SEROPREVALENCE AND INCIDENCE OF SEXUALLY-TRANSMITTED DISEASES IN A RURAL UGANDAN POPULATION

The aim of the study was to determine in a rural population the age- a nd sex-specific prevalence and incidence rates of serological reactivi ty of 5 common sexually transmitted diseases (STDs) and their associat ion with HIV-1 antibody status. Of the adult population of two village s (529 adults aged 15 years or more) 294 provided an adequate blood sp ecimen both on enrolment and at 12 months. The sera were tested at 3 c ollaborating laboratories for antibodies against HIV-1, Treponema pall idum, Haemophilus ducreyi, Chlamydia trachomatis and herpes simplex vi rus type 1 (HSV-1) and type 2 (HSV-2). A sample of 45 children were te sted for HSV-1 and HSV-2. Seroprevalence rates in adults on enrolment were 7.8% for HIV-1, 10.8% for active syphilis, 10.4% for H. ducreyi, 66.0% for C. trachomatis, 91.2% for HSV-1 and 67.9% for HSV-2. Males w ere significantly more likely than females to be seropositive for H. d ucreyi (15.6% versus 6.6%), but less Likely to be HSV-2 antibody posit ive (57.0% versus 74.4%). Reactivity to H. ducreyi, C. trachomatis and HSV-2 rose with increasing age. In contrast, active syphilis showed n o age trend. All STDs tended to be more common in those HIV-1 seroposi tive. Incidence rates over the 12 months were nil for HIV-1, 0.5% for syphilis, 1.2% for H. ducreyi, 11.3% for C. trachomatis, and 16.7% for HSV-2. The results of this exploratory study indicate that all STDs i ncluded are common in this rural population. The high HSV-2 prevalence rate among adolescents suggests that HSV-2 may be an important risk f actor for HIV-1 infection. HSV-2 serology may be a useful tool to moni tor sexual behaviour interventions in young people.