OBJECTIVES: On March 15, 2020, 61.3% of the confirmed cases of COVID-19 infection are associated with the worship service that was organized on February 9 in the Shincheonji Church of Jesus in Daegu, South Korea. In this study, we aim to evaluate the effects of mass infection in South Korea and assess the preventive control intervention. METHOD: Using opened data of daily cumulative confirmed cases and deaths, the basic and effective reproduction numbers was estimated using a modified susceptible–exposed–infected–recovered-type epidemic model. RESULTS: The basic reproduction number was estimated to be [Formula: see text]. The effective reproduction number increased approximately 20 times after the mass infections from the 31 st patient, which was confirmed on February 9 in the Shincheonji Church of Jesus, Daegu. However, the effective reproduction number decreased to less than unity after February 28 owing to the implementation of high-level preventive control interventions in South Korea, coupled with voluntary prevention actions by citizens. CONCLUSION: Preventive action and control intervention were fairly established in South Korea.
Evaluation of COVID-19 epidemic outbreak caused by temporal contact-increase in South Korea