The effect of early-stage public health policies on the transmission of COVID-19 in South American countries

ABSTRACT Objectives The analysis of transmission dynamics is crucial to determine whether mitigation or suppression measures reduce the spread of Coronavirus disease 2019 (COVID-19). This study sought to estimate the basic ( R 0 ) and time-varying ( R t ) reproduction number of COVID-19 and contrast the public health measures for ten South American countries. Methods Data was obtained from the European Centre for Disease Prevention and Control. Country-specific R 0 estimates during the first two weeks of the outbreak and R t estimates after 90 days were estimated. Results Countries used a combination of isolation, physical distancing, quarantine, and community-wide containment measures to staunch the spread of COVID-19 at different points in time. R 0 ranged from 1.52 (95% confidence interval: 1.13-1.99) in Venezuela to 3.83 (3.04-4.75) in Chile, whereas R t after 90 days ranged from 0.71 (95% credible interval: 0.39-1.05) in Uruguay to 1.20 (1.19-1.20) in Brazil. Different R 0 and R t values may be related to the testing capacity of each country. Conclusion R 0 in the early phase of the outbreak varied across the South American countries. The public health measures adopted in the initial period of the pandemic appear to have reduced R t over time in each country, albeit to different levels.