November 17, 2021 — A new study has found high rates of SARS CoV-2 (the virus that causes COVID-19) exposure and active infection among white-tailed deer tested across Iowa. Previously, antibodies detected in deer suggested exposure to the virus, but this is the first confirmation of active infection and deer-to-deer transmission.
Researchers at Penn State University also used genome sequencing of the viral samples to learn that SARS CoV-2 reached deer through multiple “spillover” events from humans. There is still no evidence that deer can transmit the disease to humans in a “spillback” direction.
The new study in Iowa deer, added to previous revelations of exposure in other states, suggests SARS CoV-2 is much more widespread in whitetails than previously thought and that deer are extremely susceptible to infection with the virus. Although deer become infected, there have not been reported clinical signs, and there is no evidence yet that the infection is a serious health threat to deer.
We don’t know how these deer became exposed to the virus. Humans are the virus reservoir, so possibilities include direct contact between deer and humans such as with captive or human-habituated deer, indirect contact such as through contaminated feed or bait, and other routes, but more study is needed.
In the new study, Penn State researchers sampled lymph nodes from 151 free-ranging and 132 captive deer across Iowa from April 2020 through January 2021. Overall, 33% of deer had been infected. However, the infection grew higher toward the end of the testing period. During the last few weeks from November 23, 2020 to January 10, 2021, 82% of 97 deer were infected.
Currently, there is no confirmed risk to you of COVID-19 infection from handling deer, field-dressing deer, or eating cooked venison. However, as recommended by the Centers for Disease Control, it is a good idea to protect your health by wearing disposable latex gloves whenever you are processing a deer. Then wash your hands, knife and other equipment thoroughly when done.
More study of the SARS-CoV-2 virus in deer is needed. If your state wildlife agency asks you to assist by submitting samples from harvested deer, NDA encourages you to participate in such volunteer opportunities if possible. Your help will enable research that ultimately protects our priceless deer resource.
Meanwhile, if you encounter an obviously sick deer, report it immediately to your state wildlife agency. Assisting with awareness and monitoring is one of the best ways hunters can help fight all deer diseases.