This story is corrected to show that 245,000 cases are linked to the mutation, and that another 88,000 cases are a subset of those 245,000 cases(CNN) A biotech conference in Boston last February that's already been flagged as a Covid-19 superspreading event led to at least 245,000 other cases across the US and Europe, a new genetic fingerprinting study shows. One single case seems to have been responsible for many of the other eventual cases, the team at the Broad Institute in Massachusetts reported. Their study finds two particular genetic fingerprints of viruses associated with the conference and then tracks those lineages across the US. A virus carrying one mutation -- a small genetic change they've flagged as C2416T -- was apparently carried to the conference by a single person, and ended up infecting 245,000 people. A subset of the viral strain with a mutation known as G26233T ended up in 88,000 of these cases.

Source: CNN December 11, 2020 18:56 UTC