COVID-19 infected deer could act as ‘reservoirs’ for virus, study suggests

A new study has looked into how COVID-19 cases are spreading among the white-tailed deer population — leaving some scientists to wonder if the virus could jump back to humans.

A group of veterinarians at Penn State published the study, although it has yet to be peer-reviewed.

"Many animal species are susceptible to SARS-CoV-2 and could potentially act as reservoirs, yet transmission in non-human free-living animals has not been documented," the study’s authors noted. 

RELATED: 3 snow leopards die from COVID-19 complications at Nebraska zoo

Researchers looked into deer-to-deer coronavirus transmission. They examined the lymph nodes of 151 free-living and 132 captive deer in Iowa from April 2020 through December 2020 for the presence of the novel coronavirus. Researchers found that more than 30% of the deer had tested positive for the coronavirus. 

During the winter surge, researchers found about 80% of the studied deer tested positive for the coronavirus. Researchers believe that the studied deer contracted the virus from humans and spread it to other deer. 

"Based on the genomic information, we were able to demonstrate that the source of the virus to the deer was indeed human beings," lead researcher Dr. Suresh Kuchipudi told FOX Television Stations Monday.

Researchers questioned whether humans can contract the virus from deer, and what that could mean for the fight to end the pandemic.

Kuchipudi said it’s possible, but more research needs to be done. Kuchipudi said other viruses can pass from wild animals to human beings.

"Since SARS-CoV-2 infects animals as well as humans, it is plausible that an infected animal could indeed infect human beings," he added. 

RELATED: Maryland Zoo in Baltimore to begin vaccinating some animals against COVID-19

Researchers are also concerned that infected deer could develop new variants of the coronavirus that could spread to humans. They’re urging health officials to reshape the way they approach research into ending the pandemic. 

"These findings highlight an urgent need for a robust and proactive "One Health" approach to obtaining a better understanding of the ecology and evolution of SARS-CoV-2," researchers continued.

Kuchipudi said the "One Health" means U.S. health officials should approach and tackle human and animal health concerns simultaneously, including monitoring and studying cases in both species. He said the COVID-19 vaccine is one example as people and zoo animals get inoculated. 

Infections have been reported in multiple species worldwide, mostly in animals that had close contact with a person with COVID-19, according to the United States Department of Agriculture.

In early November, three snow leopards died at the Lincoln Children’s Zoo in Nebraska of complications from COVID-19.

Zoos across the country, including at the St. Louis Zoo and the Denver Zoo, have battled COVID-19 outbreaks among their animals.

Two hyenas at the Denver Zoo have tested positive for the coronavirus earlier this month as well, the first confirmed cases among the animals worldwide. In addition to the two hyenas, 11 lions and two tigers at the zoo tested positive for the virus.

The Associated Press contributed to this report. This story was reported from Los Angeles.