Michael Worobey, an evolutionary biologist at the University of Arizona, has pieced together clues from earliest days of the outbreak. Writing in the journal Science, he strengthens the case that the Huanan Market was the most likely source of the SARS-CoV-2 virus.
Here’s a closer look at some of the key events.
Nov. 18, 2019 — The novel coronavirus that is later named SARS-CoV-2 infects a human for the first time. (This date is an estimate.) Whoever this patient is, he or she was probably not admitted to a hospital — and may not have experienced any symptoms of what became known as COVID-19.
Dec. 13, 2019 — A 65-year-old deliveryman at the Huanan Market reports symptoms of COVID-19, though the records are unclear and this may have occurred two days later.
…
Dec. 18, 2019 — Dr. Fen Ai, director of the emergency department at the Central Hospital of Wuhan, treats the 65-year-old deliveryman for unexplained pneumonia. A CT scan shows an infection in both lungs, which did not clear up despite treatment with antibiotics and anti-influenza drugs.
…
Dec. 26, 2019 — The analysis of the deliveryman’s lung sample reveals he is infected with a new coronavirus related to the one that causes Severe Acute Respiratory Syndrome, or SARS.
