OBJECTIVE: To know the frequency of resistances of Mycobacterium tuberculos
is 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 H
ospital 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%, Stre
ptomycin 1.1%. Secondary resistance: Isoniazid 11.6%, in the 5.2% existed m
ultidrug-resistance. The risk factors for drug-resistant tuberculosis were
previous treatment (odds ratio [OR] = 10.9; 95% CI, 2.9-39.4) and age highe
r than 40 years (OR = 3.9; 95% CI, 1.1-14.5).
CONCLUSIONS: A low frequency of resistance was observed. The factors associ
ated with the resistances were previous treatment and age.