Trend in HIV prevalence among tuberculosis patients in Tanzania, 1991-1998

To determine the trend in human immunodeficiency virus (HIV) prevalence among tuberculosis patients in Tanzania and estimate what proportion of the increase in notification rates between the surveys was directly attributable to HIV infection.

Consecutive tuberculosis patients were enrolled over 6-month periods in most regions. Demographic and clinical data were collected on standard forms and a single HIV ELISA test performed. Trends in tuberculosis incidence were estimated from regional notification data.

Of 10612 eligible tuberculosis patients, 44% had HIV infection, compared with 32% in the previous survey. The largest increase was observed in the youngest birth cohorts, suggesting active HIV transmission. Approximately 60% of the increase in notification rates of smear-positive tuberculosis between surveys was directly attributable to HIV infection.

The HIV epidemic has had a strong influence on tuberculosis incidence. However, since 1995, tuberculosis notification data have increased less steeply, AIDS notifications have gone down, and HIV prevalence in blood donors has not increased a great deal. Another survey among tuberculosis patients in 5 years' time may show whether the HIV epidemic in Tanzania has reached a maximum or steady state.