title: Impact of immigration on tuberculosis infection among Canadian-born schoolchildren and young adults in Montreal.
abstract: We conducted a cross-sectional tuberculin survey among non-BCG-vaccinated Canadian-born schoolchildren in grades 6 and 10, health professional students, and young adult workers, to estimate the association of tuberculin reactions with indices of contact with tuberculosis. Participants underwent simultaneous tuberculin testing with PPD-T (standard) and PPD-B (from M. intracellulare). Exposure was estimated from questionnaire responses, group, aggregate census, and tuberculosis incidence data. Of 3,710 participants, 88 (2.4%) had positive tuberculin reactions, i.e., of 10+ mm. Positive tuberculin reactions were rarely associated with larger reactions to PPD-B, but were associated with older age (adjusted odds ratio for each 5 years: 1.5 [95% confidence interval, 1.3, 1.8]), household contact (4.2 [1.4, 12.7]), and population group (health professional versus all others: 0.6 [0.3, 1.0]). Estimated annual risk of infection declined by 3% per year. Tuberculin reactions were not associated with any indices of contact in school, work or neighborhood settings with foreign-born from tuberculosis endemic areas, nor with tuberculosis in Canadian-born. There was no evidence of transmission of tuberculosis from affected high risk sub-groups in Montreal to the general population working or attending school.
authors.affiliation: Department of Medicine, Montreal Chest institute, Quebec, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Menzies
authors.forename: C H
authors.initials: CH
authors.lastname: Chan
authors.forename: B
authors.initials: B
authors.lastname: Vissandjée
mesh_terms: D000293:Adolescent; D000328:Adult; D001500:BCG Vaccine; D002648:Child; D003430:Cross-Sectional Studies; D004641:Emigration and Immigration; D005260:Female; D006282:Health Personnel; D006801:Humans; D015994:Incidence; D008297:Male; D015269:Mycobacterium avium Complex / Q000276:immunology; D009790:Occupations; D015995:Prevalence; D011792:Quebec / Q000453:epidemiology; D012307:Risk Factors; D014373:Tuberculin / Q000276:immunology; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission
chemical_list: D001500:BCG Vaccine; D014373:Tuberculin