Drug-resistant tuberculosis among HIV-infected patients starting antiretroviral therapy in Durban, South Africa.

OBJECTIVE

To estimate the prevalence of drug-resistant tuberculosis (TB) and describe the resistance patterns in patients commencing antiretroviral therapy (ART) in an HIV clinic in Durban, South Africa.

DESIGN

Cross-sectional cohort study.

METHODS

Consecutive HIV-infected adults (≥ 18y/o) initiating HIV care were enrolled from May 2007-May 2008, regardless of signs or symptoms of active TB. Prior TB history and current TB treatment status were self-reported. Subjects expectorated sputum for culture (MGIT liquid and 7H11 solid medium). Positive cultures were tested for susceptibility to first- and second-line anti-tuberculous drugs. The prevalence of drug-resistant TB, stratified by prior TB history and current TB treatment status, was assessed.

RESULTS

1,035 subjects had complete culture results. Median CD4 count was 92/µl (IQR 42-150/µl). 267 subjects (26%) reported a prior history of TB and 210 (20%) were receiving TB treatment at enrollment; 191 (18%) subjects had positive sputum cultures, among whom the estimated prevalence of resistance to any antituberculous drug was 7.4% (95% CI 4.0-12.4). Among those with prior TB, the prevalence of resistance was 15.4% (95% CI 5.9-30.5) compared to 5.2% (95% CI 2.1-8.9) among those with no prior TB. 5.1% (95% CI 2.4-9.5) had rifampin or rifampin plus INH resistance.

CONCLUSIONS

The prevalence of TB resistance to at least one drug was 7.4% among adults with positive TB cultures initiating ART in Durban, South Africa, with 5.1% having rifampin or rifampin plus INH resistance. Improved tools for diagnosing TB and drug resistance are urgently needed in areas of high HIV/TB prevalence.