Scientists have raised concerns that “zombie deer disease,” also called chronic wasting disease (CWD), is spreading. The first reported cases were detected through routine monitoring of park wildlife and were discovered in deer living in the national battlefields of Antietam and Monocacy.
According to the CDC, CWD is a prion disease that has been found in North America, Norway, Canada, and South Korea. While not airborne in viral spread, scientists believe abnormal proteins called prions are spread through exposure to bodily fluids from an infected animal.
Once contracted, the abnormal proteins create a folding of neurological prions, resulting in a progressive loss of the animal’s ability to function. CWD has no known vaccine and is fatal once contracted. CWD can infect elk, moose, deer and reindeer.
The disease can be present and dormant for up to two years post-infection, raising concern over human transmission risk. While no human infection cases have been reported, several studies show a positive transmission risk to primates through the consumption of infected meat.
An ongoing study by CSTE continues to evaluate meat-related transmission risks, recently demonstrating a positive transmission to primates through consumption of meat from asymptomatic animals.
USDA Animal and Plant Health Inspection Service (APHIS) has worked with multiple local, state, and federal officials to test, track, and limit the spread of CWD from the first reported cases in the late 1990s.
Control measures include nationwide APHIS-certified testing laboratories and proper culling and disposal of infected animals. The Department of Natural Resources (DNR) aids in tracking the infected deer population through the testing of legally-hunted game.
Recently, Minnesota released CWD numbers for the end of the state’s hunting season, noting that CWD was primarily found in areas previously known to be at risk for contamination, according to the state’s DNR website. The study emphasizes the positive impact hunters can have on tracking and limiting CWD spread.
“Our fall surveillance efforts detected a CWD positive deer in one new deer permit area, while all other positive cases were found within existing CWD management zones where we have confirmed the disease previously,” Erik Hildebrand, wildlife health supervisor, said. “We greatly appreciate hunters’ help monitoring these areas.”
These findings suggest that CWD may spread slowly in the natural environment. Wildlife officials have also begun testing “scrapes,” which are social areas where bucks are known to congregate. Many deer will use the same scrape, increasing the risk of infection through exposure to other animal’s saliva and urine.
Scrapes that return positive tests may be the key to detecting and eliminating CWD from wildlife populations before infection spreads.
Earlier this month, new wildlife areas in Mississippi were marked as CWD areas following the culling of a deer who returned a positive test, according to Clarion Ledger.
“One of the really fascinating things about this is the scrape testing,” Russ Walsh, the chief of staff for Mississippi’s Department of Wildlife, Fisheries and Parks, stated. “There were scrapes sampled in Claiborne County last year and prions were detected in the scrapes.”
Symptoms of CWD include animals that exhibit severe weight loss, stumbling, staggering, and drooling. Individuals who witness deer exhibiting these signs are encouraged to contact their local Department of Natural Resources division for reporting.
