Assessing the spread risk of COVID-19 associated with multi-mode transportation networks in China

The spatial spread of COVID-19 during early 2020 in China was primarily driven by outbound travelers leaving the epicenter, Wuhan, Hubei province. Existing studies focus on the influence of aggregated out-bound popula-tion flows originating from Wuhan; however, the impacts of different modes of transportation and the network structure of transportation systems on the early spread of COVID-19 in China are not well understood. Here, we assess the roles of the road, railway, and air transportation networks in driving the spatial spread of COVID-19 in China. We find that the short-range spread within Hubei province was dominated by ground traffic, notably, the railway transportation. In contrast, long-range spread to cities in other provinces was mediated by multiple factors, including a higher risk of case importation associated with air transportation and a larger outbreak size in hub cities located at the center of transportation networks. We further show that, although the dissemination of SARS-CoV-2 across countries and continents is determined by the worldwide air transportation network, the early geographic dispersal of COVID-19 within China is better predicted by the railway traffic. Given the recent emergence of multiple more transmissible variants of SARS-CoV-2, our findings can support a better assessment of the spread risk of those variants and improve future pandemic preparedness and responses.

Automated summary

The early spatial spread of COVID-19 in China during early 2020 was mainly driven by outbound travelers from Wuhan. Previous studies have focused on the influence of outbound population flows from Wuhan, but the role of different transportation modes and network structures in the spread of COVID-19 is not well understood. This study examines the impact of road, railway, and air transportation networks on the spread of COVID-19 in China. It finds that short-range spread within Hubei province was primarily influenced by railway transportation, while long-range spread to other provinces was influenced by multiple factors, including air transportation and larger outbreak size in hub cities.