A study by the U.S. Department of Agriculture (USDA) found that white-tailed deer in four states have been exposed to the new coronavirus that causes COVID-19.
The findings, set to be published Tuesday by the Proceedings of the National Academy of Sciences of the United States of America, showed that 40 percent of white-tailed deer—the most common deer in North America—tested across four states in 2021 were positive for SARS-CoV-2 antibodies, meaning they had been exposed to the virus at some point.
Those states were Illinois, Michigan, New York and Pennsylvania. However, previous studies indicated deer in other states have also been exposed to the virus. In all, the research from the studies raises the question on if animal interactions with humans could increase the spread of COVID-19.
Between January and March 2021, the USDA’s Animal and Plant Health Inspection Service tested 481 deer in the four states for the study. Michigan had the highest percentage of positive samples at 67 percent. The lowest percentage (7 percent) of deer with COVID antibodies was recorded in Illinois.
The USDA noted that none of the deer in the study displayed any clinical symptoms of the coronavirus.
The agency also did not come to a conclusion on how the deer became exposed to the virus.
“It’s possible they were exposed through people, the environment, other deer, or another animal species,” the USDA wrote.
Meanwhile, a separate recent study of white-tailed deer in Iowa found that up to 80 percent of those sampled had been infected with the coronavirus. The study, conducted by veterinary microbiologists for Penn State University, said the animals probably contracted the virus from humans before spreading it to one another.
“It was effectively showing up in all parts of the state,” Suresh Kuchipudi, who led the study with Vivek Kapur, told The New York Times in early November. “We were dumbfounded.”
While these studies found antibodies in deer, the USDA had already announced in August that the Ohio State University College of Veterinary Medicine found white-tailed deer in Ohio that had tested positive for the virus. The USDA claimed these were the first deer confirmed with the SARS-CoV-2 virus worldwide.
Scott Weese, a veterinary infectious disease specialist with the Ontario Veterinary College and director of the Centre for Public Health and Zoonoses, told the Global News that most people don’t have to be worried about getting infected by deer.
However, he did say that people who work with farmed deer should be cautious, as should hunters.
“A wounded deer that’s breathing and they’re getting close to it, that could do it,” Weese told the Global News.