Super interesting work on multi-scale approaches to contact tracing. This points to the importance of understanding what communities exist is in each cultural context.
“We analyze the spread of COVID-19 by considering the transmission of the disease among individuals both within and between communities. COVID-19 can be eliminated if the community-to-community reproductive number—i.e. the expected/average number of other communities to which a single infected community will transmit the virus—is reduced to less than one. We find that this community-to-community reproductive number is proportional to the probability that an individual in an infected community will travel to an uninfected community and exponential in the length of the time-delay before community-level action is taken.”