Transmission potential of the novel coronavirus (COVID-19) onboard the diamond Princess Cruises Ship, 2020

Mizumoto, Kenji; Chowell, Gerardo

This is the first study to assess the transmission potential of the COVID-19 outbreak that unfolded aboard the Diamond Princess Ship, JanuaryeFebruary 2020. The overall mean reproduction number in the confined setting reached values as high Black dots shows observed data, and light and dark indicates 95% and 50% credible intervals for posterior estimates, respectively. Day 1 on horizontal axis corresponds to January 20, 2020. as~11, which is higher than mean estimates reported from community-level transmission dynamics in China and Singapore in the range 1.1e7 (Li et al., 2020a; Li et al., 2020b; Mizumoto, Kagaya, & Chowell, 2020a; Read, Bridgen, Cummings, Ho, & Jewell, 2019; Sanche et al., 2020; TariqALee et al., 2020; Wu, Leung, & Leung, 2020) . However, following the implementation of the quarantine period, the overall R t decreased substantially compared to values estimated during the early stage, but it exhibited fluctuations around the epidemic threshold, which likely prolonged the outbreak.