Drug-resistant tuberculosis, clinical virulence, and the dominance of the Beijing strain family in Russia

Abstract

Context: Tuberculosis and multidrug-resistant tuberculosis is a serious public health problem in Russia.

Objective: To address the extent of "Beijing strain" transmission in the prison/civil sectors and the association of drug resistance, clinical, and social factors with the Beijing genotype.

Design and setting: Cross-sectional population-based molecular epidemiological study of all civilian and penitentiary tuberculosis facilities in the Samara region, Russia.

Patients: Consecutively recruited patients with bacteriologically proven tuberculosis (n = 880).

Main outcome measure: Proportion of Beijing strains and association with drug resistance, human immunodeficiency virus infection, imprisonment, radiological, clinical, and other social factors.

Results: Beijing-family strains (identified by spoligotyping and composed of 2 main types by mycobacterial interspersed repetitive unit analysis) were predominant: 586/880 (66.6%; 95% confidence interval [CI], 63.4%-69.7%) with a significantly higher prevalence in the prison population (rate ratio [RR], 1.3; 95% CI, 1.2-1.5) and those aged younger than 35 years (RR, 1.2; 95% CI, 1.0-1.3). Comparable proportions were co-infected with the human immunodeficiency virus ( approximately 10%), concurrent hepatitis B and C (21.6%), drank alcohol ( approximately 90%), smoked ( approximately 90%), and had a similar sexual history. Drug resistance was nearly 2-fold higher in patients infected with Beijing strains compared with non-Beijing strains: multidrug resistance (RR, 2.4; 95% CI, 1.9-3.0), for isoniazid (RR, 1.8; 95% CI, 1.5-2.1), for rifampicin (RR, 2.2; 95% CI, 1.7-2.7), for streptomycin (RR, 1.9; 95% CI, 1.5-2.3), and for ethambutol (RR, 2.2; 95% CI, 1.6-3.2). Univariate analysis demonstrated that male sex (odds ratio [OR], 1.5; 95% CI, 1.1-1.9), advanced radiological abnormalities (OR, 3.3; 95% CI, 1.3-8.4), homelessness (OR, 5.6; 95% CI, 1.1-6.3), and previous imprisonment (OR, 2.0; 95% CI, 1.5-2.7) were strongly associated with Beijing-strain family disease. Multivariate analysis supported previous imprisonment to be a risk factor (OR, 2.0; 95% CI, 1.4-3.3) and night sweats to be less associated (OR 0.7; 95% CI, 0.5-1.0) with Beijing-strain disease.

Conclusions: Drug resistance and previous imprisonment but not human immunodeficiency virus co-infection were significantly associated with Beijing-strain infection. There was evidence that Beijing isolates caused radiologically more advanced disease.