Bats in Laos caves harbor closest relatives to Covid-19 virus

Bats dwelling in limestone caves in northern Laos were found to carry coronaviruses that share a key feature with SARS-CoV-2, moving scientists closer to pinpointing the cause of Covid-19.

Researchers at France’s Pasteur Institute and the University of Laos looked for viruses similar to the one that causes Covid among hundreds of horseshoe bats. They found three with closely matched receptor binding domains -- the part of the coronavirus’s spike protein used to bind to human ACE-2, the enzyme it targets to cause an infection.

The finding, reported in a paper released Friday that’s under consideration for publication by a Nature journal, shows that viruses closely related to SARS-CoV-2 exist in nature, including in several Rhinolophus, or horseshoe bat, species. The research supports the hypothesis that the pandemic began from a spillover of a bat-borne virus. About 1,000 such infections may be occurring daily in southern China and Southeast Asia in areas with dense populations of bats from the Rhinolophus genus, a study Tuesday found.