A third of Northeast Ohio deer tested positive for COVID-19 earlier this year, study shows

Researchers at The Ohio State University say they have confirmed COVID-19 infections in wild white-tailed deer in six locations in Northeast Ohio.

Scientists took nasal swabs from 360 deer culled as part of a population control initiative, according to the results of the study that appeared in the journal Nature earlier this month. The samples, taken between January and March before the delta variant became dominant in the U.S., came from deer that had been living in close proximity to humans. More than a third tested positive for COVID-19.

The confirmation of infections means scientists will need to watch the virus in the deer population to see if it poses a threat to humans – the same way flu infections in birds and pigs are monitored, said the senior author of the paper, Andrew Bowman, associate professor of veterinary preventive medicine at Ohio State University.

The risk is that the virus could mutate while infecting the deer population, creating new variants that could jump back into humans or be passed on to other animal species, he said.

“Currently, we’re doing surveillance looking at humans. We’d have to do surveillance looking at animals as well and assess if the viruses that are in animals pose a different threat than what we have in humans and if they were going to spill back in how would we control that,” Bowman said.

The deer showed no symptoms of infection, but Bowman’s study found that humans infected deer with the virus six separate times.

How that happened is anybody’s guess, he said.

Deer could have been infected by drinking contaminated water, rummaging through human trash, or even by hand feeding, Bowman said.

“However it’s happening, it seems to be fairly easy,” he said.

While the study confirmed deer can be infected with the virus, there are still many unknowns. Scientists do not know how the virus behaves in the deer’s body, how far one infection can spread through the deer population, how long infections last, or whether deer can infect humans.

“Those that are coming in contact with deer have to consider the idea that they may have SARS-COVID-2 much like you would a person. And so I think you have to consider the same precautions that fit your risk tolerance,” he said. “If you’re at high risk or concerned of that transmission, I think using precautions such as face mask, gloves, face shield would be certainly warranted.”

In August, the U.S. Department of Agriculture released a fact sheet on COVID-19 exposure in deer. At that point there was no evidence people could get COVID-19 by preparing or eating meat from infected animals. But, they warned, hunters can be infected with many other diseased when processing or eating game and urged hunters to practice good hygiene and to follow food safety recommendations.

The Ohio Department of Natural Resources is also asking people to avoid luring a concentration of deer including at backyard feeders or in hunting situations. 

In addition to COVID-19, ODNR said that chronic wasting disease and bovine tuberculosis can be easily transmitted from deer to deer.

The deceased deer tested by OSU were part of a population control initiative and are therefore not a transmission threat.