After decades, chronic wasting disease has reached Idaho
Idaho Fish and Game announced Nov. 17 that chronic wasting disease has reached Idaho’s deer population. The disease attacks the brain and nervous system of deer, elk, reindeer and moose, and is always fatal.
Tracy Nichols is a science officer with the United State Department of Agriculture’s APHIS Veterinary Services Service Health Program. She said it’s very likely the two animals that tested positive are not the first in the state to catch the disease.
“It doesn't just stay in one spot,” she said. “So it's hard to say how far it's gotten at this point.”
CWD, as it’s often called, was found in north-central Idaho’s hunting district 14, near the town of Lucile. It’s not caused by a virus or bacteria. The disease occurs because proteins in the body malfunction, folding over. Those proteins don’t impact the animal’s body, but head for the brain.
“At the very end of the disease process, it'll start affecting motor activities of the animals,” Nichols said. “However, a lot of animals never really get that far — something else kills them before they actually present as symptomatic or clinical.”
The infection spreads via excreted bodily fluids. It’s extremely difficult to contain because it can survive outside an animal’s body for years — maybe decades — just waiting for another to come along and pick it up.
It only affects cervids: deer, elk, reindeer and moose, though some studies have shown the disease can jump to monkeys via direct contact with infected deer and elk, or consumption of meat from infected animals.
The disease was discovered in Colorado in the late 1960s and has been in Wyoming and Montana for decades. The fact that it just now reached Idaho is little more than luck.
U.S. Geological Survey biologist Bryan Richards said Idaho officials have a good response plan, but will need help to control the spread.
“It makes a lot of sense to reach out to hunters and try and work with them to get more samples to try and figure out, ‘Are you at the center of an outbreak? Are you at the edge of an outbreak?” Richards said.
Idaho Fish and Game Commissioners will meet Nov. 22 to discuss management tactics, including an emergency hunt for sampling purposes.
Richards said research into curbing the disease with potential vaccines has been in progress for years, but even if a successful vaccine was developed, the logistical challenges of getting it into wildlife across 27 states and multiple Canadian provinces with confirmed outbreaks are numerous.
“There's also groups that are working on genetic resistance or reduced susceptibility to disease,” Richards said. “But again, as I see a limitation there, even if we could identify a genotype of deer with reduced susceptibility to CWD, how do we get it out there in the landscape?”
The Centers for Disease Control strongly urges sportsmen to get carcasses tested if hunting in areas where CWD has been found and not eat venison from CWD-positive animals even though there is no evidence yet the disease can spread to humans.
That recommendation may be simply out of an abundance of caution, but Richards said ‘the ick factor’ as CWD spreads could likely lead to long-term changes in hunting big game.