Does Chronic Wasting Disease Infect People? Research shows that this is not the case

Reading the chronic wasting headlines from April this year, you may be convinced that “zombie deer disease” has crossed the species barrier and is now killing deer hunters. But those fast-paced news stories were more the result of sloppy reporting than any new scientific development. Recent research published in the June issue of Emerging infectious diseases found that CWD prions fail to infect human brain tissue. This study supports years of previous research that has reached similar conclusions.

If you have a scientific background, you can delve into the details of the new research here. If not, here’s what you need to know.

Understanding the recent research

In 2022 and 2023, a research team from the National Institutes of Health directly exposed healthy human brain organoids to high concentrations of CWD prions from white-tailed deer, mule deer, and elk. According to the NIH, these are these organoids are a type of human brain cells that have been incubated in a controlled laboratory environment and are currently the closest available tissue to the human brain that can be used for this type of testing.

“Human brain organoids are small balls of human brain cells ranging in size from a poppy seed to a pea… The organization, structure, and electrical signaling of brain organoids are similar to brain tissue,” says an NIH press release.

After seven days of exposure, these organoids were monitored for up to six months. No one ever became infected with CWD.

“The data presented in this study show that, despite weeks of exposure to CWD prions with high infectivity and the ability to become easily infected with CJD prions, [human cerebral organoids] were unable to spread CWD prions,” the study says. “This finding indicates that, even after direct exposure of human central nervous system tissues to CWD prions, there is a significant resistance or barrier to the spread of infection.”

Interestingly, organoids exposed to Creutzfeldt-Jakob disease (a prion disease linked to CWD) quickly became infected under the same laboratory conditions, according to ScienceNews.

The takeaway? There is a substantial species barrier that prevents CWD from infecting humans.

“This was a model that could really help us determine whether or not it was a real risk,” said Bradley Groveman, a biologist at the NIH Rocky Mountain Laboratories. ScienceNews.

Why the Health Fear of “Zombie Deer”?

This recent study should help ease the fears of deer hunters following the study that went viral in April when the Daily email walked one News story headlined: “Two hunters ‘become first Americans to die from ZOMBIE DEER disease’ after eating contaminated deer meat”

That story, plus one Field and current news story published on Yahoo News before both days’ taping spawned a barrage of related stories regional newspapers And television stations. These articles varied in their level of panic, but most at least hinted at the idea that CWD had crossed the species barrier for humans.

However, Living outside contributor Katie Hill reported that the original source for these stories was not a scientific study at all, but a “scientific summary presented at the 2024 annual meeting of the American Academy of Neurology and reprinted in Neurology.”

The research summary provides an overview of a case in which two hunting friends died in 2022 from sporadic Creutzfeldt-Jakob disease. The men ate deer meat from a deer population known to have CWD. Because sporadic CJD is so rare, the abstract questions whether the two men could actually have been infected with CWD. But the summary does not say where the men hunted or whether the deer they ate venison from ever tested positive for CWD.

“After a conversation with [one of the authors] Dr. Sarah Horn, she told us the information did not come from a study, it was a poster presentation of a case report presented at the AAN annual meeting,” Eileen Teves, UT Health San Antonio public relations and media relations specialist, told me . Living outside in an emailed statement. “The conclusion from that presentation was that there have been no proven cases of transmission to date.”

How hunters should think about CWD

Any health professional trained on the subject will tell you that wild venison is one of the healthiest forms of red meat available. Remember, there is still no known case of CWD infecting a human.

But this does not mean that CWD will do the same never infect people. A new strain of CWD prion could emerge that could be more dangerous to humans. There are currently at least five known prion strains that can cause chronic wasting disease in cervids. Moreover, according to ScienceNews, “Brain organoids are not a perfect mimic of the real thing and may lack properties that would make them susceptible to infection.”

“I don’t think we’ll ever be able to turn around and say something.” [human infection] is impossible,” Cathryn Haigh, a cell biologist also at Rocky Mountain Laboratories, told the outlet.

The best thing hunters can do is stay informed about chronic wasting diseases, have their venison tested if it comes from a CWD-positive herd or is in an area where CWD testing is available, and follow local and interstate regulations to prevent the spread of the disease. . And deer hunters must continue to hunt deer because in many ways we are the first defense in controlling the disease and tracking its spread among wild deer.