Estimation of Reproduction Number of COVID-19 Spread Patterns in Thailand

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome– coronavirus 2 (SARS-CoV-2) and was declared as a pandemic. The purpose of this study was to estimation the reproduction number of COVID-19 Spread Patterns by using the data from 22 January to 30 June 2020. We applied the exponential growth rate to estimate the basic reproduction number (R₀) according to the status of lockdown. The exponential growth model results during lockdown period indicate the basic reproduction number is 0.58 (95% CI: 0.55-0.60), whereas the basic reproduction number is 0.98 during easing of lockdown. The highest value of the basic reproduction number is 2.48 (95% CI: 2.21-2.77) during pre-lockdown phase II. The reduction of basic reproduction numbers (R₀). suggested that timely implementation of control measures. The estimation of reproduction numbers could be used to analyze and evaluate the effectiveness of control measures and also used as a guide for public health policymakers for future COVID-19 outbreak. Moreover, with COVID-19 cases still present in Thailand, an estimation of basic reproduction number (R₀) would be helpful for continuous monitoring of the effectiveness of the current public health policies implemented in Thailand.