Spatiotemporal pattern of COVID-19 and government response in South Korea (as of May 31, 2020)

Kim, Sun; Castro, Marcia C.

Abstract Objectives The aim of this study is to assess how COVID-19 clustered across districts in South Korea and to assess whether the pattern and duration of clusters changed following the country’s containment strategy. Methods We conducted spatiotemporal analysis of COVID-19 daily confirmed cases by 250 districts in South Korea from January 20 to May 31, 2020, obtained from the Korea Centers for Disease Control and Prevention and each provincial website. Global Moran’s I statistic was used for spatial autocorrelation analysis and retrospective space-time scan statistic was used to analyze spatiotemporal clusters of COVID-19. Results The geographical distribution showed strong spatial autocorrelation, with a global Moran’s I coefficient of 0.784 (p = 0.0001). Twelve statistically significant spatiotemporal clusters were identified by space-time scan statistic using a discrete Poisson model. The spatial pattern of clusters changed and the duration of clusters became shorter over time. Conclusions Results indicate that South Korea’s containment strategy of COVID-19 was highly effective in both early detection and mitigation, with recent clusters being small in size and duration. Lessons from South Korea should spark a discussion on epidemic response.