The effect of population mobility restrictive measures on the incidence of SARS-CoV-2 infection in the early phase of the pandemic

Background This analysis aims to assess the association between population restrictive measures and the cumulative number of confirmed COVID-19 cases in the early phase of pandemic. Methods We compared mobility data extracted from the Mobility Reports provided by Google with the cumulative number of confirmed cases of COVID-19 of 15 countries provided by John Hopkins University. We compered the number of confirmed COVID-19 cases before and after the peak effect (PE) of population mobility restrictions in each country, defined as the highest percent reduction in mobility measurements. Results Time to PE of population mobility restrictions ranged between 16 and 45 days after the report of the index COVID-19 confirmed case in each country. The most frequent reductions in activities were retail & recreation, parks, and transit & stations, ranging from 30% to 90%. Despite this variability in PE among the countries, the predicted smooth effect after the PE of population mobility restrictions was observed in almost all countries. Conclusions These data suggest that the reduction in mobility was associated with a decrease in the cumulative total number of COVI-19 cases in each country, underscoring that the use of widely available real-time surveillance data might be a valuable resource during this pandemic.