Chronic Wasting Disease

Chronic Wasting Disease, or CWD, is a transmissible spongiform encephalopathy related to mad cow disease (bovine spongiform encephalopathy) and is fatal. Its origin is unknown.

Eventually fatal and with no known treatment options, chronic wasting disease is especially concerning because it also contaminates the soil, where it is endemic. Although originally limited to north-central Colorado and southeast Wyoming, recent outbreaks in other states and expansion in Wyoming have heightened concern about the disease's spread because it could be a significant mortality factor for elk.

CWD is infectious and contagious. The disease is transmitted by animal-to-animal contact or through contact with a contaminated environment, but the exact mode of transmission is unknown. The dynamics of this disease in elk and deer populations are still not thoroughly understood. Transmission may be influenced by animal numbers, the time infected animals occupy a given space, and the amount of space occupied by infected animals. It may also be related to the density of susceptible hosts. The density of animal populations would likely play a role through faster and greater seeding of the environment with the prion agent and more animal-to-animal contact.

Chronic wasting disease has not been documented in elk wintering on the refuge, but the spread of chronic wasting disease to the Jackson elk herd is possible. If chronic wasting disease does become present in the herd, environmental contamination will become a major concern due to the disease's ability to persist in the environment for a long period of time, even after intensive efforts to eradicate it. Some precautionary measures, such as reducing densities and numbers of elk and increasing dispersion, could reduce the chance of major adverse impacts if the disease became established.

On November 21, 2018, the Wyoming Game & Fish Department's Wildlife Health Laboratory confirmed an adult buck mule deer from Grand Teton National Park tested positive for CWD. The news story describing the positive test result can be found here. As a result, the National Elk Refuge implemented disease response strategy actions as appropriate, including mandatory CWD sampling of all elk harvested for the remainder of the 2018 hunt season; increasing surveillance during all field operations to watch for animals displaying symptoms of CWD; euthanizing suspect animals; coordinating public outreach with state, federal, and local partners; and continuing to pursue carcass disposal options with community stakeholders. See related National Elk Refuge news story here.  

More information on CWD can be found on the following websites:

U.S. Geological Survey (USGS) National Wildlife Health Center
Chronic Wasting Disease Overview
What is chronic wasting disease?
What are the visual signs of chronic wasting disease?
What causes chronic wasting disease?
Distribution of chronic wasting disease in North America    

Wyoming Game and Fish Department
Chronic Wasting Disease in Wyoming Wildlife
Chronic Wasting Disease Interactive Map
Proper Carcass Disposal and Transport
Chronic Wasting Disease Testing
Chronic Wasting Disease Results 

Wyoming Department of Health
Information on Chronic Wasting Disease for Hunters 

Centers for Disease Control and Prevention
Chronic Wasting Disease 

2016 Chronic Wasting Disease Forum - Jackson, WY

The National Elk Refuge, along with State and Federal land and wildlife managers and other non-profit organizations, hosted a Chronic Wasting Disease (CWD) forum on Wednesday, December 7, 2016. The forum was dedicated to highlighting CWD research and management considerations. The goal of the event was to share current science-based information with the general public and all organizations concerned with the long-term health of area elk and deer populations. 

To better serve the public and accommodate those who were unable to attend, each of the sessions was recorded by nature and wildlife documentary filmmaker Shane Moore and is now available for viewing by clicking here. The link also provides speaker biographies and the published proceedings from the CWD forum.