Scientists have determined that the coronavirus type SARS-CoV-2, which is the cause of COVID-19, can spread very quickly among white-tailed deer in some parts of the USA. While it’s still unclear whether the virus can bounce back from deer to humans, the findings may have some worrying implications for the course of the epidemic.
In a new study, scientists tested SARS-CoV-2 on a total of 283 white-tailed deer, including 151 free-living and 132 captured, in Iowa from April 2020 to December 2020. 33 percent of the animals were found to be infected with the virus. Of the 97 samples taken privately between November 23, 2020 and January 10, 2021, a shocking 82.5 percent were positive.
The research, which has yet to be peer-approved, was published earlier this month on prepress server bioRxiv.
The high numbers and distribution of cases indicate that the virus has been transmitted multiple times from humans to deer and then productively spread through deer-to-deer transmission. Fortunately for deer, infections appear to be asymptomatic and there is no evidence that animals are badly affected by the virus.
Similar findings were obtained in previous studies. In August, scientists published a study showing that 40 percent of wild deer living in Illinois, New York, Michigan, and Pennsylvania tested positive for antibodies to SARS-CoV-2.
Although human-to-deer transmission and deer-to-deer transmission can easily be predicted, none of the studies have found whether deer-to-human transmission is possible. But if the virus is able to jump from deer to humans, that could have quite alarming consequences. First, it raises the possibility that the deer would act as a natural reservoir for the virus, quietly harboring the infection, and leading to new human COVID-19 outbreaks in the future. The second, and perhaps most worrisome, danger is the increased likelihood of fostering the emergence of new variants.
“In principle, SARS-CoV-2 infection of a non-human animal host may cause it to become a reservoir leading to the emergence of new variants that are at risk of spreading to humans,” the article states.
While based on data, this is all guesswork for now and more research is needed, but the risk to humans is considered low. “At this time, there is no evidence that animals play a significant role in the spread of SARS-CoV-2, the virus that causes COVID-19, to humans,” the U.S. Department of Agriculture said in August. The risk of infecting humans seems low.”
Of course, deer aren’t the only virus hosts of concern. Researchers believe it is possible for many mammalian species to contract the disease. So far, evidence of SARS-CoV-2 has been documented in cats, dogs, tigers, mink and many more species.
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