Chronic Wasting Disease |
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Chronic Wasting Disease (CWD) is a transmissible spongiform encephalopathy (TSE) affecting elk and deer (cervids) as well as moose, in North America. |
This degenerative neurological illness has affected both farmed and wild cervids in the US, thus impacting the hunting and wildlife industries as well as domestic and international markets for farmed cervids and cervid products. APHIS' response to this disease includes support of surveillance in both farmed and wild populations and assistance to State agencies for quarantine of affected animals and premises, humane euthanasia, and testing affected and exposed animals. In addition APHIS provides indemnity to animal owners for the value of positive and exposed animals euthanized in disease control efforts. A Herd Certification Program (HCP) is being developed by APHIS in coordination with states, the farmed cervid industry, and the US Animal Health Association (USAHA) to support this effort. APHIS also has assisted, and continues to assist, States with CWD surveillance and management in wild cervid populations. Finally, APHIS is working with the US Department of Interior, Tribes, and States to implement an interagency, national plan to help manage CWD in captive and wild cervids. For more detailed information on CWD and APHIS response, read the fact sheets listed above. See also the VS approach to free-ranging wildlife.
Information and Services
CWD History
Frequently Asked Questions (pdf 96kb)
Preguntas y Respuestas (pdf 64kb)
CWD Diagnostics
APHIS Herd Certification Program
Interagency National Plan
VS CWD QuickPlace Login
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The "gold standard" diagnostic test for CWD is the Immunohistochemistry (IHC) test performed on the obex tissue of the brain (right) or specific lymphoid tissues. |
IHC testing is a method utilizing antibody based staining which is evaluated using light microscopy. This test is both sensitive and specific. In addition, the microscopic methods used to detect positive staining also allow confimation that the correct tissue and location within the tissue are present to detect the earliest accumulations of the prion agent. Other diagnostic tests utilizing enzyme-linked immunosorbent assay (ELISA) and other technologies that allow more rapid testing of larger numbers of samples have been, and continue to be, developed. Several test kits using ELISA and other technologies have recently been licensed by USDA's Center for Veterinary Biologics for CWD diagnosis in wild elk and deer. CWD testing can only be performed by approved laboratories that are part of the USDA Contract Laboratory system. A tonsillar biopsy (live-animal) test has been developed by researchers in Colorado and appears promising for certain CWD disease control or management situations. This technique utilizes the current IHC testing technologies described above.
Click here to view a map (pdf 48kb) showing the locations of the 26 USDA Contract laboratories for CWD, or view the National Veterinary Services Laboratories listing of laboratories and contact points.
The Management Plan for Assisting States, Federal Agencies, and Tribes in Managing Chronic Wasting Disease (CWD) in Wild and Captive Cervids was developed by a task force including USDA, the US Department of Interior, Tribal, and State representatives at the request of Congress. This plan establishes a coordinated approach to performing research and management actions and for sharing information across geographic boundaries and agency jurisdictions. It includes information on communications, scientific and technical information dissemination, diagnostics, disease management, research, and surveillance. To read the Management Plan, click here (pdf 127kb).
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