Fear of Infection: Could chronic wasting disease make the jump to humans?
A deadly disease thought to mostly affect deer is now front and center in Michigan.
It’s called chronic wasting disease, or CWD, and there’s no known cure for it.
Now, there’s new concerns that CWD could eventually make the jump to humans.
A new preliminary study out of the Alberta Prion Research Institute at the University of Calgary shows researchers were able to transmit CWD to macaque monkeys by feeding them CWD-infected meat and injecting them with the disease.
Although the study has not been peer reviewed, it is raising concern among wildlife experts and researchers. As the Centers for Disease Control and Prevention points out, macaques are genetically closer to people when compared to other animals.
Michigan State University wildlife Professor William Porter said there are parallels in history revealing a potential for CWD to become a major problem for humans.
“We thought that mad cow disease would be limited to infecting only cattle,” Porter said, referring to the prion disease that caused sickness in overseas cattle throughout the 1990s. “But what we learned a decade ago was that more than 200 people died in Great Britain, after contracting mad cow disease from hamburgers they were eating or beef they were eating.”
Porter said the macaque study is enough to cause serious concern, even if the study has not been peer-reviewed.
“The qualification is that everything we know about this disease suggests caution,” he said.
Hunters in Michigan have been aware of CWD for years, even before the disease was found in Michigan deer.
Brandon Hammonds hunts regularly in Coldwater, Michigan, and said he has seen what CWD has done to deer populations in other states.
“States like Wisconsin have decimated miles and miles of area, basically culling deer to eradicate the disease,” Hammonds said. “Once a deer has it, it’s pretty much terminal.”
To help blunt the impact and potentially eliminate CWD from the state, Michigan’s Department of Natural Resources encourages hunters to submit heads of hunted deer to the DNR through various check stations established throughout the state.
Currently, it’s not mandatory to submit deer for testing, and Hammonds does not submit either.
“It’s one thing I’d like to see the state improve on – having multiple check stations and more convenient check stations for hunters,” he said.
Hammonds said one of the reasons he does not submit his deer for testing is that the deer he hunts do not display the known symptoms of CWD, such as excessive drooling, confusion or repetitive pacing.
However, Michigan’s state wildlife veterinarian, Kelly Straka, cautions those signs might not develop for months, meaning some deer killed and consumed might actually have CWD.
“I would say out of all the deer that have tested positive for CWD, only one has shown any clinical symptoms, otherwise they appeared to be normal," Straka said.
Hammonds noted that if he knew any of his venison came from animals infected with CWD, he would not eat it. He also notes that if CWD ever made the jump to humans, it would likely change the state’s hunting culture, noting that many hunt with the idea they will eat venison, and share the venison with family and friends.
“The community aspect of hunting here is awesome and I look forward to it every year,” he said, expressing worry that if CWD ever infected humans, many might stop hunting.
As a result of CWD, the CDC strongly recommends that hunters have their deer tested before consuming. The CDC also urges against eating meat from a CWD- infected animal.
Michigan DNR deer management specialist Chad Stewart said CWD has changed his job drastically in recent years, as he increasingly spends time trying to educate hunters about the disease.
“We’ve had a fairly intensive response since we first found it in Ingham and Clinton counties back in 2015,” he said.
According to the DNR, 57 deer in Michigan have tested positive for CWD since 2015, found in various counties, including Kent, Ionia, Clinton, Shiawassee, Eaton, Ingham, Mecosta, Montcalm, and parts of the Western Upper Peninsula.
“There’s a lot of effort now from the department and certainly my position has a priority in handling this disease to make sure it’s not spreading to the landscape to the best of our abilities,” Stewart said.
When asked what would happen to hunting in Michigan if it was proved that CWD could infect humans, Stewart didn’t mince words.
“That’s one thought I’ve had and I’ve tried to shove it to the back of my mind,” he said. “Because absolutely we rely on our hunters to manage deer in this state. … And if we take the consumptive piece away from hunters, I don’t know if they would continue to hunt that animal if there’s a risk they could contract the disease.”
Meanwhile, as Straka’s staff continues testing deer submitted for CWD, she is encouraging hunters to submit animals for testing, regardless of whether or not humans are directly impacted by CWD.
“It's so important for hunters to get their animals tested so we can better understand the expansion of the disease as it exists on our landscape,” she said. “My staff is working around the clock to figure out where this disease is and figure out the best way we can combat it.”
More information about the testing process is available on the DNR’s website.