Work

Effect of containment strategies for respiratory diseases on infections imported via international travel to the USA: a modelling study

Year: 2026

Type: article

Abstract: Objectives To examine outcomes from respiratory pathogens containment strategies focused on international travellers. Design We developed a compartmental model generalisable to respiratory infectious diseases, in which international travellers interact with each other and airline/airport workers during transit. We used SARS-CoV-2 Omicron surge data (basic reproduction number (R 0 ): 9.5) as a case example and performed sensitivity and scenario analyses, including varying the R 0 for different respiratory pathogens. Settings A US high-volume airport. Participants Simulated international travellers and airline/airport workers. Interventions Projection of new and imported SARS-CoV-2 infections without intervention ( No Intervention ); pre-travel screening for travellers who intend to travel (intended travellers) with PCR ( Pre-travel PCR ); or antigen testing ( Pre-travel Ag ); mask-wearing guidance for travellers and workers ( Mask-wearing ); and a Combined strategy ( Pre-travel PCR & Mask-wearing ). Outcome measures The number of new and imported respiratory disease infections over the 90-day simulation period. Results Over the 90-day simulation, the number of infected travellers entering the USA would be: 1 155 580 (27.2% of 4.2 million (M) intended travellers) with No Intervention ; 709 560/4.2M (16.7%) with Pre-travel PCR ; 862 330/4.2M (20.3%) with Pre-travel Ag ; 1033 820/4.2M (24.4%) with Mask-wearing ; and 650 480/4.2M (15.3%) with Combined . The number of new infections among airline/airport workers would be: 25 670 (73.3% of 35 000 workers) with No Intervention ; 25 260 (72.2%) in Pre-travel PCR ; 25 590 (73.1%) in Pre-travel Ag ; 24 630 (70.4%) in Mask-wearing ; and 18 770 (53.6%) in Combined . In scenario analyses, the most impactful parameters were R 0 of the respiratory pathogen and population immunity level. Conclusions A Combined strategy of pre-travel PCR testing and mask-wearing would most effectively reduce respiratory infection among international travellers and airline/airport workers, but would still allow a substantial number of infections to enter the USA, especially when the pathogen is highly transmissible.

Source: BMJ Open

DOI: 10.1136/bmjopen-2025-105013