) in cattle, and Creutzfeldt Jakob disease in humans. The causative agents of TSEs are thought to be prions. Prions are unconventional pathogenic agents that are comprised mostly, if not entirely, of an abnormal, infectious form of a normally occurring host protein called a prion protein. Prion proteins are found most abundantly in mammalian brain and central nervous system tissues. Currently, effective treatment for CWD does not exist, and management practices to prevent disease transmission in cervids are limited.
Scientists at the USGS National Wildlife Health Center (NWHC) work collaboratively with and provide technical assistance to various federal, state, and tribal natural resources agencies, academic institutions, nongovernmental organizations and industry partners. Some of these collaborative efforts include, but are not limited to:
- Understanding the biology, ecology, and epidemiology of CWD
- Assessing and predicting the spread and persistence of CWD in wildlife and the environment; and
- Developing tools for early detection, diagnosis, surveillance, and control of CWD.
Research performed at the NWHC has been instrumental in developing surveillance strategies for early detection of CWD in Montana (Montana Fish, Wildlife and Parks Department) and Shenandoah National Park (National Park Service), identifying potential disease risks posed by CWD to noncervid species such as bighorn sheep, and identifying environmental factors, like soil and plants, that may facilitate CWD transmission on the landscape.
The benefits of USGS research on CWD extend beyond wildlife management. For example, USGS scientists identified a novel enzyme from lichens with the ability to break down infectious prion protein that is being studied for its use in decontaminating human hospital environments in collaboration with an industry partner. Efforts will continue to focus on improving diagnostic testing platforms in collaboration with the U.S. Food and Drug Administration, providing surveillance and modeling technical assistance to a long-term CWD study carried out by the Wisconsin Department of Natural Resources, developing modeling techniques for predicting CWD growth within free-ranging cervid populations and forecasting disease spread in regions of interest, and continued identification and development of novel anti-prion compounds and processes to disrupt disease transmission cycles.
In addition to research, the NWHC also conducts numerous communications and outreach activities and products, such as fact sheets, briefings, media interviews, and presentations, on both a national and international scale.
To learn more about Chronic Wasting Disease, see our fact sheet - Chronic Wasting Disease: Status, Science, and Management Support by the U.S. Geological Survey.
To learn more about the plan for assisting states, federal agencies, and tribes in managing chronic wasting disease in wild and captive cervids, see - Federal Plan for Assisting States, Federal Agencies, and Tribes 2002.
Access up-to-date maps of the expanding distribution of chronic wasting disease.
Below are other science projects associated with this project.
Below are multimedia items associated with chronic wasting disease.
Below are publications about chronic wasting disease.
Chronic wasting disease—Status, science, and management support by the U.S. Geological Survey
Using auxiliary information to improve wildlife disease surveillance when infected animals are not detected: A Bayesian approach
Using landscape epidemiological models to understand the distribution of chronic wasting disease in the Midwestern USA
In vitro prion protein conversion suggests risk of bighorn sheep (Ovis canadensis) to transmissible spongiform encephalopathies
Association mapping of genetic risk factors for chronic wasting disease in wild deer
Evaluating spatial overlap and relatedness of white-tailed deer in a chronic wasting disease management zone
Deer density and disease prevalence influence transmission of Chronic Wasting Disease in White-tailed Deer
Effects of chronic wasting disease on reproduction and fawn harvest vulnerability in Wisconsin white-tailed deer
Prion protein degradation by lichens of the genus Cladonia
The role of genetics in chronic wasting disease of North American cervids
Emerging prion disease drives host selection in a wildlife population
Enhanced surveillance strategies for detecting and monitoring chronic wasting disease in free-ranging cervids
Highly efficient amplification of chronic wasting disease agent by protein misfolding cyclical amplification with beads (PMCAb)
Below are news stories about chronic wasting disease.
Below are FAQs about chronic wasting disease.
- Overview
Chronic wasting disease (CWD) is an emerging infectious disease that is fatal to free-ranging and captive animals in Cervidae, the deer family. CWD is one member of a family of diseases called transmissible spongiform encephalopathies (TSEs), and is thought to be caused by prions. CWD is the only TSE known to affect free-ranging wildlife.
Since its initial identification in Colorado in captive mule deer in the late 1960s and free-ranging elk in the 1980s, chronic wasting disease (CWD) has affected captive and free-ranging cervids (members of the deer family) in about half the States in the United States, as well as Canada, South Korea, Norway, Finland, and Sweden, and continues to spread across North America through new and recurring outbreaks. The only prion disease known to affect free-ranging wildlife, CWD is increasing in prevalence in areas where the disease is already established. In heavily affected areas of Wyoming, Colorado, and Wisconsin, more than 40% of free-ranging cervids are infected; wildlife managers and researchers have documented CWD-associated population declines in white-tailed deer, mule deer, and elk.
