Zombie Deer Disease? Is it Real? Is it Contagious to Humans?

Posted in Food Safety,Our Blog,Outbreaks & Recalls on February 20, 2019

Zombie deer?  Zombie Deer Disease?  Is that really a thing?  Sounds like something from the latest M. Night Shyamalan movie.  Sadly, no.  This is real problem for wild life.  And it isn’t just limited to deer.  Moose and elk can also find themselves victim to this disease. Wild game hunters everywhere are worrying that their pray may not be so edible these days. Well, despair not. Here’s what you need to know about Zombie Deer Disease.

They call it colloquially Zombie Deer Disease because of how infected animals look and behave, but it is officially known as Chronic Wasting Disease, or CWD.  CWD is a prion disease (a type of transmissible spongiform encephalopathy that primarily affects and is transmitted by the brain).

CWD has been found in animals in North America, Norway, and South Korea.  Symptoms make these poor animals look, well, like zombies.  They have drastic weight loss (that is where they come up with the name wasting disease), can be seen stumbling, appearing listless, and other neurological symptoms.  It could take over a year before symptoms begin to show and some infected animals may die without ever developing the disease.  There is no treatment or vaccine available at this time.  Additional research is being done to learn more about this disease and how it might affect humans.

The Center for Disease Control and Prevention (CDC) says that there are no reported cases of this wasting disease in people, though they acknowledge there may be still a risk to some types of non-human primates – like monkeys.  Though the World Health Organization takes the risk of prion disease in humans very seriously and appropriate precautions should be taken to avoid risking human infection.  But more on that in a bit.

So now that we have established that Zombie Deer Disease or Chronic Wasting Disease is real.  Where can it be found?

Zombie Deer Disease Sightings and History

The latest CDC data as of January 2019 indicates elk, moose, and deer in South Korea, Norway, Finland, two providences in Canada, and at least 24 states in the continental United States including: Arkansas, Colorado, Illinois, Iowa, Kansas, Maryland, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Mexico, New York, North Dakota, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming.

That’s where we are now.  But how long has this disease been known about?  Research shows that the zombie deer disease has been identified as early as the late 1960’s when it was discovered in captive deer in Colorado.  It was seen and documented again in wild deer in 1981.  By the 1990’s the disease was reported around the Northern area of Colorado and Southern area of Wyoming.  Since 2000 it has spread and continues to spread to where it is today along the Midwest, Southwest, up to the East Coast.  The CDC indicates that the disease might be in other states as well, as there are many states that lack a strong animal surveillance system.  Expansion is evident.

Statistics of infection rate are scary.  In areas were the disease is established in free ranging deer, elk, and moose, about 10% of the population are affected.  In some cases that number is as high as 25%.  This number is much higher in affected captive deer populations with as much as 79% or nearly 4 out of 5 deer.

But how does the disease spread from animal to animal?  Are humans at risk?

How Zombie Deer Disease Spreads

Zombie Deer Disease is a prion disease.  Like other prion diseases, it can be spread through contact with a variety of bodily fluids, including feces, saliva, blood, and urine.  Infection can be transmitted through direct contact with infected fluids or through contaminated soil, food, or water.  The disease is quite contagious and spreads through deer and elk populations very quickly.

These fluids and harmful proteins resulting from the prion disease can hang out in the environment for a long time.  This allows the disease to continue to spread even after the infected animals have died.

Experiments in squirrel monkeys and laboratory mice genetically modified to carry some human genes have been performed.  These animals were able to be infected.  Other studies in macaques (a monkey, and the most genetically similar animal to humans) demonstrated that monkeys fed infected meat or brain tissue were infected.  While this does not definitively mean that it can transmit to humans there is a strong suggestion that it is possible.

Some deer may be infected without showing symptoms.  What about that meat?  Could meat from asymptomatic deer be infectious?  Turns out, yes.  Meat from asymptomatic deer fed to laboratory monkeys did in fact spread the disease.  This poses a bigger problem.

People who hunt deer, elk, and moose can take measures to avoid animals who appear sick.  But what can they do to protect themselves from animals who do not show any signs of the sickness?

Preventing Zombie Human Disease

Goal number 1 is preventing Zombie Deer Disease from transmitting to human populations and creating Zombie Human Disease.  I doubt people are going to break out in choreographed Thriller dancing with Michael Jackson impersonators or start craving human flesh like their cinematic counter parts.  Chronic Wasting Disease is a serious concern to humans, as the outcome is more than unknown but expected to be awful.

So what can be done?  We can start by educating hunters.

According to a CDC study of United States residents, nearly 20% of those surveyed indicated they had hunted deer or elk and more than two-thirds said they have eaten venison or elk meat.  With this in mind, combined with asymptomatic infection in many deer, the CDC recommends that hunters “strongly consider having those animals [in areas where CWD is known to be present] tested before eating the meat.”  Unfortunately, a negative test result is not a guarantee an animal is not infected, though it does considerably reduce the risk of exposure.

Hunters are urged to take additional steps to reduce risk of human exposure to Zombie Deer Disease or Chronic Wasting Disease.  Consider the following:

• Avoid Sick or Dead Animals – Do not shoot, handle, or eat meat from animals that are acting strangely or look sick. Do not handle or eat meat from animals found dead.
• Take Precautions When Field-Dressing Deer – Wear latex or rubber gloves to protect hands. Avoid handling organs – particularly brain and spinal cord tissues.  Do not use household knives or your normal kitchen utensils for field dressing.
• Check Local Listings – Check state wildlife and public health guidance where you are hunting to get recommendations about testing for Chronic Wasting Disease.
• Have Meat Tested – The CDC strongly considers having deer or elk tested for the disease prior to eating the meat.
• Commercial Processing Suggestion – If your deer meat is being processed with a commercial processor, ask if your animal can be processed individually to avoid cross-contamination with meat from other animals.
• If Test is Possible DO NOT EAT – If the animal tests positive for CWD, DO NOT EAT THE MEAT from that animal.

If Zombie Deer are known to be in your area, you can still enjoy venison in all its tasty glory.  Avoid the risk by taking the simple precautions and testing your meat before you eat it.  Once you are given the all clear, enjoy your sausage, deer roast, deer steaks, and whatever you enjoy best.

By: Heather Van Tassell, Contributing Writer (Non-Lawyer)