Americans have transmitted COVID-19 to wild deer hundreds of times, an analysis of thousands of samples collected from the animals suggests, and people have caught and spread mutant variants from deer at least three times.
Analysis Published on Monday It stems from the first year of a multi-year federal effort by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, or APHIS, to study the virus’ spread in U.S. wildlife.
From November 2021 to April 2022, scientists analyzed 8,830 samples collected from wild white-tailed deer in 26 states and Washington, D.C., testing for the type of covid that infected 282 of them.
By comparing sequences of viruses in deer with other publicly reported samples Databases of human infections They were able to trace the spread of these variations between humans and animals around the world.
A total of 109 “independent spillover events” were identified, with viruses found in deer matching precursors from previously infected humans.
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Many of these viruses appear to still be changing and spreading among deer, including alpha, gamma, and delta types, leading to an increase in deaths earlier in the epidemic, even after these lineages have been buried by successive waves of omicron types. Dominate the entire country.
Eighteen samples were reported to have “no genetically close human SARS-CoV-2 sequences at the same position,” which hampered efforts to detect precursor variation in humans.
“Overall, this study demonstrated that new human viruses continue to be frequently introduced into free-ranging white-tailed deer, and that SARS-CoV-2 VOCs are capable of persisting in white-tailed deer even after those variants have become rare in the human population,” the study’s authors wrote.
All three had mutations that matched a unique pattern of transmission first from a human to deer, and then from deer back into humans in another so-called “spillback.” Two of these spillback types were in North Carolina and one in Massachusetts.
An investigation with the Centers for Disease Control and Prevention found three individuals infected with a variant of this hallmark deer mutation, as well as a handful of zoo lions infected with the same strain.
None of the humans claimed to have a close relationship with the deer or the zoo.
Zoonotic diseases
APHIS researchers is studying Can white-tailed deer, among many American wildlife species, act as so-called “reservoir species” over long periods of time when the virus mutates? spread among deer.
Previous report from Scientists in Canada A “highly divergent lineage of SARS-CoV-2” transmitted from deer to humans was detected.
As the virus spreads between humans and wildlife, government scientists are concerned about how it might affect animals.
“Deer routinely interact with humans and are commonly found in human environments — near our homes, pets, wastewater and garbage,” University of Missouri professor Xiu-Feng Wan said in a news release. liberation Announcing the results.
The paper’s authors pointed to other examples of diseases spreading between people and deer, like the previous outbreak of bovine tuberculosis among deer. That was attached For local “supplementation” efforts to boost wild deer populations in Michigan.
The CDC previously urged Americans to avoid close contact with wildlife and their waste, both of which reduce transmission. of SARS-CoV-2 As well as other so-called dangerous Zoonotic diseases Spread between humans and animals.
“The potential for SARS-CoV-2, or any zoonotic disease, to persist and evolve in wildlife populations may pose unique public health risks,” Wan said.
