More evidence that covid-19 started in a market, not a laboratory

TWO NEWSARSCV papers provide more robust answers than heretofore available to three of the outstanding questions of the covid-19 pandemic: how, when and where -o-2, the virus that caused it, first appeared in human beings. These papers, so-called preprints (meaning they have not yet gone through the formal process of peer review that precedes publication in a journal) were written by related teams of researchers from institutions around the world and posted to Zenodo, a repository for such documents. They conclude that, by November 2019, the virus was present in animals on sale at the Huanan Seafood Wholesale Market in Wuhan (pictured), whence it jumped to human hosts on two separate occasions a week or so apart.One paper, the lead authors of which are Michael Worobey at the University of Arizona and Kristian Andersen of Scripps Research, in San Diego, attempts to trace the first infections definitively to the Huanan market. The authors used three approaches. First, by looking at the geographic distribution of early infections, they found that the market is in the region where the first covid-19 cases were most densely packed—a result that remains unchanged even when cases with no known link to the market are plotted. Second, they employed photographic evidence posted on Weibo, a Chinese social-media website, as well as contemporary accounts, to show that the market, which vends other goods besides seafood, was selling animals susceptible to the virus (a list that includes porcupines, marmots and raccoon dogs) prior to December 2019.