Treatment outcomes in new pulmonary tuberculosis cases depending on the main genotypes of <i>Mycobacterium tuberculosis</i> in the Republic of Sakha (Yakutia)

Abstract

The objective: to study treatment efficacy in new pulmonary tuberculosis patients depending on the genotypes of M. tuberculosis in the Republic of Sakha (Yakutia).Subjects and methods. The authors studied the clinical course and outcomes of 312 bacteriologically confirmed new pulmonary tuberculosis cases among patients admitted to hospital in 2010-2014. Molecular genetic tests included deletion analysis of RD105 and RD207 regions of DNA of the pathogen followed by MIRU-VNTR genotyping at 24 loci.Results. In the Republic of Sakha (Yakutia), the Bejing and S genotypes are of epidemic importance, these genotypes prevail among drug resistance mycobacteria. Tuberculosis caused by the Bejing genotype had multiple (MDR) and extensive drug resistance (XDR) in 30.6% of cases, its subtype CC2/W148 - in 85.3%. The S genotype was accompanied by MDR/XDR in 69.7% of cases, subtype S256 - in 78.9%. The treatment of patients was highly efficient according to the criteria of sputum conversion (92%) and cavities healing (89.4%). The lowest rates were observed in case of tuberculosis caused by the Bejing and S genotypes due to their subtypes CC2/W148 and S256. Clinical cure of new pulmonary tuberculosis caused by the Bejing genotype was achieved in 73.4% of cases, by subtype CC2/W148 - in 41.2% with a significantly higher proportion of treatment failures and lethal outcomes of tuberculosis than in other subtypes of this genotype. With the S genotype, the clinical cure was achieved in 72.7% of patients, with no significant difference in the incidence of unfavorable outcomes in patients with subtype S256.

Keywords

• туберкулез легких
• генотипы mycobacterium tuberculosis
• субтип cc2/w148
• субтип s256
• впервые выявленные больные
• исходы туберкулеза