Related Articles Transmission potential and severity of COVID 19 in South Korea Int J Infect Dis 2020 Mar 17 Authors Shim E Tariq A Choi W Lee Y Chowell G Abstract OBJECTIVES Since the first case of 2019 novel coronavirus COVID 19 identified on Jan 20 2020 in South Korea the number of cases rapidly increased resulting in 6 284 cases including 42 deaths as of March 6 2020 To examine the growth rate of the outbreak we aimed to present the first study to report the reproduction number of COVID 19 in South Korea METHODS The daily confirmed cases of COVID 19 in South Korea were extracted from publicly available sources By using the empirical reporting delay distribution and simulating the generalized growth model we estimated the effective reproduction number based on the discretized probability distribution of the generation interval RESULTS We identified four major clusters and estimated the reproduction number at 1 5 95 CI 1 4 1 6 In addition the intrinsic growth rate was estimated at 0 6 95 CI 0 6 0 7 and the scaling of growth parameter was estimated at 0 8 95 CI 0 7 0 8 indicating sub exponential growth dynamics of COVID 19 The crude case fatality rate is higher among males 1 1 compared to females 0 4 and increases with older age CONCLUSIONS Our results indicate early sustained transmission of COVID 19 in South Korea and support the implementation of social distancing measures to rapidly control the outbreak PMID 32198088 PubMed as supplied by publisher