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

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 (R₀) 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 R₀ values during the first two weeks of the outbreak and R_t values 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. R₀ 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 R₀ and R_t values may be related to the testing capacity of each country. Conclusion. R₀ 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.