Drug-Resistant Tuberculosis among HIV-Infected Patients Starting Antiretroviral Therapy in Durban, South Africa

Kenneth A Freedberg,Matilda Mazibuko,Ingrid V Bassett,Rochelle P Walensky,Senica Chetty,Jenny Allen,Bingxia Wang,Jeffrey K Hom,Janet Giddy,Robert J Wilkinson,Elena Losina

doi:10.1371/journal.pone.0043281

Abstract

ObjectiveTo 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.DesignCross-sectional cohort study.MethodsConsecutive 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.Results1,035 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.ConclusionsThe 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.

Highlights

Infection with tuberculosis (TB) remains the leading cause of mortality among HIV-infected people worldwide [1]
Patients diagnosed with TB at Sinikithemba were offered TB treatment on-site, with fixed-dose regimens according to South African treatment guidelines [11]
One thousand thirty-five patients were enrolled for whom sputum culture was carried out, representing approximately 90% of patients commencing antiretroviral therapy (ART) literacy training during the study period

Summary

Introduction

Infection with tuberculosis (TB) remains the leading cause of mortality among HIV-infected people worldwide [1]. South Africa has the third highest TB incidence in the world, with ,1,000 cases per 100,000 people per year and the most HIV-infected citizens of any country [2,3]. Enhanced surveillance there revealed 39% MDR TB and 6% XDR TB among HIV-infected patients with culture-confirmed TB, exceeding previous surveys [7]. Province-wide surveillance in KwaZulu-Natal has largely reflected sputum cultures performed on request based on clinical suspicion of treatment failure. This practice has varied widely among districts, with an estimated 80% of reported cases lacking culture confirmation and drug susceptibility testing [8,9]. Individual-level data, such as prior TB treatment exposure and HIV status, have not been available in population-based surveys of TB drug resistance

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Conclusion