Some wild white-tailed deer populations in the US have been exposed to COVID-19. The USDA recently released the results of a year-long study.
For more than a year, the USDA’s Animal and Plant Health Inspection Service (APHIS) has been analyzing blood samples from free-ranging white-tailed deer in four states.
Researchers were looking for SARS-COV-2 antibodies.
And they found them.
Deer from Illinois, Michigan, New York, and Pennsylvania were tested. Of the 481 total samples taken between January 2020 and March 2021, 33% came back with a positive antibody test.
The results varied by State (Illinois = 7 percent of 101 samples contained antibodies; Michigan = 67 percent of 113 samples; New York = 19 percent of 68 samples; and Pennsylvania = 31 percent of 199 samples).
Researchers also tested old blood samples from before COVID-19 was first detected in humans in the U.S. Only one test came back positive. Researchers attribute that to a false positive.
“It’s important to study the susceptibility of certain mammals like white-tailed deer to SARS-CoV-2 to help us identify if other animals can serve as hosts or reservoirs for the virus as well as understand the origin of the virus and predicts its impact on the wildlife populations and the risks of cross-species transmission,” Dr. Thomas DeLiberto, Assistant Director of the National Wildlife Research Center for the USDA’s APHIS.
The study was limited and was only looking at whether wild deer has been exposed. It found out yes, they have been or at least these ones have.
DeLiberto said because of that they’re left with a lot of questions.
Researchers don’t know how the deer were exposed. It could be from humans or environmental factors. DeLiberto said it’s likely multiple types of exposure, not a single source.
They also don’t know if the virus is circulating among deer or how the virus could impact deer populations.
From what’s been observed in the field and in controlled settings, white-tailed deer exposed to COVID have not shown signs of illness.
DeLiberto also stressed that just because roughly a third of the samples that came back had COVID antibodies, it does not mean a third of deer populations in the US have been exposed to the virus.
“This study, again, was really only designed to see if deer were being exposed or not. It’s very difficult, and really impossible, to make any inference about the level of the percent that we detected,” he said. “We definitely shouldn’t be comparing the percentages across states.”
Researchers say the risk that the deer could spread the virus to people is low, and there’s never been any evidence you can get covid from preparing or eating meat from an animal that’s infected.
DeLiberto said the USDA will be working with other federal and state agencies to answer the questions the results of this study have created.
