Chronic Wasting Disease (CWD) has come to the fore front as possibly the largest threat to our tradition of deer hunting. According to the Center for Disease Control and Prevention (CDC), this disease is now present in 21 states and 164 counties of the United States as well as in Canada. Shown below is the current map as of October 2015.
CWD was first discovered in a captive mule deer in Colorado in the late 1960’s and found first in the wild population in 1981. In the past 36 years, it has now reached almost half of the states. It would appear that if it is not present in your state, it most likely will be in the not distant future.
What is CWD? It is easier to answer what it is not, than to describe what it is. CWD is not caused by a virus or a bacterium or any other common pathogen. According to the CDC, “CWD is a prion disease(https://www.cdc.gov/prions/index.html) that affects North American cervids (hoofed ruminant mammals, with males characteristically having antlers). The known natural hosts of CWD are mule deer, white-tailed deer, elk, and moose. CWD was first identified as a fatal wasting syndrome in captive mule deer in Colorado in the late 1960s and in the wild in 1981. It was recognized as a spongiform encephalopathy in 1978.”
What is a prion? The CDC describes it as follows: Prion diseases or transmissible spongiform encephalopathies (TSEs) are a family of rare progressive neurodegenerative disorders that affect both humans and animals. They are distinguished by long incubation periods, characteristic spongiform changes associated with neuronal loss, and a failure to induce inflammatory response.
The causative agents of TSEs are believed to be prions. The term “prions” refers to abnormal, pathogenic agents that are transmissible and are able to induce abnormal folding of specific normal cellular proteins called prion proteins that are found most abundantly in the brain. The functions of these normal prion proteins are still not completely understood. The abnormal folding of the prion proteins leads to brain damage and the characteristic signs and symptoms of the disease. Prion diseases are usually rapidly progressive and always fatal.
There are several TSE’s that affect both humans and animals but there is little evidence that it is easily transmittable across species. In humans, the most common is Creutzfeldt – Jakob disease (CDJ) and its variants. In animals, the most well-known, besides CWD, is Mad Cow Disease (Bovine Spongiform Encephalopathy). There is also a form that infects mink, felines and sheep.
In this writers’ opinion, if it were easily transmittable there should be a corresponding spike in both cows and humans as CWD has spread throughout the United States. There has been no such spike. Since deer move freely among cattle and even share salt and mineral sources as well as feed and browse, cattle should be getting infected. They are not. The last reported case of Mad Cow Disease was in February 2015 in Alberta, Canada. From 1993 to February 2015, only 24 cases were found: 20 in Canada and 4 in the United States. The same is true with human infection. From 1996 through 2014, only 4 cases of CJD were reported in the U.S. There were 229 cases world wide and 177 of those were in the U.K.
Bottom Line: At this time, it does not appear to be a major health risk to humans. However, the Missouri Department of Conservation and other agencies recommend not coming in contact with the brain or spinal fluid of a deer. If there is any question as to the health of a deer that has been harvested, report it to your wildlife agency and have it tested prior to consumption. Do everything you can to stop the spread of this disease. Don’t concentrate animals by feeding if you are in an area close to known infected areas. Many states are now restricting feeding and using mineral licks so know your state or county regulations. Dispose of carcasses properly after processing. It is never a good idea to transport a carcass to another state or county, particularly the spine and brain. Millions of people eat beef and venison every year with no health problems. Don’t let the fear of this disease impact your love of hunting and consuming wild game.
In my opinion, the health benefits of wild game outweigh the very slim chance of exposure. Wild game is lean, clean, has no artificial flavors, contains no antibiotics or added hormone and is GMO free. On top of that it is just plain tasty. Enjoy!
Source: Center for Disease Control and Prevention web site, https://www.cdc.gov/prions/cwd/ and Missouri Department of Conservation website, https://mdc.mo.gov/