Preliminary estimating the reproduction number of the coronavirus disease (COVID-19) outbreak in Republic of Korea and Italy by 5 March 2020

Zhuang, Zian; Zhao, Shi; Lin, Qianying; Cao, Peihua; Lou, Yijun; Yang, Lin; Yang, Shu; He, Daihai; Xiao, Li

The novel coronavirus disease 2019 (COVID-19) outbreak and Italy has caused 6088 cases and 41 deaths in Republic of Korea and 3144 cases and 107 death in Italy by 5 March 2020. We modeled the transmission process in Republic of Korea and Italy with a stochastic model and estimated the basic reproduction number R0 as 2.6 (95% CI: 2.3-2.9) or 3.2 (95% CI: 2.9-3.5) in Republic of Korea, under the assumption that the exponential growth starting on 31 January or 5 February 2020, and 2.6 (95% CI: 2.3-2.9) or 3.3 (95% CI: 3.0-3.6) in Italy, under the assumption that the exponential growth starting on 5 February or 10 February 2020. Estimates of dispersion term (k) were 10 (95% CI: 5-56) or 22 (95% CI: 8-61) in Republic of Korea, and 13 (95% CI: 5-61) or 37 (95% CI: 13-61) in Italy, and all of which imply few super-spreading events.