RESUMEN
BACKGROUND: Historically the district of Ciutat Vella in Barcelona has a high incidence of tuberculosis (TB) and, more recently, it is home to a considerable proportion of immigrants. OBJECTIVES: To determine the prevalence of tuberculous infection (TI) in a pediatric population from this district and evaluate the impact of immigration. METHODS: Children and adolescents aged < 16 years old were screened using the tuberculin skin test (TST) mainly in visits of the healthy child program. Proportions were compared using the x2 test and adjusted odds ratios were estimated through a logistic regression model. RESULTS: Six hundred ninety-nine children were studied. The overall prevalence of positive TST was 3.4 % (95 % CI: 2.2 %-5.1 %). Prevalence increased with age (P 5 0.009) from 1.9 % in children aged 1-5 years old to 6.4 % in children and adolescents aged 10-15 years. A total of 88.3 % of the immigrants had been vaccinated with BCG compared with 2.5 % of autochthonous children and adolescents (P < 0.001). The prevalence ratio between immigrants and autochthonous children was 2.1 (P 5 0.07). Three cases of TB disease were detected among children, but no index case was found in children with TI. CONCLUSIONS: The high TI prevalence found suggest that living in the district is a risk factor, which justifies routine TST screening of all the children living there. The present criteria for the interpretation of TST in immigrants vaccinated with BCG residing in areas of high incidence are dubious.
