Primary Multidrug-Resistant Mycobacterium tuberculosis in 2 Regions, Eastern Siberia, Russian Federation

Svetlana Zhdanova¹, Scott K. Heysell¹

, Oleg Ogarkov, Galina Boyarinova, Galina Alexeeva, Suporn Pholwat, Elena Zorkaltseva, Eric R. Houpt, and Eugeniy Savilov

Author affiliations: Russian Academy of Medical Sciences, Irkutsk, Russian Federation (S. Zhdanova, O. Ogarkov, E. Savilov); University of Virginia, Charlottesville, Virginia, USA (S.K. Heysell, G. Boyarinova, S. Pholwat, E.R. Houpt); Regional TB-Prevention Dispensary, Irkutsk (O. Ogarkov, E. Zorkaltseva); Research Practice Center for Phthisiatry, Yakutsk, Russian Federation (G. Alexeeva); State Medical Continuing Education Academy, Irkutsk (E. Zorkaltseva, E. Savilov)

Abstract

Of 235 Mycobacterium tuberculosis isolates from patients who had not received tuberculosis treatment in the Irkutsk oblast and the Sakha Republic (Yakutia), eastern Siberia, 61 (26%) were multidrug resistant. A novel strain, S 256, clustered among these isolates and carried eis-related kanamycin resistance, indicating a need for locally informed diagnosis and treatment strategies.

In 2010, tuberculosis (TB) prevalence in the Russian Federation was 136 cases per 100,000 population; the estimated proportion of multidrug resistance, defined as resistance to isoniazid and rifampin in the absence of prior treatment (primary MDR TB), was 18% (1). However, at the subnational level, primary MDR TB might be highly variable; in oblasts or republics with continuous surveillance data, drug resistance varies from 5.4% to 28.3% (2). These data are predominantly from the western half of the country and do not include eastern Siberia.
In 2009, in the Irkutsk oblast in eastern Siberia, TB prevalence was 373 cases per 100,000 population and HIV prevalence was among the highest in the Russian Federation (3,4). In contrast, in the sparsely populated neighboring Sakha Republic (Yakutia), TB prevalence was lower (188 cases/100,000 population) and HIV was thought to be scarce (4). Molecular typing has found that more than half of the Mycobacterium tuberculosis isolates from the Russian Federation are the Beijing genotype, a pandemic lineage associated with MDR phenotype and characteristic drug-resistance mutations; prevalence of this genotype in Irkutsk is high (5,6). However, such investigation has not been performed in Yakutia. Given the distinct sociocultural patterns between Irkutsk and Yakutia, we hypothesized that the molecular epidemiology and drug-resistance patterns of M. tuberculosis from patients with primary MDR TB would be regionally distinct.