Risk of travel-associated tuberculosis.

Infection with Mycobacterium tuberculosis might be acquired at home or during travel. The risk is determined by exposure frequency to a source case and the duration of the exposure. Thus, whether travel increases the background risk depends on origin, destination, and duration of travel. Infection might be acquired indoors or outdoors, but the overall risk seems small, whatever the setting. Bacille Calmette-Guérin vaccination and preventive therapy have both been discussed as possible preventive interventions, but the disadvantages associated with both approaches appear to outweigh any benefits. Because the risk of acquisition of infection with M. tuberculosis is small, the most rational approach is likely to delay intervention until a traveler presents with clinically active tuberculosis, as is done with any other patient.