The effect of travel restrictions on the spread of the 2019 novel coronavirus (2019-nCoV) outbreak

Matteo Chinazzi; Jessica T. Davis; Marco Ajelli; Corrado Gioannini; Maria Litvinova; Stefano Merler; Ana Pastore y Piontti; Luca Rossi; Kaiyuan Sun; Cécile Viboud; Xinyue Xiong; Hongjie Yu; M. Elizabeth Halloran; Ira M. Longini; Alessandro Vespignani

Even in presence of the above limitations, the analysis of the Wuhan 2019-nCoV outbreak and the modeling assessment of the effects of travel limitations could be instrumental to national and international agencies for public health response planning. We show that by January 23 2020, the epidemic had already spread to other cities within China. The travel quarantine around Wuhan has only modestly delayed the epidemic spread to other areas of China. This is in agreement with separate studies on the diffusion of the 2019-nCoV virus in China (29; 21; 30). The model indicates that while the Wuhan travel ban was initially effective at reducing international case importations, the number of cases observed outside China will resume its growth after 2-3 weeks from cases that originated elsewhere. Furthermore, the modeling study shows that additional travel limitations up to 90% of the traffic have a modest effect unless paired with public health interventions and behavioral changes that achieve a considerable reduction in the disease transmissibility (31). The above results provides data with potential uses for the definition of optimized containment schemes and mitigation policies that includes the local and international dimension of the 2019-nCoV epidemic.