Chronic Wasting Disease report incites sensational media response

In 2022, a 72-year old Wyoming hunter with a penchant for venison was suddenly beset by bouts of confusion and aggression, which later proved to be the symptoms of a central nervous system disorder known as Creutzfeldt-Jakob disease, or CJD, which took the man's life.

Shortly after, another hunter from the same community also died of CJD, and when it became known that both men had a history of consuming meat from deer populations afflicted by Chronic Wasting Disease (CWD), a cervid-specific neurological disease, it raised red flags with neurologists.

Because both CWD and CJD are the result of misfolded proteins known as prions, some experts feared the hunters had contracted CWD after consuming infected meat–which would mark the first known deer-to-human contraction since the disease was first recorded in 1967.

A team of neurologists set out in search of answers, but last week published findings that we’re inconclusive.

“Although causation remains unproven, this cluster emphasizes the need for further investigation into the potential risks of consuming CWD-infected deer and its implications for public health,” according to a report issued from journal Neurology.

And yet, even as the findings were less than compelling, outlets pounced on the story with sensational headlines that may have created unnecessary anxiety among sportsmen. Sault News ran a story titled “Death of 2 hunters in US raises fear of ‘zombie deer.’ The Daily Mail’s online version went further, saying, “Two hunters 'become first Americans to die from ZOMBIE DEER disease.’”

Wildlife biologists in Wyoming say those accounts are overblown.

“Definitely some of the headlines kind of seemed a little bit more fear mongering,” said Wyoming Game and Fish Wildlife Disease Specialist Jessica Jennings “I think people are getting concerned about it, but it's a report with pretty sparse information.”

Jennings says the report lacks critical information about the health history of the individuals, and other contributing factors that could have led to CJD. Nor did the researchers conduct specific prion protein analysis, which is essential in establishing a link. The report’s authors could not be reached for comment.

“I think it leads to more questions than answers,” Jennings said of the report.

Prion diseases are normally species specific, but concerns over “jumping” were elevated with the discovery of the transmissible Mad Cow Disease, a prion-based neurological disease that spread to humans. Elsewhere studies using primates and mice have shown that cross-species CJD is possible.

Even as the journal Neurology report fails to establish a link, Jennings and other biologists agree the risk that CWD may “jump” to humans is real, and that more research is needed as the disease increases in herds across the continent.

The journal Neurology report comes just weeks after the release of WGF’s annual “CWD Surveillance Report,” which shows the disease has increased in mule deer, white-tailed deer and elk state-wide, using as a reference hunter-harvested, adult male animals.

The prevalence was especially high in central Wyoming’s Project mule deer herd, where 65% of hunter-harvest males tested positive for CWD. Other high prevalence rates showed up in the Greybull River herd, with 46.2%, and the Shoshone River herd at 39.%

First discovered in southeast Wyoming in 1985, the surveillance effort highlights the disease's westward spread, and this year was detected in three new deer hunt areas, four new elk hunt areas, and a national park. Although, Jennings said increased prevalence also reflects the growth of the program itself, which has expanded to hitherto monitored cervid herds. Still, the data speaks for itself.

“This raises concern that this disease is becoming established in feed ground utilized populations and it raises questions about how this may affect deer and elk populations in the future,” Game and Fish says of the surveillance findings.

In response, local herd managers are working on CWD management plans that may involve extending hunting seasons, or encouraging hunters to target specific herd demographics, according to Jennings.

This story was published on April 23, 2024.