More than a third of white-tailed deer in the northern US carry antibodies to SARS-CoV-2, raising questions about how they may have been exposed, Nature News reports.
Researchers from the National Wildlife Research Center, part of the US Department of Agriculture's Animal and Plant Health Inspection Service, analyzed 624 serum samples that were collected from white-tailed deer, Odocoileus virginianus, both before and after the start of the COVID-19 pandemic, as they report in a preprint posted to BioRxiv. Nature News notes that previous lab-based studies had found that O. virginianus can become infected with SARS-CoV-2 and pass it to other deer.
In their new, yet-to-be peer reviewed study, NWRC's Susan Shriner and her colleagues found that SARS-CoV-2 antibodies were present in 40 percent of the deer samples collected in 2021. That seroprevalence varied by state, with the highest, 67 percent, in Michigan and the lowest, 7 percent, in Illinois. Three deer samples from 2020 also harbored antibodies.
National Geographic notes that the agency says the deer do not appear ill and suggests that they had asymptomatic infections and Nature News adds, as the researchers did not conduct viral RNA testing, they cannot say whether deer are a viral reservoir.
Nature News further reports that how the deer may have been exposed to the virus is something of a mystery, but could be due to contact with people, other animals, or with affected wastewater.