Low rates of recurrence after successful treatment of multidrug-resistant tuberculosis in Tomsk, Russia.

SETTING: Tomsk, Russia, where multidrug-resistant tuberculosis (MDR-TB) is prevalent. OBJECTIVES: To report rates of recurrence following successful treatment of MDR-TB in a program providing individualized treatment regimens designed according to the current global standard of care. DESIGN: A retrospective cohort study of 408 adults successfully treated for pulmonary MDR-TB from 10 September 2000 to 1 November 2004, and followed for up to 6 years post-treatment. We used Poisson regression with generalized estimating equations to assess whether recurrence rates changed significantly with time. RESULTS: We analyzed 399 (97.5%) patients with at least one follow-up visit (15 850 person-months of observation [PMO]). Baseline resistance to second-line drugs was common (65.2%); 398 patients (99.7%) were human immunodeficiency virus (HIV) negative. In the first year of post-treatment follow-up, there were six episodes of recurrence (1.4/1000 PMO, 95%CI 0.5-3.0). After the first post-treatment year, there were 21 episodes of recurrence (1.8/1000 PMO, 95%CI 1.1-2.8). The rate did not change significantly with time. CONCLUSION: Individualized regimens designed according to the current global standard of care achieved low rates of MDR-TB recurrence among non-HIV-infected persons treated in a programmatic setting.

Barriers to successful tuberculosis treatment in Tomsk, Russian Federation: non-adherence, default and the acquisition of multidrug resistance.

OBJECTIVE: To identify barriers to successful tuberculosis (TB) treatment in Tomsk, Siberia, by analysing individual and programmatic risk factors for non-adherence, default and the acquisition of multidrug resistance in a TB treatment cohort in the Russian Federation. METHODS: We conducted a retrospective cohort study of consecutively enrolled, newly detected, smear and/or culture-positive adult TB patients initiating therapy in a DOTS programme in Tomsk between 1 January and 31 December 2001. FINDINGS: Substance abuse was strongly associated with non-adherence [adjusted odds ratio (OR): 7.3; 95% confidence interval (CI): 2.89-18.46] and with default (adjusted OR: 11.2; 95% CI: 2.55-49.17). Although non-adherence was associated with poor treatment outcomes (OR: 2.4; 95% CI: 1.1-5.5), it was not associated with the acquisition of multi-drug resistance during the course of therapy. Patients who began treatment in the hospital setting or who were hospitalized later during their treatment course had a substantially higher risk of developing multidrug-resistant TB than those who were treated as outpatients (adjusted HRs: 6.34; 95% CI: 1.35-29.72 and 6.26; 95% CI: 1.02-38.35 respectively). CONCLUSION: In this cohort of Russian TB patients, substance abuse was a strong predictor of non-adherence and default. DOTS programmes may benefit from incorporating measures to diagnose and treat alcohol misuse within the medical management of patients undergoing TB therapy. Multidrug-resistant TB occurred among adherent patients who had been hospitalized in the course of their therapy. This raises the possibility that treatment for drug-sensitive disease unmasked a pre-existing population of drug-resistant organisms, or that these patients were reinfected with a drug-resistant strain of TB.