Scientists concerned about potential COVID spread from infected deer

Widespread coronavirus infections have been detected in Iowa's white-tailed deer, according to a peer-reviewed study published Tuesday.

Why it matters: It's the first widespread natural infection of the virus documented in a wild animal species, according to researchers.

• Scientists worry the disease could mutate in animals and spread back to humans.

State of play: Scientists from Penn State University partnered with the Iowa Department of Natural Resources to examine hundreds of deer tissue samples collected as part of the department's chronic wasting disease surveillance.

What they found: More than a third of all samples collected between April 2020 and January 2021 were positive for coronavirus and the levels coincided with infection rates among humans in Iowa.

• More than 80% of samples contained the virus following the November 2020 peak of human cases in the state.

Of note: Deer experimentally infected with COVID didn't show symptoms, but it remains unclear how the virus affects the animals, according to the study published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Threat level: While human-deer interactions aren't common, deer hunting supports thousands of jobs and generates billions of dollars annually, according to the National Shooting Sports Foundation.

Yes, but: No cases of deer-to-human transmissions have been documented, Tyler Harms, a biometrician with the Iowa Department of Natural Resources, told Axios.

• Basic precautions like wearing gloves and cleaning equipment thoroughly should nonetheless be taken, he said.

Between the lines: The pandemic is still primarily being spread among humans, Suresh Kuchipudi, a scientist from Penn State, told PBS News Hour.

• "We're the initial problem," Vivek Kapur, an infectious disease specialist at Penn State, told PBS. "And we want to make sure that they don't become a problem for us in the future."

The bottom line: Much more research is needed to understand the potential threat, Kuchipudi and Kapur told PBS.