Association of tuberculin sensitivity in Dutch adults with history of travel to areas of with a high incidence of tuberculosis

International travel may be a source of introduction of tuberculosis into l ow-incidence countries. We assessed whether, in The Netherlands, sensitivit y to tuberculin was associated with a history of travel to countries with a high incidence of tuberculosis. Immunocompetent adults with no history of Bacille Calmette-Guerin vaccination or sensitivity to tuberculin were skin- tested simultaneously with 1-tuberculin unit (TU) purified protein derivati ve (PPD) of Mycobacterium tuberculosis and 1-TU sensitin of Mycobacterium s crofulaceum. Tuberculin sensitivity was defined as a reaction to PPD of gre ater than or equal to 10 mm that was greater than or equal to3 mm larger th an the reaction to M. scrofulaceum sensitin. Tuberculin sensitivity was fou nd in 7 (0.7%) of 1014 participants (95% confidence interval [CI], 0.3%-1.4 %); it was independently associated with a cumulative history of > 3-months ' travel to high-incidence areas (odds ratio, 6.0; 95% CI, 1.2-31.2; P=.016 ) and increased in association with total duration of travel (P=.02). Trave l to high-incidence areas increases the risk of tuberculin sensitivity and, consequently, of latent tuberculous infection. In countries with a low inc idence of tuberculosis, cases of infection acquired during travel may accou nt for a substantial proportion of new infections in the resident populatio n.