Abstract
The basic reproduction number, R0, determines the rate of spread of a communicable disease and therefore gives fundamental information needed to plan public health interventions. Estimated R0 values are only useful, however, if they accurately predict the future potential rate of spread. Using mortality records, we estimated the rate of spread of COVID-19 among 160 counties and county-aggregates in the USA. Among-county variance in R0 estimates was explained by four factors: the timing of the county-level outbreak, population size, population density, and spatial location. The high predictability of R0 makes it possible to extend estimates to all counties in the lower 48 States. The predictability also makes the R0 estimates valuable guides for designing long-term public health policies for controlling COVID-19.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
This work was supported by NASA-AIST-80NSSC20K0282 (A.R.I).
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Footnotes
bozzuto{at}wildlifeanalysis.ch.
Data Availability
Data and code have been uploaded with this manuscript.