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.     

Incidence of Aspergillus flavus in roasted and raw groundnuts from supermarkets and other vendors in Pietermaritzburg,South Africa and its management using biological control agents

This study was carried out to investigate the incidence of the aflatoxin-producing fungus, Aspergillus flavus in commercially available roasted and raw groundnuts sold by various vendors. Secondly, the study evaluated the antagonistic activity of Bacillus isolates against A. flavus in vitro and in vivo. All the 42 groundnut samples collected from the various vendors were contaminated with A. flavus. There was no significant difference (p > 0.05) in the incidence of A. flavus contamination in roasted and raw groundnut samples. The results of the in vitro bioassay indicated that the Bacillus isolates inhibited the growth of A. flavus ranging from 61 to 76%. In the in vivo study using groundnut kernels, increase in incubation time and concentration of the Bacillus isolates enhanced control of A. flavus. We showed that Bacillus isolates from the phyllosphere of ryegrass has potential as biocontrol agent for the control of A. flavus in groundnuts.