One of 18 scientists to sign a May letter upping the idea that the novel coronavirus may have leaked from the Wuhan Institute of Virology says new evidence points in another direction: the Huanan Seafood Wholesale Market. "I do think transmission from another species, without a lab escape, is the most likely scenario by a long shot," Michael Worobey, an evolutionary biologist at the University of Arizona, tells NPR. "The data are very consistent with it starting at the market." A March report from the World Health Organization was inconclusive on whether the outbreak started at the market, though it did suggest transmission from bats to humans through another animal. Worobey—co-author of a new online review who's used computer models to show how SARS-CoV-2 spread through Wuhan, China—says that report failed to look at the location of early known COVID-19 cases in relation to the market.
Since signing the letter, Worobey has worked with microbiologist Robert Garry of Tulane University to map where people with early confirmed cases lived in Wuhan. The Wuhan Institute of Virology sits outside the initial cluster of cases. But the seafood market, more than 10 miles away, "seems like the bull's-eye," says Worobey. "It's pretty extraordinary." Plus, a recent study showed the market was one of four in Wuhan selling illegal wildlife, including palm civets and raccoon dogs, "which are the likely suspects as intermediaries to SARS-CoV-2," says Worobey. Civets are thought to have caused the SARS-CoV pandemic in 2003, per NPR. This new research comes as WHO director-general Tedros Adhanom Ghebreyesus calls on China to release early "raw data" and allow greater access to its labs so scientists can better understand SARS-CoV-2's origin, per Science. (Wuhan's only foreign virologist thinks the lab-leak theory is unlikely.)