One Reason Why We Could Crush the Curve: A Recent Ohio Outbreak

If we were to tighten restrictions for about two months, tops. Recently, the Ohio Department of Public Health released a figure describing an outbreak that was started by one infected person who went to church (I haven’t seen any information about distancing or mask wearing during the services). Here’s how the outbreak spread:

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Several things about this outbreak suggest why it wouldn’t be that hard to massively lower prevalence:

  1. The superspreading was limited in space and time. Despite the initial case’s ability to spread it to dozens of other people, almost all of those happened in this one church and during one service (he did infect several family members). He didn’t infect co-workers or other groups. This is similar to the ‘bus spreading’ case in China–the index case there didn’t infect anyone else. This suggests it takes the right (or wrong?) set of circumstances to spread the virus–and we have pretty good ideas about what those circumstances are.
  2. Most of the spread after the initial case occurred in households. Only five out of the 91 subsequent cases involved spread to co-workers. If we know someone has COVID-19, this will allow us to target resources effectively. We also can quarantine preemptively close relatives until test results are returned, which will help. Again, this isn’t anything new–family spread is one reason China set up quarantine and isolation centers away from people’s families. I’m not suggesting that should be mandatory, but governments should provide that as an option, if desired.
  3. The number of tertiary cases was small, and were derived from three of out of 54 secondary cases (five out of 91 people; hopefully, I did all the countings right!). Most people who subsequently were infected didn’t then pass it to other people (there might have been some within-family transmission). This is not explosive, ‘exponential’* (or exponential) growth that is impossible to stop. If we had an ‘isolation-from-family’ policy (again, not saying this should be mandatory), there might have been as few as one secondary case.

This is not the Andromeda Strain. If we were to set up the necessary economic boundary conditions, followed by good public health policy, we could lower prevalence to the point where COVID-19 would be very rare.

*‘Exponential’ is has, in colloquial terms, simply come to mean “lots.”

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