A pressing concern for hunters nationwide, deer and elk populations are being threatened by a disease known as “zombie deer disease.” This disease’s medical term is chronic wasting disease and is comparable to bovine spongiform encephalopathy, or mad cow disease. It is continuing to spread, and cases have now been reported in 24 states as of January 2019.
This disease, like mad cow disease, is incurable once contracted and thus is fatal to all animals that are infected. It is a prion disease, meaning that it is caused by proteins that attack the brain, and it is transmitted through bodily fluids. As the disease progresses, the brain becomes increasingly porous, and it will eventually cause extreme weight loss, stumbling and confusion. Many animals will not even live to develop any symptoms, and there have been many cases in which hunters have shot deer that appeared perfectly healthy, but through testing have found that the deer had CWD. Furthermore, the name “zombie deer disease” is somewhat misleading, as the degeneration of the brain does not generally make deer any more aggressive but merely confused. Lindsay Thomas Jr., the director of communications for the Quality Deer Management Association, has said that the disease would not turn an animal into the conventional horrifying zombie but rather give it a condition similar to dementia where that the brain is deteriorating and causing confusion and erratic behavior. This may cause infected deer to approach people more readily than healthy deer, but according to Thomas, there is no reason for hunters to avoid hunting due to fear of zombie deer.
Mad cow disease affects exclusively bovine. One type of it is transmittable to humans who eat the affected animal, but the disease manifests itself differently in humans and is known as variant Creutzfeldt-Jakob disease. This disease is incurable and fatal to humans, but only four cases have ever been reported, with all of them having origins speculated to be outside of the US.
The concern of the disease being transmittable to humans is now being considered for CWD as Michael Osterholm, the director of the Center for Infectious Disease Research at the U of M, told Minnesota law makers that he is concerned with the possibility of the disease spreading to people. He said that it is probable that cases of the disease spreading to humans through consumption of contaminated meat will arise in coming years. He also predicted that the number of cases in which the disease is transmitted to humans will be “substantial and will not be isolated events.” This statistic is alarming for a state that harvests nearly 200,000 deer annually. Although Minnesota is currently not among the 24 states with recorded cases of CWD, the rapid growth could potentially mean the spread of the disease to our state’s deer populations.
According to a 2017 report by the Alliance of Public Wildlife, hunters consume between 7,000 and 15,000 CWD-infected animals per year. This statistic provokes fear when coupled with the words of Dr. Osterholm on the potential for the disease spreading to humans. However, no cases have been reported of the disease manifesting itself within humans. Many states allow free testing for CWD on harvested deer and even have testing centers available for hunters. Additionally, the CDC has recommended that hunters refrain from harvesting deer that are sick, act strangely, or are found dead. It is also recommended that hunters wear latex gloves while field dressing their deer in order to avoid contact with bodily fluids.
Although no humans have contracted CWD, experts on the spread of diseases agree on the recommendations of the CDC and hope that the current precautionary measures are sufficient for keeping people safe from the deadly disease.