CWD is one member of a family of diseases called transmissible spongiform encephalopathies (TSEs), which includes scrapie in sheep and goats, bovine spongiform encephalopathy (commonly called “mad cow disease”) in cattle, and Creutzfeldt Jakob disease in humans. The causative agents of TSEs are thought to be prions. Prions are unconventional pathogenic agents that are comprised mostly, if not entirely, of an abnormal, infectious form of a normally occurring host protein called a prion protein. Prion proteins are found most abundantly in mammalian brain and central nervous system tissues. Currently, effective treatment for CWD does not exist, and management practices to prevent disease transmission in cervids are limited.
Scientists at the USGS National Wildlife Health Center (NWHC) work collaboratively with and provide technical assistance to various federal, state, and tribal natural resources agencies, academic institutions, nongovernmental organizations and industry partners. Some of these collaborative efforts include, but are not limited to:
- Understanding the biology, ecology, and epidemiology of CWD
- Assessing and predicting the spread and persistence of CWD in wildlife and the environment; and
- Developing tools for early detection, diagnosis, surveillance, and control of CWD.
Research performed at the NWHC has been instrumental in developing surveillance strategies for early detection of CWD in Montana (Montana Fish, Wildlife and Parks Department) and Shenandoah National Park (National Park Service), identifying potential disease risks posed by CWD to noncervid species such as bighorn sheep, and identifying environmental factors, like soil and plants, that may facilitate CWD transmission on the landscape.
The benefits of USGS research on CWD extend beyond wildlife management. For example, USGS scientists identified a novel enzyme from lichens with the ability to break down infectious prion protein that is being studied for its use in decontaminating human hospital environments in collaboration with an industry partner. Efforts will continue to focus on improving diagnostic testing platforms in collaboration with the U.S. Food and Drug Administration, providing surveillance and modeling technical assistance to a long-term CWD study carried out by the Wisconsin Department of Natural Resources, developing modeling techniques for predicting CWD growth within free-ranging cervid populations and forecasting disease spread in regions of interest, and continued identification and development of novel anti-prion compounds and processes to disrupt disease transmission cycles.
In addition to research, the NWHC also conducts numerous communications and outreach activities and products, such as fact sheets, briefings, media interviews, and presentations, on both a national and international scale.
To learn more about Chronic Wasting Disease, see our fact sheet - Chronic Wasting Disease: Status, Science, and Management Support by the U.S. Geological Survey.
To learn more about the plan for assisting states, federal agencies, and tribes in managing chronic wasting disease in wild and captive cervids, see - Federal Plan for Assisting States, Federal Agencies, and Tribes 2002.
Access up-to-date maps of the expanding distribution of chronic wasting disease.
- Science
Below are other science projects associated with this project.
- Multimedia
Below are multimedia items associated with chronic wasting disease.
- Publications
Below are publications about chronic wasting disease.
Chronic wasting disease—Status, science, and management support by the U.S. Geological Survey
The U.S. Geological Survey (USGS) investigates chronic wasting disease (CWD) at multiple science centers and cooperative research units across the Nation and supports the management of CWD through science-based strategies. CWD research conducted by USGS scientists has three strategies: (1) to understand the biology, ecology, and causes and distribution of CWD; (2) to assess and predict the spreadAuthorsChristina M. Carlson, M. Camille Hopkins, Natalie T. Nguyen, Bryan J. Richards, Daniel P. Walsh, W. David WalterFilter Total Items: 47Using auxiliary information to improve wildlife disease surveillance when infected animals are not detected: A Bayesian approach
There are numerous situations in which it is important to determine whether a particular disease of interest is present in a free-ranging wildlife population. However adequate disease surveillance can be labor-intensive and expensive and thus there is substantial motivation to conduct it as efficiently as possible. Surveillance is often based on the assumption of a simple random sample, but this cAuthorsDennis M. Heisey, Christopher S. Jennelle, Robin E. Russell, Daniel P. WalshUsing landscape epidemiological models to understand the distribution of chronic wasting disease in the Midwestern USA
Animal movement across the landscape plays a critical role in the ecology of infectious wildlife diseases. Dispersing animals can spread pathogens between infected areas and naïve populations. While tracking free-ranging animals over the geographic scales relevant to landscape-level disease management is challenging, landscape features that influence gene flow among wildlife populations may also iAuthorsStacie J. Robinson, Michael D. Samuel, Robert E. Rolley, Paul SheltonIn vitro prion protein conversion suggests risk of bighorn sheep (Ovis canadensis) to transmissible spongiform encephalopathies
