The Risk of Aircraft-Acquired SARS-CoV-2 Transmission during Commercial Flights: A Systematic Review

Area of Science:

• Public Health
• Epidemiology
• Aviation Safety

Background:

• Aircraft-acquired transmission of SARS-CoV-2 presented a significant public health concern during the early pandemic.
• Understanding transmission dynamics on commercial flights is vital for mitigating airborne disease spread.

Purpose of the Study:

• To systematically review and analyze factors influencing SARS-CoV-2 transmission on commercial flights.
• To assess the impact of flight duration and masking on in-flight transmission rates.

Main Methods:

• Systematic review adhering to PRISMA guidelines, analyzing articles published from January 2020 to April 2021.
• Inclusion criteria focused on index cases and identifiable flight duration; exclusion criteria removed non-commercial flights and modeling studies.
• Analysis of 50 flights categorized by duration (short, medium, long) and as a continuous variable, using negative binomial regression.

Main Results:

• Compared to short flights, unmasked medium and long flights showed significantly increased SARS-CoV-2 incidence rates (4.66-fold and 25.93-fold increases, respectively).
• Long flights with enforced masking reported no in-flight transmission.
• Each additional hour of flight duration correlated with a 1.53-fold increase in the incidence rate ratio of cases.

Conclusions:

• Flight duration is a critical factor in SARS-CoV-2 transmission risk.
• Enforced masking on long-haul flights appears to be an effective measure to prevent in-flight transmission.
• Recommendations for public health policy include considering mandatory masking for extended air travel.