RESUMO
OBJECTIVE: To know the frequency of resistances of Mycobacterium tuberculosis and the associated factors. PATIENTS AND METHODS: Prospective study of the sensitivity of Mycobacterium tuberculosis by means of the method of the proportions of Canetti in the Hospital Arquitecto Marcide-Profesor Novoa Santos (Ferrol, Spain) among 1991 and 1998. A descriptive and multiple regression analyses were performed. RESULTS: Were studied 355 strains. Primary resistance: Isoniazid 1.1%, Streptomycin 1.1%. Secondary resistance: Isoniazid 11.6%, in the 5.2% existed multidrug-resistance. The risk factors for drug-resistant tuberculosis were previous treatment (odds ratio [OR] = 10.9; 95% CI, 2.9-39.4) and age higher than 40 years (OR = 3.9; 95% CI, 1.1-14.5). CONCLUSIONS: A low frequency of resistance was observed. The factors associated with the resistances were previous treatment and age.