Molecular epidemiology of tuberculosis in the Tula area, Central Russia, before the introduction of the Directly Observed Therapy Strategy

Abstract

Tuberculosis remains a major public health concern in Russia and worldwide. Given the great geographical, ethnic, and socio-economic heterogeneities between Russian regions, epidemiological data cannot be generalized from a regional to a country-wide level. We present data on the epidemiology of tuberculosis in Central Russia. We report a high level of resistance to major antitubercular drugs in both new and previously treated patients in the region. The level of drug resistance in new cases was almost twice as high as the estimated average national level. The Mycobacterium tuberculosis strains that circulated in the region were predominantly represented by LAM-RUS and Beijing genotypes. These two lineages were strongly associated with drug resistance and clustering. Using molecular epidemiology techniques, we showed a high interpenetration by M. tuberculosis strains between the prison and civilian populations. A limited number of identical strains were responsible for the majority of drug-resistant tuberculosis cases in both settings.

Prevalence of Latin-American-Mediterranean genetic family in population structure of Mycobacterium tuberculosis in Bulgaria

“…Since cavitary TB is associated with a higher sputum-bacillary load, this finding supports the hypothesis that RD-Rio M. tuberculosis is associated with a more ''severe'' disease as a strategy to increase transmission, at least in some ethnic groups [5]. Secondly, LAM-RUS sublineage in central Russia (along with the Beijing genotype) was shown to be associated with MDR and clustering: the level of drug resistance in new cases was almost twice as high as the estimated average national level [2]. In the present study, 2 of the 4 isolates with a single LAM-specific PCR fragment were MDR, while two others were susceptible.…”

“…A number of studies demonstrated an association with drug resistance of the Latin-American-Mediterranean (LAM) family [2][3][4]. On the other hand, other studies have shown high transmissibility of this strain, but not a significant association with increased virulence [5,6].…”

Insights into the Origin, Emergence, and Current Spread of a Successful Russian Clone of Mycobacterium tuberculosis

“…In contrast, the Beijing genotype is found at a 40 to 60% frequency across Russian regions, which is far from the overwhelming dominance. Furthermore, other genetic families of M. tuberculosis in Russia, such as the LAM family, were suggested to be linked to MDR (41). An increased circulation of Beijing strains (compared to strains of other M. tuberculosis genotypes) in prison environments has been demonstrated in most, but not all, settings (see reference 36 and references therein).…”

“…B0/W148 isolates constituted 37.2% of drug-resistant Beijing strains in Estonia, while no susceptible B0/W148 isolates were found in that study, which enrolled strains isolated in 1994 (29). More recently, B0/ W148 isolates were found to be associated with multidrug resistance in an epidemiologically meaningful subsample of newly diagnosed patients in St. Petersburg, in northwestern Russia (P Ͻ 0.0001) (26), and the Tula oblast, in central Russia (P ϭ 0.01) (41). In Abkhazia, 22 of 23 B0/W148 isolates were MDR, while other Beijing genotype isolates included a notable number of pansusceptible isolates (10 of 55 isolates) (51).…”

“…In particular, a 74.8% rate of prevalence of the Beijing family in the studied population was found (compared to an average 50% rate among pulmonary TB patients across Russia [16,27,[36][37][38][39][40][41][42][43][44][45][46][47][48]). At the same time, the rate of B0/W148 in the Beijing population was 30% (35).…”