White-tailed deer, a species found in every U.S. state except Alaska, appear to be contracting the coronavirus in the wild, according to the first study to search for evidence of an outbreak in wild deer.
Researchers with the U.S. Department of Agriculture (USDA) analyzed blood samples from more than 600 deer in Michigan, Illinois, New York, and Pennsylvania over the past decade, and they discovered that 152 wild deer, 40 percent of the deer tested from January through March 2021, had antibodies to SARS-CoV-2, the virus that causes COVID-19. Another three deer from January 2020 also had antibodies.
Their presence means that deer likely had encountered the virus and then fought it off. The animals didn’t appear sick, so they probably had asymptomatic infections, the agency says. Roughly 30 million white-tailed deer live in the U.S.
“The risk of animals spreading SARS-CoV-2 to people is considered low,” the USDA told National Geographic in a statement. Still, the results may suggest that “a secondary reservoir for SARS-CoV-2 has been established in wildlife in the U.S.” says Jüergen Richt, a veterinarian and director of the Center on Emerging and Zoonotic Infectious Diseases at Kansas State University who was not involved in the USDA’s work. If the virus is circulating in other species, it could continue to evolve, perhaps in ways that make it more severe or transmissible, undermining efforts to slow the pandemic.
Earlier this year, researchers established that deer are susceptible to the virus when infected in the lab—and that they...