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Chronic wasting disease (CWD) is a prion disease that affects deer, elk, reindeer, sika deer and moose. It has been found in some areas of North America, including Canada and the United States, Norway and South Korea. It may take over a year before an infected animal develops symptoms, which can include drastic weight loss (wasting), stumbling, listlessness and other neurologic symptoms. CWD can affect animals of all ages and some infected animals may die without ever developing the disease. CWD is fatal to animals and there are no treatments or vaccines.


*Deer with CWD

To date, there have been no reported cases of CWD infection in people. However, some animal studies suggest CWD poses a risk to certain types of non-human primates, like monkeys, that eat meat from CWD-infected animals or come in contact with brain or body fluids from infected deer or elk. These studies raise concerns that there may also be a risk to people. Since 1997, the World Health Organization has recommended that it is important to keep the agents of all known prion diseases from entering the human food chain.

Chronic wasting disease (CWD) is a disease of the nervous system in deer and elk that results in distinctive brain lesions. It continues to be a major issue for wildlife scientists throughout the Nation, and a key focus for research at the USGS National Wildlife Health Center (NWHC).


Understanding how the disease is transmitted among elk and deer, understanding the patterns of infection, and determining how infection rates differ according to age and sex of the animal.

Searching for indications of genetic resistance to CWD, and developing tools for understanding CWD epidemics.

Studying the role that infected deer carcasses play in CWD transmission and how feeding and baiting may affect transmission patterns.

Exploring the susceptibility of small mammals and their potential role in the transmission of CWD.


The NWHC continues to investigate CWD in Wisconsin and throughout the Nation. NWHC scientists provide general information, consultation, and assistance to state agencies. NWHC staff participate in the multi-agency CWD Science and Health Team and the Research Team, providing analyses and advice crucial to determining the distribution of the disease in and around the Midwest.

Through collaboration and research, NWHC scientists seek a better understanding of the dynamics of CWD in wild populations as it expands over different landscapes. Scientists at the NWHC are committed to the belief that collaboration with many different agencies is critical to understanding and controlling this disease.

Chronic Wasting Disease Quick FactCWD infects elk, white-tailed deer, and mule deer, but is not known to infect livestock or humans at the present time. No treatment is known and the disease is typically fatal.

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