Abstract

Objectives
This study aimed to validate the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, identify infection risk factors among air passengers subject to a 14-day mandatory quarantine, and evaluate the accuracy of mass symptom-based screening criteria at an airport.
Methods
This retrospective cohort study analyzed data from 116 004 air passengers who entered Thailand through Suvarnabhumi Airport in Bangkok from April 2020 to September 2020. The incidence of SARS-CoV-2 infection, risk characteristics, and accuracy indices of symptom-based screening were calculated.
Results
The overall incidence of SARS-CoV-2 was 0.5%, or 540 infections per 100 000 air passengers. Identified risk factors included sex, nationality, continent of departure, on-arrival screening results, and month of travel. Positive screening results indicated a higher risk and positive likelihood ratio for SARS-CoV-2 infection. However, the on-arrival screening criteria demonstrated low sensitivity and area under the receiver operating characteristic curve.
Conclusions
The current study confirms previous findings that the risk of SARS-CoV-2 infection during air travel is low. However, this might result from strict pre-departure screening and the SARS-CoV-2 test requirement for arriving passengers. The symptom-based screening criteria used upon arrival showed a low probability of identifying positive cases, suggesting that incorporating additional criteria could help detect asymptomatic infections. The integrated screening and quarantine model proved effective in preventing the spread of the virus into local communities.

• Keywords: SARS-CoV-2, COVID-19, Screening, Quarantine, Travel medicine, Epidemiology