Assessing the impact of reduced travel on exportation dynamics of novel coronavirus infection (COVID-19)

Asami Anzai; Tetsuro Kobayashi; Natalie M. Linton; Ryo Kinoshita; Katsuma Hayashi; Ayako Suzuki; Yichi Yang; Sungmok Jung; Takeshi Miyama; Andrei R. Akhmetzhanov; Hiroshi Nishiura

We considered the impact of reduced travel volumes on COVID-19 transmission dynamics outside China. Specifically, we quantified the impact on: (i) the number of exported cases, (ii) the probability of a major epidemic, and (iii) the time delay to a major epidemic. Figure 1 shows the observed number of infections in and outside China. The first exported case in Thailand was reported on 13 January 2020. Assuming the epidemic start date is set at 1 December 2019 (Day 0), the city of Wuhan was put in lockdown from Day 53 (or 23 January 2020). Considering that the mean incubation period of COVID-19 approximately 5 days, the impact of reduced travel volumes would start to be interpretable from Day 58 (28 January 2020). We used data from Day 43 (13 January) onwards. Because the first case diagnosed outside China was reported on that day. author/funder, who has granted medRxiv a license to display the preprint in perpetuity.