Seroprevalence and incidence of genital ulcer infections in a rural Ugandan population

Objectives: To determine age-sex specific seroprevalence and incidence rate s of Treponema pallidum, Haemophilus ducreyi, and HSV-2; to assess the asso ciation between HIV-1 status and incidence of these STIs; and HSV-2 serosta tus with number of lifetime sexual partners. Methods: Antibodies against HIV-1, T pallidum, H ducreyi, and HSV-2 infecti ons were tested using approximately 1000 paired (2 year interval) sera coll ected from a rural adult (15-54 years) population cohort in south west Ugan da. Results: Overall HIV-1 prevalence was 4.9%. Prevalence for T pallidum was 1 2.9% among males and 12.6% among females. The corresponding rates for H duc reyi were 9.8% and 7.3% respectively. HSV-2 prevalence rates were considera bly lower in males (36.0%) than in females (71.5%), p <0.001. Incidence rat es for T pallidum per 1000 person years of observation were 8.4 for males a nd 12.3 for females. The corresponding rates for H ducreyi were 21.6 and 20 .0 and for HSV-2 were 73.2 and 122.9 per 1000 person years of observation, respectively. The RR of HSV-2 incidence was 3.69 in HIV seropositive cases versus HIV seronegative after adjusting for age and sex. The corresponding RR for H ducreyi was 3.50 among female HN positive cases versus negatives w ith no effect seen in males. Association between HIV-1 prevalence and preva lence of other STIs was significant (Mantel-Haenszel test) for H ducreyi (p =0.01) and for HSV-2 (p=0.004) but not for T pallidum (p >0.4). HSV-2 preva lence was associated with number of lifetime sexual partners (females, p=0. 003; males, p=0.08). Conclusions: The results have provided a reliable estimate of the magnitude of the STI problem and demonstrated an association between HIV-1 status an d serology of other STIs in a general rural population in sub-Saharan Afric a. The study has also highlighted a correlation between HSV-2 seropositivit y and number of reported lifetime sexual partners.