New evidence revealed that SARS-CoV-2 is spreading significantly in white-tailed deer in the U.S., sparking potential concern about long-term implications to the coronavirus pandemic in humans.
In a study published last week, veterinarians at Pennsylvania State University found active SARS-CoV-2 infections in at least 30% of white-tailed deer tested positive across Iowa during 2020. These new findings, which were verified by federal scientists at the National Veterinary Services Laboratories, come on the heels of a USDA study in August that showed 40% of the deer population in the Northeast and Midwest to have antibodies against SARS-CoV-2.
Dr. Diego Diel, an associate professor of virology at Cornell University, explained that SARS-CoV-2 is the “virus that actually causes” the disease COVID-19.
That widespread carriage of SARS-CoV-2 by deer draws concern due to the possibility of the animals carrying the virus indefinitely – to where they could spread it back to humans in periodic form.
Suresh Kuchipudi, a veterinary virologist at Penn State who co-led the study, told NPR: “If the virus has opportunities to find an alternate host besides humans, which we would call a reservoir, that will create a safe haven where the virus can continue to circulate even if the entire human population becomes immune. And so it becomes more and more complicated to manage or even eradicate the virus.
“If we want to continue to be proactive about emerging variants – and not be surprised by one that suddenly pops up – there’s an urgent need to continue to monitor SARS-CoV-2 in wildlife, especially in animals that could serve as a reservoir, like the deer.”
Vivek Kapur, a microbiologist at Penn State and co-leader of the study, said it was “surprising” how many positive cases were found in the lymph nodes of nearly 300 deer, 100 of which were wild, in the study.
“So these deer were either roadkill or free-living deer that hunters had killed (to eat),” he said.
Diel explained that, when an animal population becomes a reservoir, it “complicates control strategies” for the virus, making it “much more difficult to control than when you have a single species involved.”
But he noted that it is “still not known” whether white-tailed deer are “in fact a reservoir of these viruses.” He also said research is not clear on whether these deer can “actually transmit the virus and sustain that transmission in the field,” or whether deer can transmit the virus to humans.
“Those are all very important questions that are still unanswered,” he said.
Iowa Department of Natural Resources spokesperson Tammie Krausman told The Des Moines Register her agency is not recommending specific precautions despite the study’s findings.
Could it happen in other states?:Deer in Iowa appear to be catching COVID-19 from humans.
“DNR recommends that hunters keep hunting, and with standard precautions typically used when processing venison, like wearing gloves and thoroughly cooking the meat, the risk of exposure can be minimized,” she said. “To date, there have been no cases of contracting COVID-19 from eating food, including hunted wild meat.”
Since SARS-CoV-2 first emerged, there has been growing evidence of white-tailed deer being extremely susceptible to the virus. Last September, there was evidence suggesting SARS-CoV-2 could easily bind to enter a deer’s cells. And the USDA study in August revealed that deer in four states had been exposed to the virus.
“At the moment, there’s no immediate cause for concern but justification for precaution. Just as we socially distance from people who could be infected, we also have to think about socially distancing from some animals who could potentially be infected,” Peter Rabinowitz, a physician who specializes in zoonotic diseases and co-directs the University of Washington Alliance for Pandemic Preparedness, told USA TODAY back in August.
The study, which included researchers from Penn State, the Iowa Department of Natural Resources and Iowa State University, featured deer specific to Iowa but stated, “there is no reason to believe that the same thing isn’t happening in other states where deer are present.”
There are an estimated 30 million deer in the U.S. alone, with a majority of the animals native to North America, Central America and the northern edge of South America.