Tuberculosis risk factors and mortality for HIV-infected persons receiving antiretroviral therapy in South Africa.

OBJECTIVE: To determine important risk factors for and impact of tuberculosis on survival in HIV-infected patients starting antiretroviral therapy (ART) in South Africa. DESIGN: Prospective trial of 1771 HIV-infected patients with either CD4 cell count less than 200 cells/microl or a prior AIDS-defining illness, enrolled in randomized trial of four antiretroviral regimens. METHODS: Data collected from patient records. RESULTS: A history of tuberculosis at study entry was reported by 27% of patients and correlated with poor baseline health status. A history of tuberculosis at baseline was associated with subsequent tuberculosis and death during ART, but was not itself an independent risk factor for poor outcome. Tuberculosis was diagnosed during ART in 14% of patients and was more frequent during the first 3 months. Tuberculosis during therapy was independently associated with increased hazard of other AIDS-defining events and death, regardless of when during ART tuberculosis occurred. ART that consistently suppressed circulating viremia reduced but did not eliminate tuberculosis risk. CONCLUSION: In HIV-infected patients who started ART at low CD4 cell counts, tuberculosis at baseline was a predictor of death, but was not independent of other factors indicating poor baseline health status. Tuberculosis during follow-up was, in contrast, an independent predictor of death even after adjustments for baseline risk factors, including CD4 cell count and viral load. Virologic failure during ART was associated with a 55% increase in risk of tuberculosis. Thus, tuberculosis is a major marker for poor outcome both at baseline and during ART and is not completely eliminated by fully suppressive ART.

Detection of a substantial rate of multidrug-resistant tuberculosis in an HIV-infected population in South Africa by active monitoring of sputum samples.

BACKGROUND: Tuberculosis (TB) coinfection with human immunodeficiency virus (HIV) is a substantial problem in South Africa. There has been a presumption that drug-resistant strains of TB are common in South Africa, but few studies have documented this impression. METHODS: In Phidisa, a joint observational and randomized HIV treatment study for South African National Defence Force members and dependents, an initiative was launched to test subjects (by use of microbiologic TB test) who appeared to be at high risk. We report results for HIV-infected subjects. RESULTS: TB was identified by culture in 116 (19.9%) of 584 patients selected for sputum examination on the basis of suggestive symptoms. Smear was an insensitive technique for confirming the diagnosis: only 33% of culture-positive patients were identified by smear, with a 0.2% false-positive rate. Of the 107 culture-positive individuals with susceptibility testing, 22 (20.6%) were identified to be multidrug resistant (MDR), and 4 (3.7%) were identified to be extensively drug resistant. Culture-positive cases with a history of TB treatment had more than twice the rate of MDR than those without (27.1% vs 11.9%; P = .05). CONCLUSIONS: TB is common in this cohort of HIV-infected patients. Smear was not a sensitive technique for identifying culture-positive cases in this health system. Drug susceptibility testing is essential to proper patient management because MDR was present in 20.6% of culture-positive patients. Better management strategies are needed to reduce the development of MDR TB, because so many of these patients had received prior antituberculous therapy that was presumably not curative.