In late December 2019, Chinese doctor Li Wenliang contacted members of his medical school alumni group on WeChat. There were seven people in quarantine in his hospital in Wuhan, he wrote; all were from a local seafood market and all were showing signs of a respiratory illness similar to SARS.
Memories of the 2003 outbreak, which infected 8,098 people and claimed 774 lives, were front of the 34-year-old ophthalmologist’s mind.
“I only wanted to remind my university classmates to be careful,” Li later told CNN.