What are superspreading events?

There has been a lot of talk lately about “superspreading events” and “superspreaders”. What do these terms mean? And what do they have to do with the spread of COVID-19? 

  • Superspreading events don’t have a scientific definition, but you can think of them as anytime one or a few infected individuals get a lot of people sick. One example occurred at a bar in Michigan, which resulted in 170 infections. Superspreader events have occurred in Washington State, South Korea, and elsewhere.
  • Superspreaders, which are also called “supershedders”, are infected individuals who are (for unknown reasons) highly contagious. One study used a mathematical model to estimate that 80% of COVID-19 cases can be linked to only 20% of infected individuals. This study is just one estimate, but suggests that one highly infectious person, who may not even know they are contagious, can cause a lot of infections.

Specifically trying to reduce superspreading events might be important to curbing the pandemic. That means it’s a good idea to avoid places that are at risk for superspreader events. Generally, these events tend to happen in indoor or indoor-outdoor settings with lots of people. So consider steering away from bars, gyms, crowded offices, and parties. 

Japan has made this a cornerstone of their public health approach to the pandemic and advises everyone to  avoid the “Three Cs”: closed spaces with poor ventilation, crowded places, and close-contact settings. So keep yourself and your family safe, and avoid large groups, particularly indoors!


Last update: July 31, 2020, 5:08 pm ET
Science review: JAB, ERS, GSN