Risk of infection with Mycobacterium tuberculosis in travellers to areas of high tuberculosis endemicity

• Published in: The Lancet (British edition) 2000-08, Vol.356 (9228), p.461-465
• Main Authors: Cobelens, Frank GJ, van Deutekom, Henk, Draayer-Jansen, Inez WE, Schepp-Beelen, Ank CHM, van Gerven, Paul JHJ, van Kessel, Rob PM, Mensen, Marlies EA
• Format: Article
• Language: English
• Subjects: Adult; Bacterial diseases; Biological and medical sciences; Endemic Diseases; Genetic markers; Global Health; Health care; Health risk assessment; Health risks; Health services; Human bacterial diseases; Humans; Infectious diseases; Local population; Medical sciences; Preventive medicine; Prospective Studies; Public health; Risk factors; Skin; Skin Tests; Travel; Tuberculosis; Tuberculosis - diagnosis; Tuberculosis - epidemiology; Tuberculosis and atypical mycobacterial infections; Vaccines
• ISSN: 0140-6736; 1474-547X
• DOI: 10.1016/S0140-6736(00)02554-X

No data exist on risks of infection with Mycobacterium tuberculosis in travellers. We studied incidences of and risk factors for tuberculin skin-test conversion among Dutch long-term travellers to countries of high tuberculosis endemicity. In a multicentre, prospective cohort study based in travel and tuberculosis clinics in the Netherlands, 1072 BCG-naïve immunocompetent travellers to countries with an estimated annual risk of M tuberculosis infection of at least 1% were skin tested before departure with 1 tuberculin unit purified protein derivative (PPD) of M tuberculosis in Tween-80. Those with results less than 2 mm were retested 2–4 months after their return with simultaneous testing for cross-sensitivity to environmental mycobacteria (1 tuberculin unit PPD of M scrofulaceum in Tween-80). M tuberculosis infection was defined as a post-travel M tuberculosis tuberculin skin-test result of at least 10 mm that was 3 mm or more larger than the M scrofulaceum result. Post-travel skin-test results were available for 656 (66%) of 988 individuals who were eligible for follow-up. Among these, 12 M tuberculosis infections were identified (1·8%). The overall incidence rate was 3·5 per 1000 person-months of travel (95% Cl 2·0–6·2), and 2·8 per 1000 person-months of travel (1·2–5·5) after exclusion of health-care workers. Two had active tuberculosis at the time of testing (incidence rate 0·6 per 1000 person-months of travel [0·3–2·3]). Work in patient care abroad was an independent risk factor (adjusted rate ratio 5·34, p=0·015). The risk of M tuberculosis infection in long-term travellers to high-endemicity countries, even if not engaged in health-care work, is substantial and of similar magnitude to the average risk for the local population. BCG vaccination or post-travel tuberculin skin-testing of high-risk travellers should be considered.