New study suggests COVID spread from deer to humans multiple times

A new study has suggested multiple transmission of SARS-CoV-2 from deer to humans based on analysis of samples taken from the animal, reported Xinhua.

The researchers, several of whom work for the U.S. Centers for Disease Control and Prevention or the U.S. Department of Agriculture, collected 8,830 respiratory samples from free-ranging white-tailed deer from 26 U.S. states and Washington, D.C., between November 2021 and April 2022.

They identified 282 deer infected with COVID-19 and 34 different lineages of the virus in the samples collected, including those belonging to the Alpha, Gamma and Delta variants that were more common earlier in the pandemic and the Omicron variant that dominated cases more recently.

Evolutionary analysis showed these white-tailed deer viruses originated from at least 109 independent spillovers from humans, which resulted in 39 cases of subsequent local deer-to-deer transmission and three cases of potential spillover from white-tailed deer back to humans.

The findings suggested that multiple SARS-CoV-2 lineages were introduced, became enzootic, and co-circulated in white-tailed deer, according to the study published in the scientific journal Nature.