Predicting Growth of COVID-19 Confirmed Cases in Each U.S. County with a Population of 50,000 or More

Robertson, Leon S

A simple model of local spread of COVID-19 is needed to assist local governments and health care providers prepare for surges of clinical cases in their communities. National and state based models are inadequate because the virus is introduced and spreads at different rates in local areas. In the U.S. as of July 3, 2020, 73 percent of cases and 84 percent of deaths occurred in the 200 counties with the most cases and deaths. Each county has its own function of cases in time that can be used to predict increases in reported cases two weeks in advance for each of 988 counties in the U.S. with populations of 50,000 or more inhabitants. A logarithmic model based on growth in cases during the past 30 days is substantially predictive of increase in cases during the subsequent 14 days. Predicted increase in cases for the 988 U.S. counties will be published online daily.