https://www.wired.com/story/how-promed-crowdsourced-the-arrival-of-covid-19-and-sars/

It was about 8:30 pm on December 30, and Marjorie Pollack, a physician and epidemiologist, was working in her home office in Cobble Hill, Brooklyn.

Her email pinged. In her inbox was a note from a frequent and reliable contributor to ProMED, an email list of disease alerts for which Pollack serves as deputy editor. The contributor, who speaks and reads Chinese, wanted her to know about a new post that was getting some attention on Weibo, a within-China social media network. The post said that a few hours earlier, the Wuhan Municipal Health Committee had issued “an urgent notice on the treatment of pneumonia of unknown cause.”