[Tuberculosis and immigration in a health sanitary area in Madrid, Spain. Trends in 1994-2003]. / Tuberculosis e inmigración en un área sanitaria de Madrid. Situación epidemiológica y evolución en la década 1994-2003.

BACKGROUND AND OBJECTIVE: To describe trends and epidemiological characteristics of immigrant and native populations with tuberculosis. POPULATION AND METHOD: Population-based, descriptive analysis of case data reported to the Regional Registry of Tuberculosis Cases from 1994 to 2003 living in the south of Madrid, Spain (755,202 inhabitants). RESULTS: The number of cases reported was 2211, of which 269 (12.1%) were foreign-born persons. Tuberculosis incidence declined from 46.6/100,000 in 1994 (2.9% immigrants) to 25.2/100,000 in 2003 (35.8% immigrants) (p < 0.001). Foreign-born persons with tuberculosis had come to Spain from Latin America-Caribbean (56%), Africa (30%) and Europe (11%). Of the foreign-born, 73.6% developed active tuberculosis within 5 years of arrival (50.9% within 2 years). CONCLUSIONS: The incidence of tuberculosis has declined in the study area but the tendency to decrease has come to a halt because of cases occurring among immigrants. Among those for whom the date of Spain entry was known, a half arrived 2 years or less prior to the diagnosis of tuberculosis. We stress that tuberculosis control programs must target such at-risk population.

[Patterns of tuberculosis transmission in a health area of Madrid]. / Patrones de transmisión de la tuberculosis en un área sanitaria de Madrid.

BACKGROUND: Employing molecular epidemiology techniques for the study of tuberculosis can afford the possibility of identifying tuberculosis transmission patterns. This study has been made for the purpose of estimating the incidence of tuberculosis related to recent transmission in Madrid and of identifying the risk factors making it possible to define transmission patterns. METHODS: A three-year descriptive populational study was conducted on patients diagnosed with tuberculosis based on cultures in four districts in Madrid (550,442 inhabitants). The transmission patterns were described by means of conventional epidemiological research and molecular techniques (Restriction Fragment Length Polymorphism--RFLP--analysis with IS6110 and spoligotyping). RESULTS: An RFLP analysis was conducted on 233 clinically isolated Mycobacterium tuberculosis strains, 99 (42.5%) of which were grouped into 29 clusters. The most numerous group was comprised of 134 patients infected with M. tuberculosis strains of a single RFLP pattern. These patients averaged 48.3 years of age (DE 19.4), and 17.2% were revealed to have an endogenous risk factor. Two transmission patterns were identified among the grouped cases. The first pattern included 57 patients pertaining to 23 small clusters (2-4 cases), 25 (43.9%) of which were epidemiologically linked to another case from the same cluster. The second pattern was comprised of 42 patients grouped into 6 large clusters (5 cases or more). The subjects averaged 31.4 years of age (DE 15.8), 28.6% being intravenous drug users, 31% infected with HIV, and 26.2% having a prison background. CONCLUSIONS: Identifying tuberculosis transmission patterns by using molecular biology techniques affords the possibility of detecting population groups for whom preferential measures can be taken in the prevention and control programs.