HIV-1 incidence rates in a community are a more accurate measure of epidemic trends than prevalence rates from surveillance, as they are not influenced by death rates, migration, or survey coverage. In Uganda, there have been encouraging reports of reductions in HIV-1 prevalence, but no reliable data exist for trends in incidence.
James Whitworth from the Medical Research Council Programme on AIDS in Uganda, and colleagues surveyed the adult population of 15 neighbouring villages for HIV-1 infection using annual censuses, questionnaires, and serological surveys.
HIV-1 incidence fell from 8.0 to 5.2 per 1000 person years at risk between 1990 and 1999. Incidence was 37% lower in the second half than the first half of the decade. HIV-1 prevalence fell significantly between the first and tenth annual survey rounds, especially among men aged 2024 years (6.5% to 2.2%) and 2529 years (15.2% to 10.9%). There were also substantial reductions in HIV-1 prevalence rates among women aged 1319 years (2.8% to 0.9%) and 2024 years (19.3% to 10.1%)
James Whitworth comments: "More than half a million people have died from AIDS in Uganda since the start of the epidemic, which still rages at unacceptably high rates throughout sub-Saharan Africa. However, our findings strengthen evidence from earlier studies of declines in HIV-1 prevalence and increases in risk-lowering sexual behaviour, and gives hope that AIDS control programmes can control the AIDS epidemic with messages about changes in behaviour."