Tuning in now to hear about retrospective contact tracing. The goal -- interrupting chains of *clusters*!

w/ Hitoshi Oshitani, @kj_seung, @zeynep
https://cyber.harvard.edu/events/retrospective-contact-tracing-how-states-can-investigate-covid-19-clusters

When numbers exceed capacity for tracing, which clusters do public health nurses in Japan prioritize? Vulnerable populations, risky settings.

More resources on the Japanese approach here:
https://responsecovid19.org/tools/ 

How has @PIH and the Massachusetts Contact Tracing Collaborative incorporated retrospective tracing into their approach? @kj_seung explains how they have expanded their protocols beyond the standard WHO/CDC approach.

Clusters are hard to find! Within household transmission is easy to detect (though not easy to prevent). The harder task is connecting cases across households. This requires communication across contact tracers, since tracers are responsible for different households.

Prospective contact tracing focuses on looking forward to see who a case might have infected, but does not always collect data on where the case might have been exposed.

Solution: We need a way to capture the insights of cases and the contact tracers who interview them.

"So what?" Cluster investigations provide actionable intelligence, to local governments, business owners, places of worship, etc. to inform policy decisions about what is and isn't working. These also provide instructive stories to share with the public.