Factors associated with treatment success and death in cases with multidrug-resistant tuberculosis in Bulgaria, 2009-2010

Abstract

Objective: To analyze determinants of success and death in multidrug-resistant tuberculosis patients (MDR-TB; resistance to, at least, isoniazid and rifampicin) placed on treatment in Bulgaria during the period September 2009 to March 2010 using logistic regression.

Results: Fifty MDR-TB patients started treatment. Male:Female ratio was 2.3:1; mean age 43 years (range: 18-77); 19 patients (38%) were new; median duration of disease before treatment was 5 years (range: 1-13). All patients tested negative for HIV. Eight cases had XDR-TB (MDR-TB plus resistance to any fluoroquinolone and any second-line injectable). Twenty-four months after starting treatment, 24 patients (48%) had a successful outcome, in 6 (12%) treatment failed, 19 (38%) died, and one (2%) interrupted treatment. XDR-TB cases experienced higher mortality than others (75% vs. 30.9%, respectively, P<0.05). Sputum smear positivity at start of treatment and weight loss or no weight gain were positively associated with death (adjusted Odds ratio: 5.16; 95% confidence interval: 1.16-22.84 and 5.61; 1.48-21.20, respectively) and negatively with success (0.13; 0.02-0.94 and 0.02; 0.00-0.19). No previous TB treatment increased likelihood of success (7.82; 1.09-56.15).

Discussion and conclusions: Most MDR-TB patients in this first treatment cohort using WHO-recommended norms had advanced disease explaining the high mortality and low success. Early, adequate treatment of MDR-TB patients can improve outcomes and avert transmission.

Keywords: Bulgaria; Extensively drug resistant tuberculosis (XDR-TB); Multidrug-resistant tuberculosis (MDR-TB); Treatment outcome; Tuberculosis (TB).