title: Survival of civilian and prisoner drug-sensitive, multi- and extensive drug- resistant tuberculosis cohorts prospectively followed in Russia.
abstract: OBJECTIVE
  A long-term observational study was conducted in Samara, Russia to assess the survival and risk factors for death of a cohort of non-multidrug resistant tuberculosis (non-MDRTB) and multidrug resistant tuberculosis (MDRTB) civilian and prison patients and a civilian extensive drug-resistant tuberculosis (XDRTB) cohort.
  
  
  RESULTS
  MDRTB and XDRTB rates of 54.8% and 11.1% were identified in the region. Half (50%) of MDRTB patients and the majority of non-MDRTB patients (71%) were still alive at 5 years. Over half (58%) of the patients died within two years of establishing a diagnosis of XDRTB. In the multivariate analysis, retreatment (HR = 1.61, 95%CI 1.04, 2.49) and MDRTB (HR = 1.67, 95%CI 1.17, 2.39) were significantly associated with death within the non-MDR/MDRTB cohort. The effect of age on survival was relatively small (HR = 1.01, 95%CI 1.00, 1.02). No specific factor affected survival of XDRTB patients although median survival time for HIV-infected versus HIV-negative patients from this group was shorter (185 versus 496 days). The majority of MDRTB and XDRTB strains (84% and 92% respectively) strains belonged to the Beijing family. Mutations in the rpoB (codon 531 in 81/92; 88.8%), katG (mutation S315T in 91/92, 98.9%) and inhA genes accounted for most rifampin and isoniazid resistance respectively, mutations in the QRDR region of gyrA for most fluroquinolone resistance (68/92; 73.5%).
  
  
  CONCLUSIONS
  Alarmingly high rates of XDRTB exist. Previous TB treatment cycles and MDR were significant risk factors for mortality. XDRTB patients' survival is short especially for HIV-infected patients. Beijing family strains comprise the majority of drug-resistant strains.
authors.affiliation: Queen Mary College, Barts and the London School of Medicine, University of London, London, United Kingdom. y.balabanova@qmul.ac.uk
authors.forename: Yanina
authors.initials: Y
authors.lastname: Balabanova
authors.forename: Vladyslav
authors.initials: V
authors.lastname: Nikolayevskyy
authors.forename: Olga
authors.initials: O
authors.lastname: Ignatyeva
authors.forename: Irina
authors.initials: I
authors.lastname: Kontsevaya
authors.forename: Clare M
authors.initials: CM
authors.lastname: Rutterford
authors.forename: Anastasiya
authors.initials: A
authors.lastname: Shakhmistova
authors.forename: Nadezhda
authors.initials: N
authors.lastname: Malomanova
authors.forename: Yulia
authors.initials: Y
authors.lastname: Chinkova
authors.forename: Svetlana
authors.initials: S
authors.lastname: Mironova
authors.forename: Ivan
authors.initials: I
authors.lastname: Fedorin
authors.forename: Francis A
authors.initials: FA
authors.lastname: Drobniewski
mesh_terms: D000328:Adult; D003710:Demography; D024901:Drug Resistance, Multiple, Bacterial; D054908:Extensively Drug-Resistant Tuberculosis / Q000188:drug therapy / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009154:Mutation / Q000235:genetics; D011329:Prisoners / Q000706:statistics & numerical data*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012426:Russia / Q000453:epidemiology; D013997:Time Factors