In March, 43.5% of workers on a South Korean call center floor were infected with #COVID19. Look how the cases cluster in a packed indoor space, and spare others not in the same space.

This is the Broad Street pump map for the 21st century
https://wwwnc.cdc.gov/eid/article/26/8/20-1274_article (via @zeynep)

This is the 11th floor. Notice that everyone uses the same elevator bank, but infections cluster anyway.

96% of infections in the building were on this floor.

This suggests certain inferences about the danger of transmission on shared surfaces and in elevators.

The main accelerant appears to be sitting in a closed space, huffing other people’s air for an extended period.

Now I’m wondering about South Korean elevator etiquette. What were these colleagues in a call center bullpen doing that they wouldn’t also do in an elevator?

Also noteworthy: only 4.1% of the #COVID19 cases were totally asymptomatic. (Some were asymptomatic at the time of testing but later developed symptoms.)

Let me also call attention to this awesome power of South Korean contact tracing, which is something Americans can’t even opt in to if they want it:

My phone already tracks me everywhere I go. Yours probably does too. But for some reason it lacks the trivially simple functionality of letting me share that information and increase my ability to know whether I have been exposed to a deadly disease