The Effect of the Progressive Multi-Dimensional Policies on Imported COVID-19 Curtailment in China

Background: As countries are lifting restrictions and resuming international travels, the rising risk of COVID-19 importation remains concerning, given that the SARS-CoV-2 virus could be transmitted unintentionally through the global transportation network. To explore and assess the effective strategies for curtailing the epidemic risk from international importation nationwide, we evaluate the “Joint Prevention and Control” mechanism that China adopted, which was made up of nineteen containment policies including quarantine, nucleic acid testing (NAT), border closure and flight service adjustment. Methods: To illustrate how the multi-pronged policies affect the confirmation of imported COVID-19 cases, the change of diagnosis time of the cases from border arrival to a clinical confirmation were selected as the key variable. Based on 1,314 epidemiological-survey cases from February 29 to May 25, 2020 in China, we applied negative binomial regression models to predict how each policy is associated with the variation of the diagnosis time. We then compared the average means of the marginal effect of each policy before and after its implementation in different port-of-entry cities. Findings: We found that multi-dimensional interventional policies are effective, when they were implemented in a synchronized manner. Strategies, such as centralized quarantine and NAT, flight service adjustment and border closure, were found to facilitate an early identification of infected inbound case. Specifically, from arrival to clinical confirmation, a coordinated implementation of these aforementioned policies is associated with a maximum reduction in diagnosis interval up to 3×38 days, 2×35 days and 2×23 days, respectively. Interpretation: The study suggests that the prevention of a domestic spreading of COVID-19 from importation can be effective when the intervention polices are implemented in a timely, multi-dimensional and synchronized manner. Funding Statement: This research was supported by a research grant from the Sustainability Institute, The Ohio State University. Declaration of Interests: Authors declare no competing interests.