Background: We investigated the likelihood of transmission of tuberculosis (TB) from a highly infectious passenger with pulmonary/laryngeal TB to other persons aboard two airline flights, each approximately 1.25 h in duration.
Methods: The 146 passengers with known U.S. residence and 15 flight crew were contacted and referred to their personal health care provider or local health department for a Mantoux tuberculin skin test (TST). Each person was asked to complete a risk factor questionnaire and return this form with TST information provided by the health care provider.
Results: Questionnaires and TST results were obtained for 110 passengers (75%) and 10 crew (67%). Twenty passenger TST's were excluded from the analysis: 10 were self-read; one was not read in millimeters of induration; 8 were read after 72 h of being placed; and 1 was performed on a person suspected of being anergic. A positive TST was defined as > or = 5 millimeters of induration. Five passengers were found to be TST positive. There were no positive TST's identified among flight crewmembers. Each of the TST positive individuals had a risk factor for a positive TST. The TST positive individuals were seated throughout the plane, and each was seated at least 5 rows away from the passenger with infectious TB.
Conclusion: Although the possibility of transmission cannot be excluded, the findings of our investigation support a low likelihood of TB transmission during the study flights.