A timeline of COVID-19’s first weeks in Wuhan

CT scans of the couple being treated at Hubei Provincial Hospital show “frosted glass” opacities in their lungs. dr Jixian Zhang, the hospital’s head of respiratory and critical care medicine, insists the couple’s son also get a CT scan, though he has no symptoms of pneumonia. Sure enough, his lungs also have the appearance of frosted glass.

A CT scan of a 65-year-old man in China with COVID-19. Pneumonia caused by the new coronavirus can present as prominent cloudy patches on the outer edges of the lungs, indicated by arrows.

(Mount Sinai Hospital via Associated Press)

A Huanan Market worker with similar CT findings is also admitted to Hubei Provincial Hospital. Zhang reports the four cases to the hospital administrators, and they inform the Jianghan District CDC of a new viral disease. They warn that it is likely contagious.

Vision Medicals informs Wuhan Central Hospital that the 65-year-old delivery man being treated there has been infected with a previously unknown coronavirus. The company produces a nearly complete sequence of the virus genome.