[Infection by resistant Mycobacterium tuberculosis in a hospital population. A longitudinal study of incidental cases at the Fundación Jiménez Díaz].

OBJECTIVE

Evaluation of epidemiologic, clinical and prognostic characteristics in cases of resistant tuberculosis (MRTB).

METHODS

Retrospective longitudinal and observational study of resistant cases of tuberculosis at Fundación Jiménez Díaz (1991-1997). Statistical analysis of conventional tests and significance level at p < 0.05.

RESULTS

Twenty patients out of 558 with recovery of Mycobacterium tuberculosis showed resistance to some drugs (isoniazid, rifampicin, ethambutol, streptomycin or pyrazinamide). Information was gathered from 19 patients: eight (42%) HIV-positive patients; eight (42%) with the antecedent of tuberculosis (2 abandoned treatment). There were eleven cases (58%) of secondary resistance and eight of primary resistance but only five (25%) with multi-resistance criteria (1 primary and 4 secondary); five cases showed primary resistance to isoniazid. The number of resistances and HIV seropositivity or antecedent of prophylaxis was not statistically significant. In contrast, the higher number of resistances and tuberculosis antecedent were indeed statistically significant.

CONCLUSIONS

There was a low resistance rate at our institution. All multi-resistant cases had antecedents of therapy or prophylaxis abandon or previous tuberculosis. Only one case was MRTB. The relevance of complying with a proper therapy is emphasized (consider therapies directly monitored if there is risk of abandon). In patients with epidemiologic risk factors susceptibility studies should be performed and also start therapy with four drugs. The objective is to decrease the percentages of resistance and morbi-mortality.