Three air travel-related contact investigations associated with infectious tuberculosis, 2007-2008

The potential for transmission of Mycobacterium tuberculosis during air travel has garnered considerable attention in the media and among public health authorities due to high-profile cases of international travelers with infectious tuberculosis (TB).

During 2007 and 2008, state and local health officials were asked to locate and conduct diagnostic follow-up for airline passengers considered contacts of three travelers, two with multidrug-resistant (MDR) TB and one considered highly contagious, who undertook air travel while infectious with TB disease.

Public health departments in 21 states located and evaluated 79 (60%) of the 131 passenger contacts identified; 52 (40%) were lost to follow-up. Eight (10%) contacts had a history of TB disease or latent TB infection and were not retested. Sixteen (23%) of 71 contacts tested had positive TB test results suggesting latent TB infection, 15 of whom were from countries reporting estimated TB disease rates of greater than 200 cases/100,000 persons.

Passenger contacts' positive test results may represent prior TB infection acquired in their countries of residence or may be a result of new TB infection resulting from exposure during air travel.