The association of tuberculosis and HIV infection in Harare, Zimbabwe.

Setting: The tuberculosis (TB) service responsible for all TB treatment in Harare, Zimbabwe.

Objectives: (1) To determine HIV seroprevalence among TB patients and controls. (2) To compare clinical and demographic characteristics of HIV-infected and uninfected TB patients.

Design: Cohort study. Entry criterion: TB diagnosed during the 18 month study period. Assessment included HIV serology. Matched community controls were HIV serotested.

Results: In 1434 TB patients tested, HIV seroprevalence was 48% in men and 44% in women, peaked in the 25-34 year age group and was higher than in controls (relative risk [RR] = 3.1, 95% confidence interval [CI] = 2.6-3.7). In adults, seroprevalence was 34%, 49% and 58% in successive 6 month periods. A history of entry of prior TB treatment was less common in the HIV-seropositive (RR = 0.57, CI = 0.37-0.88). In adults, tuberculin negativity, TB at 2 sites, lymph node, pericardial and miliary TB, hilar adenopathy and pleural effusion were significantly more common in HIV-seropositive patients; cavitation and upper lobe involvement were significantly less frequent. Pulmonary TB and sputum smear positivity had similar frequencies in the 2 groups.

Conclusion: HIV was strongly and increasingly associated with TB in Harare and altered the clinical and radiologic features of TB. Failed standard TB treatment in HIV-infected individuals contributed minimally to new cases of TB.