[Resistant Mycobacterium tuberculosis strains from immigrants in the community of Madrid: current assessment]

Immigration to Spain from countries with high rates of tuberculosis infection is increasing. The aim of this study was to describe and analyze resistance to antituberculosis drugs in strains isolated from foreign-born patients in the Community of Madrid.

A cohort of immigrants was identified at 14 hospitals in the Community of Madrid. To assess the sensitivity of isolated strains, we used the MGIT 960 system and/or the proportion method of Canetti. Clinical and sociodemographic information was recorded for each patient. We compiled descriptive statistics and performed univariate analysis, followed by multiple logistic regression analysis.

From a total of 312 cases, 268 strains were isolated. Sensitivity was tested in 221 strains. The proportion of immigrants with no health care coverage was 19.9%. Thirty-one strains (14.0%) were resistant; 24 (12.6%) were in newly diagnosed cases and 6 (27.3%) were in patients who had been treated previously. Ten strains (4.5%) were multidrug resistant. Resistance to isoniazid was detected in 18 strains (9.5%). Multidrug resistance was associated with a history of prior antituberculosis treatment (odds ratio, 5.94; 95% confidence interval, 1.46-24.18).

Barriers to health care faced by immigrants with tuberculosis should be removed. Treatment should begin with 4 drugs while the results of sensitivity tests are pending. A history of prior antituberculosis treatment should raise a suspicion of multidrug resistance.