What is chronic wasting disease (CWD)?

CWD is a fatal nervous system disease found in members of the deer family (cervids). The disease is much more common in deer, but is also found in moose and elk. CWD belongs to a group of diseases known as Transmissible Spongiform Encephalopathies (TSEs). This includes:

• mad cow disease, found in cattle
• scrapie, found in sheep and goats
• Creutzfeldt-Jakob disease (CJD), found in humans

CWD occurs in some parts of eastern Alberta, from Cold Lake south to the US border. It has also been found in wild game (cervids) in Saskatchewan, 25 states in the United States, Norway, and South Korea.

Does CWD infect people?

There is no direct evidence that CWD has ever been transmitted to humans like mad cow disease (as CJD). However, some research shows that CWD can be transmitted to primates closely related to humans by feeding them meat or brain tissue from deer and elk infected with CWD. As a result, health organizations, such as the Centers for Disease Control and Prevention, advise caution when eating meat from animals harvested from areas where CWD has been found.

What causes chronic wasting disease?

TSEs like chronic wasting disease and mad cow disease are caused by infectious proteins called prions (say “PREE-ons”). In CWD, these proteins are found in the brain, spinal cord, lymph nodes, spleen, and muscle tissue.

CWD disease is thought to be spread between animals by direct animal to animal contact, contact with saliva, urine, carcass parts, or feces from infected animals, and can even spread through soil that has been contaminated with any of the above tissues or fluids.

How can I lower the risk of chronic wasting disease?

Alberta Health recommends that any animals from the deer family harvested from areas where CWD has been found should be tested before any parts of the animal are eaten. A negative test result does not guarantee that the animal is not infected with the disease, but does make it less likely. A number of health organizations continue to gather evidence and evaluate any potential human health risk of CWD.

• Find out more about testing services for chronic wasting disease

Additional precautions include:

• Do not handle or eat meat from any animal that appears sick.
• Avoid eating the brain, spinal cord, spleen and lymph nodes of any harvested animal, as these tissues may have high prion concentrations if the animal is infected.
• Follow best practices for handling game animals
  • wear protective gloves
  • handle organs and nervous tissue as little as possible
  • wash hands with soap and water
  • disinfect instruments after handling carcasses
• If someone gives you deer meat, ask where it was harvested. If it was harvested in an area where CWD is found, ask if it was tested.
• If you have your wild game commercially processed, ask that your animal be processed individually, without meat from other animals being added.

Please note: restaurants that sell venison or other game meat get their meat from a farm. All of these animals are tested and must be shown to be negative for CWD before being sold. The risk of coming into contact with infected meat is therefore considered to be insignificant in these settings.

Latest information

The following health organizations are tracking and studying CWD. Their websites have the most up-to-date information about this disease.

• Canadian Food Inspection Agency (CFIA) answers questions about CWD, including the tracking, diagnosis, and the disease in deer animals.
• Alberta Environment and Parks provides information on Alberta’s surveillance and testing program for CWD.
• Alberta Agriculture and Forestry provides further information on CWD in relation to deer game farms.
• Centers for Disease Control and Prevention provides information about how to lower the risk of human exposure to CWD.