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

The effectiveness of quarantine (i.e. lockdown) measures to prevent the spread of an epidemic due to a novel infectious pathogen where no vaccine is available has often been a subject of debate [7] [8] [9] . Under ordinary circumstances, border control efforts do not go beyond entry screening. However, during the epidemic of severe acute respiratory syndrome (SARS) in 2002-3, although entry screening at airports and other key locations was adopted in most countries its effectiveness was estimated to be very limited due to the relatively long incubation period and low prevalence of SARS, which resulted in extremely low positive predictive values at screening locations [10] [11] [12] [13] . In the ongoing COVID-19 epidemic, many countries have accompanied regular entry screening with a drastic changes in travel restrictions. Although the effectiveness of entry screening is likely very limited as already shown elsewhere [14] , the epidemiological impact of the change in movement restrictions has yet to be explicitly evaluated.