Drug resistance of Mycobacterium tuberculosis strains isolated from patients with pulmonary tuberculosis in Archangels, Russia

Abstract

Setting: The Archangels oblast, Russia, 1998-2000.

Objective: To study Mycobacterium tuberculosis resistance to anti-tuberculosis drugs in the Archangels oblast, and to reveal risk factors for the development of drug-resistant tuberculosis.

Design: The drug susceptibility of strains isolated from 119 patients with pulmonary tuberculosis was studied using the BACTEC method. Medical records of the patients were reviewed, retrospectively, to identify factors associated with drug resistance.

Results: Sixty-seven strains (56.3%) were resistant to at least one anti-tuberculosis drug. The highest rates of resistance were observed for streptomycin and isoniazid: respectively 40.4% and 66.7% of strains isolated from newly and previously treated patients were resistant to streptomycin, and respectively 37.1% and 73.3% of strains isolated from newly and previously treated patients were resistant to isoniazid. Thirty of the 119 strains (25.2%) were multidrug-resistant. Multidrug resistance was four times higher among previously treated patients than among new patients. A history of previous or interrupted treatment for tuberculosis and being female were significantly associated with drug resistance.

Conclusion: Drug-resistant tuberculosis is an important problem in the Archangels oblast, Russia. The spread of drug resistance is attributed to several risk factors. Being female and evidence of previous treatment for tuberculosis are risk factors for the development of drug-resistant tuberculosis in the Archangels oblast. Patients with drug-resistant tuberculosis also showed a higher risk of interrupting their treatment.