A study conducted by the United States’ Department of Agriculture (USDA) found that certain white-tailed deer populations in Illinois, New York, Michigan and Pennsylvania were exposed to COVID-19. During the study from January 2020 to 2021 in four US states, 33% of 481 samples tested positive for antibodies to SARS-CoV-2.
An antibody is an immune response to infection, and its presence does not necessarily indicate active infection. In Michigan, 60 percent of the deer samples tested positive for COVID-19 antibodies, followed by Pennsylvania at 34 percent, New York at 18 percent, and Illinois at 7 percent, according to the USDA.
‘We do not know how the deer were exposed to SARS-CoV-2. It’s possible they were exposed through people, the environment, other deer, or another animal species,’ the USDA said on its website. ‘Further research is needed on the significance of SARS-CoV-2 antibodies in free-ranging white-tailed deer, including how the deer were exposed to the virus and potential impacts, if any, to overall deer populations, other wildlife, and people.’
Researchers noted that while the purpose of the study was not to search for clinical signs of illness in deer, no clinical illness was reported in deer that were surveyed. Agriculture’s Animal and Plant Health Inspection Service is working closely with the Department of Interior, the Centers for Disease Control and Prevention (CDC) and the Association of Fish and Wildlife Agencies to determine the next steps.