Allowing Infected Deer Into Food System Could Pose Risk to Public, Experts Say

Experts are warning about the risks associated with Chronic Wasting Disease, or CWD, which affects deer breeds and can lead to a potentially disastrous infection throughout the animal's population. (Jeff J. Mitchell/Getty Images)

The Canadian Food Inspection Agency’s decision to allow meat from farms with disease-infected deer herds to enter the Canadian market could lead to potential risks for humans, multiple experts say.

Chronic Wasting Disease—commonly abbreviated as CWD—is a fatal infection that affects the central nervous system of cervids such as deer, moose, elk, and caribou. It’s usually found in adult animals, and is caused by misfolded proteins in their system called “prions” that can then be transmitted through bodily fluids and organic matter like soil.

Affected deer can have difficulty with regular movement, suffer rapid weight loss, and experience changes in behaviour like frequent trembling or salivating.

Although CWD hasn’t been proven to affect humans in any way, there’s evidence that it can remain infectious in the environment, and it’s also capable of heavily affecting the balance of natural ecosystems since cases always end in death. Humans are generally warned against consuming deer meat that comes from a herd infected with the disease as a safety precaution.

The CFIA website names CWD as a reportable disease in Canada under the Health of Animals Act, and all suspected cases are required to be reported to the agency.

Although the CFIA has confirmed that all infected deer prior to 2014 were put down, meat from 21 herds where the disease was found has still ended up in Canada’s food system—and experts say that this could pose an unnecessary risk to Canadians.

“This is a serious threat to Alberta, to Canada, to our economy, to our agriculture industry, to our wildlife and to human health,” Doctor David Swann told CBC News. “It’s just stunning to me that we’ve gone 10 years since the BSE [mad cow] crisis and haven’t recognized an identical problem now with the same kind of illness in deer, and we’re consuming deer without regard to our safety and health.”

Swann said that the disease is “easily transmitted,” and that he can’t understand why the provincial and federal governments aren’t taking the risks more seriously. Even though CWD hasn’t been shown to be able to transmit to humans, Swann said, it’s still possible that it could be lying dormant before finally doing just that.

The doctor told CBC that the situation could lead to a “devastating pandemic,” and that no one should consider consuming deer meat until it’s been tested and proven to be completely CWD-free.

A map shows the spread in occurrences of Chronic Wasting Disease across North America using data until up to Aug. 2, 2019. (USGS National Wildlife Health Center)

Neil Cashman, a medical professor at the University of British Columbia, agrees with Swann. In an interview with Global News, he said that putting meat from an infected herd on the market was like “playing with fire.”

Cashman specializes in neurodegenerative diseases like CWD, and also holds advanced knowledge on the prion proteins that cause it. “With all this knowledge about how wily prions are, how long they last in the environment, how resistant they are to destruction and degradation, it really behooves us to cut down on potential exposure to CWD,” he said.

In June, a group of medical professionals sent a letter to Prime Minister Justin Trudeau as well as several federal ministers, urgently calling for action to prevent further spread of the highly contagious disease. The letter called CWD an “epidemic” and outlined several possible courses of action that the government could take, including containing its geographic movement, implementing mandatory testing for all animals in CWD-affected areas, and developing a plan to combat the possibility of future human infection.

The letter was signed by 34 health and medical professionals who “implore [the government] to recognize the dire nature of this epidemic, of your acknowledgement of the public trust, and the responsibilities of your office.”

“We stand in support of your announcement of the government of Canada’s urgent undertaking of all necessary actions to meet these challenges and protect Canadian interests,” the letter said.

The disease is also currently being researched by multiple independent organizations, including SING Canada, a summer internship program for Indigenous peoples that focuses on genomics.