Sufficient COVID-19 quarantine and testing on international travelers to forestall cross-border transmission after China's removal of the Zero-COVID policy in early 2023

Int J Infect Dis. 2024 May 13:107097. doi: 10.1016/j.ijid.2024.107097. Online ahead of print.

Abstract

Background: Removal of zero-COVID restrictions in China led to a surge in COVID-19 cases. In response, countries imposed restrictions on Chinese travelers. However, border policies imposed may not have been informed by accurate data and may not have provided substantial benefits.

Methods: We analyzed quarantines sufficient to prevent additional in-country transmission for February 13-19, 2023 based on World Health Organization (WHO) and self-reported infection rates to estimate prevalence.

Results: We have shown that self-reported prevalence data indicated more stringent border restrictions compared to WHO-published prevalence statistics. No travel restrictions were required for Singapore, South Korea, and Japan so that infections would not be greater than with complete border closure. However, a 1-day, 2-day, and 3-day quarantine were indicated for England, Germany, and Scotland respectively. A 10-day, 13-day, and 14-day quarantine were required for Italy, France, and the Philippines, respectively, to prevent an increase in within-country infections due to travel. Vietnam and Thailand required a complete border shutdown.

Conclusions: Our results demonstrated the necessity for accurate and timely reporting of pandemic statistics to prevent an increase in viral spread. Through the minimum-quarantine analysis, countries can use science to determine policy, minimize international friction, and improve the cost-efficiency of interventions.

Keywords: COVID-19; Epidemiology; Pandemics; Policy; Prevalence; World Health Organization.