COVID-19 antibodies found in white-tailed deer

MADISON, Wis. — The U.S. Department of Agriculture’s Animal and Plant Health Inspection Services recently found SARS-CoV-2 antibodies in certain populations of free-ranging white-tailed deer in a recent study.

The study analyzed samples of deer in Illinois, Michigan, New York and Pennsylvania.

Thomas DeLiberto, who is the assistant director of the USDA’s APHIS National Wildlife Research Center, said “The fact that we saw antibodies in deer in all four states would suggest to us that the exposure is probably happening on a much broader geographic scale,” including in Wisconsin.

DeLiberto said APHIS decided to do this study because previous research showed that white-tailed deer are susceptible to infection in experimental situations and could transmit it to other deer populations. He added that there are roughly 30 million deer in the US, many of which come into close contact with humans.

APHIS collected 481 samples between January 2020 and March 2021 from the four states. They compared it to two sets of frozen blood samples of white-tailed deer from 2011.

“We only looked at the deer in four states because those are the only states that we had access to samples to during the pandemic,” DeLiberto said. “We found no antibodies in the pre-pandemic samples. But when we looked at the pandemic samples, we noticed there was a sharp spike in antibodies to the SARS-CoV-2 virus.”

The study detected the antibodies in 33% of the sample size tested. In Illinois, 7% of the 101 samples contained antibodies. In Michigan, 67% of the 113 samples contained antibodies. New York’s 68 samples showed 19% with antibodies present. In Pennsylvania, 199 samples were collected with 31% showing antibodies.

DeLiberto said this sample size should not be used to draw conclusions about deer populations as a whole in any of the states.

“Our study was a really introductory survey that just looked at relatively small sample sizes in very focal areas,” he said. “We would have to do a much more in-depth study to determine that. We are currently working on communicating with our state departments of natural resources to develop plans and understand how many deer in each state have been exposed to the virus.”

DeLiberto said studying the samples gives the USDA a better idea about which species of animals that can serve as hosts to the virus, helps predict the impact on wildlife and the risks of cross-species transmission.

He added that Wisconsin’s popular deer hunting season should pose no concern to hunters as long as they follow standard safety precautions.

“To date there is no evidence whatsoever that people can get COVID-19 from eating food of any type,” DeLiberto said.  “Wear gloves if you can, wear eye protection, try to disinfect your tools after you’re done preparing and dressing your meat and cook your meat thoroughly. Simple precautions that we’ve always recommended hunters take to protect them from getting any disease. Those recommendations have not changed with this study,” DeLiberto said.

The study also did not find any indication that the deer had any signs of being sick from COVID-19 or had been infected.

“What surprised us more than we were seeing it in all four states over such a large geographic area,” DeLiberto said.

For more information on the study, click here.