ArticlesRisk of infection with Mycobacterium tuberculosis in travellers to areas of high tuberculosis endemicity
Introduction
International travel and migration increase the spread of infectious diseases such as cholera, dengue, and AIDS.1, 2 Tuberculosis—a disease still highly endemic in large parts of the world—also has the potential for introduction into and further transmission within countries where it has become rare.3 Of particular concern is the spread of drugresistant strains.4 International travellers to highendemicity areas have received little attention as a possible source of introduction of tuberculosis. In some countries where vaccination with BCG is not given routinely, including the Netherlands, selected travellers are routinely advised to have tuberculin skin tests to identify recent infections. Compliance with such screening programmes is low, and little is known about cost-effectiveness, primarily because of lack of data on the risk of Mycobacterium tuberculosis infection during international travel.5, 6 The risk of tuberculosis in travellers is difficult to determine, because of the wide range in incubation periods of active infection, the low lifetime risk of active disease after infection, differences in background prevalence of latent infections, and the limited specificity of tuberculin testing after vaccination with BCG and in populations with high rates of non-specific reactions.7, 8, 9, 10 To quantify the risk of M tuberculosis infection in international travel, we estimated the rate of tuberculin skin-test conversion in a multisite cohort of BCG-naïve, skin-test-negative Dutch travellers who intended to stay for 3–12 months in areas of high tuberculosis endemicity.
Section snippets
Study population
All travellers born in the Netherlands after Dec 31, 1944, and who were at least 15 years old were eligible if they had not received BCG vaccination and intended to travel for a period of 3–12 months to countries highly endemic for tuberculosis. Such countries were defined as those with a reported or estimated annual incidence of tuberculosis of 1% or more.11 BCG status was ascertained by history, inspection for typical scars, and, in case of doubt, checking against the BCG registry. Exclusion
Results
Of 1072 individuals initially included, 988 were eligible for follow-up (figure). A post-travel M tuberculosis PPD result was available for 656 (66·4%). Of these, 616 (93·9%) were done with 1 tuberculosis unit PPD, and 40 with 2 tuberculosis units Rt23; an M scrofulaceum PPD post-travel test result was available for 618 (94·2%). For 32 individuals (4·9%), results of M tuberculosis PPD tests done elsewhere were used. Seven post-travel tests were repeated (1·1%). The mean age of the 656
Discussion
The risks of latent M tuberculosis infection in travellers found in this study, both overall and for non-health-care workers (3·5 and 2·8 per 1000 person-months of travel), are similar to those of hepatitis A in holiday makers or of malaria in tourists to Kenya, but are several-fold higher than the incidence rates of most other vaccine-preventable infections, including typhoid fever, cholera, and meningococcal disease.1, 14, 15, 16, 17 For non-health-care workers, the average annual incidence
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2022, The Lancet Infectious DiseasesReasons for seeking care and adherence to pretravel preparation in expatriate or long-term travelers’ children in the tropics: A French prospective study
2022, Travel Medicine and Infectious DiseaseCitation Excerpt :This emphasizes the need for a policy including vaccination with the BCG in at risk expatriate children [5,9,28]. In France, there are no recommendations on systematically testing expatriates for latent tuberculosis infection before and after a long-term stay, as suggested by several authors, irrespective of the method for screening, e.g., skin-test or interferon-gamma release assays (IGRA) [9,21,29]. Not all tropical diseases are infectious.
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