Forget the “R” number, “K” is where it’s at.
When 61 people met for a choir practice in a church in Mount Vernon, Washington, on 10 March, everything seemed normal. For 2.5 hours the chorists sang, snacked on cookies and oranges, and sang some more. But one of them had been suffering for 3 days from what felt like a cold—and turned out to be COVID-19. In the following weeks, 53 choir members got sick, three were hospitalized, and two died, according to a 12 May report by the U.S. Centers for Disease Control and Prevention (CDC) that meticulously reconstructed the tragedy.
Many similar “superspreading events” have occurred in the COVID-19 pandemic.
It seems that the great majority of people who become infected with the Wuhan Virus do not infect other people. For something like 90 percent of infected people, the R number is zero. Most infections happens in clusters, at what has been termed “superspreader” events. Identify those types of events, shut them down early, immediately, and you have already done a lot to prevent the spread. (Guess which country allowed 300,000 people to attend the Cheltenham Festival in mid-March?)
The piece above about such events is in Science Magazine. It’s one of the more interesting pieces I’ve read lately.