Background: Transmissible spongiform encephalopathies (TSEs) affect both domestic sheep (scrapie) and captive and free-ranging cervids (chronic wasting disease; CWD). The geographical range of bighorn sheep (Ovis canadensis; BHS) overlaps with states or provinces that have contained scrapie-positive sheep or goats and areas with present epizootics of CWD in cervids. No TSEs have been documented inAuthorsChristopher J. Johnson, A.R. Morawski, C.M. Carlson, H. ChangAssociation mapping of genetic risk factors for chronic wasting disease in wild deer
Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy affecting North American cervids. We assessed the feasibility of association mapping CWD genetic risk factors in wild white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) using a panel of bovine microsatellite markers from three homologous deer linkage groups predicted to contain candidate geAuthorsTomomi Matsumoto, Michael D. Samuel, Trent Bollinger, Margo Pybus, David W. ColtmanEvaluating spatial overlap and relatedness of white-tailed deer in a chronic wasting disease management zone
Wildlife disease transmission, at a local scale, can occur from interactions between infected and susceptible conspecifics or from a contaminated environment. Thus, the degree of spatial overlap and rate of contact among deer is likely to impact both direct and indirect transmission of infectious diseases such chronic wasting disease (CWD) or bovine tuberculosis. We identified a strong relationshiAuthorsMichael D. Samuel, Seth B. Magle, Timothy R. Van Deelen, Stacie J. Robinson, Nancy E. MathewsDeer density and disease prevalence influence transmission of Chronic Wasting Disease in White-tailed Deer
Host-parasite dynamics and strategies for managing infectious diseases of wildlife depend on the functional relationship between disease transmission rates and host density. However, the disease transmission function is rarely known for free-living wildlife, leading to uncertainty regarding the impacts of diseases on host populations and effective control actions. We evaluated the influence of deeAuthorsMichael D. Samuel, Bryan J. Richards, Daniel J. Storm, Robert E. Rolley, Paul Shelton, Nicholas S. Keuler, Timothy R. Van DeelenEffects of chronic wasting disease on reproduction and fawn harvest vulnerability in Wisconsin white-tailed deer
Chronic wasting disease (CWD) is a fatal, transmissible spongiform encephalopathy that affects free-ranging and captive North American cervids. Although the impacts of CWD on cervid survival have been documented, little is known about the disease impacts on reproduction and recruitment. We used genetic methods and harvest data (2002–04) to reconstruct parentage for a cohort of white-tailed deer (OAuthorsJulie A. Blanchong, Daniel A. Grear, Byron V. Weckworth, Delwyn P. Keane, Kim T. Scribner, Michael D. SamuelPrion protein degradation by lichens of the genus Cladonia
It has recently been discovered that lichens contain a serine protease capable of degrading the pathogenic prion protein, the etiological agent of prion diseases such as sheep scrapie and cervid chronic wasting disease. Limited methods are available to degrade or inactivate prion disease agents, especially in the environment, and lichens or their serine protease could prove important for managemenAuthorsJames P. Bennett, Cynthia M. Rodriguez, Christopher J. JohnsonThe role of genetics in chronic wasting disease of North American cervids
Chronic wasting disease (CWD) is a major concern for the management of North American cervid populations. This fatal prion disease has led to declines in populations which have high CWD prevalence and areas with both high and low infection rates have experienced economic losses in wildlife recreation and fears of potential spill-over into livestock or humans. Research from human and veterinary medAuthorsStacie J. Robinson, Michael D. Samuel, Katherine O'Rourke, Chad J. JohnsonEmerging prion disease drives host selection in a wildlife population
Infectious diseases are increasingly recognized as an important force driving population dynamics, conservation biology, and natural selection in wildlife populations. Infectious agents have been implicated in the decline of small or endangered populations and may act to constrain population size, distribution, growth rates, or migration patterns. Further, diseases may provide selective pressuresAuthorsStacie J. Robinson, Michael D. Samuel, Chad J. Johnson, Marie Adams, Debbie I. McKenzieEnhanced surveillance strategies for detecting and monitoring chronic wasting disease in free-ranging cervids
The purpose of this document is to provide wildlife management agencies with the foundation upon which they can build scientifically rigorous and cost-effective surveillance and monitoring programs for chronic wasting disease (CWD) or refine their existing programs. The first chapter provides an overview of potential demographic and spatial risk factors of susceptible wildlife populations that mayHighly efficient amplification of chronic wasting disease agent by protein misfolding cyclical amplification with beads (PMCAb)
Protein misfolding cyclic amplification (PMCA) has emerged as an important technique for detecting low levels of pathogenic prion protein in biological samples. The method exploits the ability of the pathogenic prion protein to convert the normal prion protein to a proteinase K-resistant conformation. Inclusion of Teflon® beads in the PMCA reaction (PMCAb) has been previously shown to increase theAuthorsChad J. Johnson, Judd M. Aiken, Debbie McKenzie, Michael D. Samuel, Joel A. Pedersen - News
Below are news stories about chronic wasting disease.
- FAQ
Below are FAQs about chronic wasting disease.