Zombie Deer Virus – something to keep a watch for

Janet Moje
Zombie Deer Virus – something to keep a watch for

Don’t believe it? Sadly, it’s true. This always fatal disease is known as Chronic Wasting Disease or CWD. It is currently active in 25 US states and two provinces, Alberta and Saskatchewan. It has a long incubation period and no symptoms until the disease is quite advanced. There is currently no test for live animals, only dead ones. Much is unknown about the disease but recent breakthroughs believe it to be caused by bacteria spread through bodily fluids - blood, saliva, urine and feces. It is estimated that it could infect as many as 1 in 4 wild deer in the U.S.A.

The first cases in Canada were found in Saskatchewan on a commercial deer operation in 1980s. The infection was traced back to imported deer from South Dakota. There are 327 confirmed cases in deer for 2018. The first elk was detected on a Saskatchewan commercial elk farm in 1996, also traced back to an imported elk from the U.S.A. There are 34 confirmed cases of farmed elk in Canada in 2018. Since 2005, there have been a total of 919 cases. The Canadian Food Inspection Agency (CFIA) requires all farmed deer, elk and caribou to be tested before any part of the animal can enter the food chain but what about wild game? If a hunter doesn’t test their kill, how much higher are the numbers?

The advanced symptoms of the disease is drooling, excessive urination, stumbling, head tremors, drastic weight loss, retention of winter coat, and no signs of fear or aggression - a trance-like stance – hence the name ‘Zombie’. The disease creates holes or lesions on the brain, and stains brain and lymphoid tissues.

Last month, the Center for Disease Control (CDC) announced that the disease could be transferred to humans. Research has shown that monkeys that eat infected animals do become infected. Cattle, sheep, goats, ferrets, mink, and mice have been infected through inoculation, but there have been no known cases of cattle, sheep or goats contracting the disease from sharing infected pastures. It is being recommended that adequate fencing be used around farmed herds to lower possible exposure to wild herds.

Current controls are being employed through quarantine and depopulation of herds. Hunting and targeted removal of wild herds is being used in the U.S.A. because it is believed lowering deer densities will slow the spread of infection. But the long incubation period, no tests to diagnose live animals, and persistence in soils (up to three years) makes managing CWD difficult.

CFIA recommends to avoid contact with CWD infected animals. Do not consume high risk materials such as brain, spinal cord, and offal. Wear latex or rubber gloves when handling or dressing deer or elk from CWD areas, and thoroughly wash knives and other implements used to process carcasses.

World Health Organization recommends that humans not eat any part or product of any animal with CWD (venison, antler velvet) because risks are unknown.

A time-of-kill test is being developed and is projected to be available in a year. Vaccines for humans, deer and elk are expected to be produced in two years, and an oral or nasal vaccine in three years.