Thousands of samples have been analyzed, and it appears that Americans have introduced COVID-19 to wild deer hundreds, if not thousands, of times.
According to other evidence, humans have caught and disseminated a mutant deer at least three times. The United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) has financed multiyear research to explore the virus’s spread among American animals, and these data are from the first year of that study.
As per CBS News, between November 2021 and April 2022, investigators in 26 states and the District of Columbia gathered and analyzed a total of 8,830 samples from wild white-tailed deer. COVID-19 mutations were found in 282 of the deer. Researchers compared viral sequences from deer to publicly accessible data from human illnesses throughout the world to determine how these variations likely spread from humans to animals.
During the study, 109 “independent spillover events” were discovered that linked viruses in deer to previously exposed individuals. At least three of these viruses—the Alpha, Gamma, and Delta strains—are still mutating and spreading in wild deer populations. Even while Omicron variants are presently the most frequent in the United States, other variations continue to raise concern.
There were no closely related human SARS-CoV-2 sequences in the same condition, making determining the origin of 18 of the samples difficult. These three samples contain peculiar mutation patterns, indicating a chain reaction that began with human-to-deer transmission and ended with “spillback” to humans.
Massachusetts experienced one of these spillover varieties, whereas North Carolina had two. The CDC conducted more research and discovered that three humans had infected the strain with the deer mutation. Despite the fact that no human instances of this strain have been reported in close vicinity to deer or the zoo, numerous zoo lions have become ill as a result of it.
According to this study, white-tailed deer and other wild animals in the United States will continue to function as viral reservoirs for the foreseeable future. Scientists are looking at whether these animals might serve as a reservoir for the virus, allowing it to evolve and spread among deer. SARS-CoV-2 had significant alterations throughout its passage from deer to people, according to Canadian scientists.
Deer are frequently found in close proximity to homes, pets, sewage, and rubbish because of their frequent encounters with humans, all of which enhance the potential of disease transmission. Previous outbreaks of illnesses such as bovine tuberculosis in deer in Michigan have been connected to local efforts to increase wild deer populations through supplemental feeding.
In light of these results, the CDC has advised the general people to avoid contact with wildlife and their droppings in order to reduce the spread of SARS-CoV-2 and other zoonotic infections. The authors of the study emphasized that allowing zoonotic illnesses to thrive and evolve in wild animal populations puts human health at risk.