Abstract

DESIGN AND

OBJECTIVES:

Potential risk factors for recurrence of tuberculosis (TB) were investigated in a retrospective cohort study of 305 human immunodeficiency virus (HIV) positive and 984 HIV-negative South African gold miners treated for TB with directly-observed, rifampicin-based regimens. Standard treatment changed from rifampicin, isoniazid and pyrazinamide (RHZ) to RHZ plus ethambutol (RHZE) during the study period.

RESULTS:

Recurrence occurred in 37 HIV-positive and 46 HIV-negative men. HIV infection was associated with a significantly higher recurrence rate (8.2 vs 2.2 per 100 person-years; multivariate-adjusted incidence rate ratio [IRR] 4.9, 95% confidence interval [CI] 3.0-8.1), as were post-tuberculous scarring (multivariate-adjusted IRR 1.6 for one or two scarred lung zones, 4.0 for three or more zones; test for trend P < 0.001) and drug resistance (multivariate-adjusted IRR 2.7, 95%CI 1.01-7.4). The recurrence rate was significantly higher following treatment with RHZ than RHZE (multivariate-adjusted IRR 2.1, 95%CI 1.1-4.0). The difference between regimens needs to be interpreted with caution, however, as allocation was not randomised.

CONCLUSION:

The high recurrence rate among HIV-positive men requires further investigation to distinguish relapse from re-infection as the predominant cause, leading to consideration of further intensification of the initial regimen or use of secondary prophylaxis.