Objective: To assess trends in HIV-1 infection rates and changes in sexual behaviour over 7 years in rural Uganda.
Methods: An adult cohort followed through eight medical–serological annual surveys since 1989–1990. All consenting participants gave a blood sample and were interviewed on sexual behaviour.
Results: On average, 65% of residents gave a blood sample at each round. Overall HIV-1 prevalence declined from 8.2% at round 1 to 6.9% at round 8 (P = 0.008). Decline was most evident among men aged 20–24 years (11.7 to 3.6%;P < 0.001) and women aged 13–19 (4.4% to 1.4%;P = 0.003) and 20–24 (20.9% to 13.8%;P = 0.003). However, prevalence increased significantly among women aged 25–34 (13.1% to 16.6%;P = 0.04). Although overall incidence declined from 7.7/1000 person-years (PY) in 1990 to 4.6/1000 PY in 1996, neither this nor the age-sex specific rates changed significantly (P > 0.2). Age-standardized death rates for HIV-negative individuals were 6.5/1000 PY in 1990 and 8.2/1000 PY in 1996; corresponding rates for HIV-positive individuals were 129.7 and 102.7/1000 PY, respectively. There were no significant trends in age-adjusted death rates during follow-up for either group. There was evidence of behaviour change towards increase in condom use in males and females, marriage at later age for girls, later sexual debut for boys and a fall in fertility especially among unmarried teenagers.
Conclusions: This is the first general population cohort study showing overall long-term significant reduction in HIV prevalence and parallel evidence of sexual behaviour change. There are however no significant reductions in either HIV incidence or mortality.
From the aMedical Research Council Programme on AIDS in Uganda, Uganda Virus Research Institute, Entebbe, Uganda and the bDepartment of Public Health, Institute of Health Science, University of Oxford, Oxford, UK.
Requests for reprints to: Dr A Kamali, Medical Research Council Programme on AIDS in Uganda, Uganda Virus Research Institute, PO Box 49, Entebbe, Uganda.
Received: 9 November 1999; accepted: 2 December 1999.