A new study has found extensive COVID-19 infections in Iowaâ€™s white-tailed deer population, prompting concerns about an animal reservoir where the virus could linger, mutate and potentially reinfect humans.
The research, which has not yet been peer-reviewed and was released in preprint Monday, found 12 different strains of SARS-CoV-2, the virus that causes COVID-19, in roughly one-third of 283 deer in the state tested between April and December 2020.
The disease appears to have spread dramatically soon after that initial time period. Additional testing performed from November 2020 through January 2021 found positive results in 82.5% of 97 deer tested.
â€œIt was effectively showing up in all parts of the state,â€ Dr. Suresh Kuchipudi, a veterinary microbiologist at Penn State who co-authored the study, told The New York Times. â€œWe were dumbfounded.â€
Kuchipudi and his colleague Dr. Vivek Kapur said itâ€™s reasonable to assume other states with dense deer populations are seeing similar rates of transmission.
While weâ€™ve known for some time that SARS-CoV-2 can infect a wide range of other species, including dogs, cats, lions, tigers, gorillas and otters, so far, widespread infection of a non-captive animal population like deer hadnâ€™t been documented until now.
â€œOur study is the first to provide evidence of widespread dissemination of SARS-CoV-2 into any free-living species, in this case, white tailed deer,â€ the report reads. â€œOur results suggest that deer have the potential to emerge as a major reservoir host for SARS-CoV-2, a finding that has important implications for the virus genomic diversity and future trajectory of the pandemic.â€
Tyler Harms, a spokesperson for the Iowa Department of Natural Resources, told Des Moinesâ€™ CBS affiliate it appears the deer are getting sick from humans; so far, it hasnâ€™t been the other way around.
With deer hunting season underway, thatâ€™s a critically important distinction. Harms said the state is recommending hunters wear masks and gloves if they are in close physical contact with deer, and that meat be cooked to an appropriate temperature before itâ€™s consumed.
Scientists have long worried COVID-19 could find an animal reservoir from which variants of the disease could reemerge and infect humans at some point in the future.
Given the estimated 30 million white-tailed deer distributed throughout the continental U.S., and their penchant for living in close proximity to humans, the authors conclude thatâ€™s a very real concern and merits closer surveillance.