Transmission of SARS-CoV 2 During Long-Haul Flight

Abstract

To assess the role of in-flight transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we investigated a cluster of cases among passengers on a 10-hour commercial flight. Affected persons were passengers, crew, and their close contacts. We traced 217 passengers and crew to their final destinations and interviewed, tested, and quarantined them. Among the 16 persons in whom SARS-CoV-2 infection was detected, 12 (75%) were passengers seated in business class along with the only symptomatic person (attack rate 62%). Seating proximity was strongly associated with increased infection risk (risk ratio 7.3, 95% CI 1.2-46.2). We found no strong evidence supporting alternative transmission scenarios. In-flight transmission that probably originated from 1 symptomatic passenger caused a large cluster of cases during a long flight. Guidelines for preventing SARS-CoV-2 infection among air passengers should consider individual passengers' risk for infection, the number of passengers traveling, and flight duration.

Keywords: 2019 novel coronavirus disease; COVID-19; SARS-CoV-2; air travel; aircraft; coronavirus disease; respiratory infections; severe acute respiratory syndrome coronavirus 2; transmission; viruses; zoonoses.

Figure 1

Seating location of passengers on Vietnam Airlines flight 54 from London, UK, to Hanoi, Vietnam, on March 2, 2020, for whom severe acute respiratory syndrome coronavirus 2 infection was later confirmed.

Figure 2

Epidemiologic and clinical timeline for passengers on Vietnam Airlines flight 54, from London, UK, to Hanoi, Vietnam, March 2, 2020, for whom SARS-CoV-2 infection was later confirmed. Because the flight arrived quite early in the morning (5:20 am), we considered the remainder of the day (19 h) to be the day of arrival. Case 14 traveled with a companion who was tested but negative for SARS-CoV-2 infection. SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.