Risk of severe acute respiratory syndrome-associated coronavirus transmission aboard commercial aircraft.

Background: Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) was introduced to the United States through air travel. Although the risk of SARS-CoV transmission within aircraft cabins has been addressed by several studies, the magnitude of the risk remains unclear.
Methods: We attempted to contact all persons with working US telephone numbers aboard seven US-bound flights carrying SARS patients. Consenting participants responded to a questionnaire, and a serum sample was collected at least 38 days after the flight and tested for SARS-CoV-associated antibodies. Participants reporting an illness compatible with SARS, with onset during the 2- to 10-day incubation period, were considered suspect cases; positive serology was required for confirmed cases.
Results: Among 1,766 passengers and crew, 339 (19%) persons were contacted. Of these, 312 (92%) completed questionnaires, and blood was collected from 127 (37%). Serology was negative for all 127 participants, including three of four who met the clinical case criteria for SARS, and the fourth had a mild illness that lasted only 5 days.
Conclusions: Transmission of SARS-associated CoV was not observed, suggesting that the risk of transmission is not amplified aboard aircraft.