Objective: To describe the role of men and women as sources of HIV transmission and to estimate HIV incidence among discordant couples resident in diverse rural communities in Uganda.
Setting: Rakai, a rural district in Uganda, East Africa.
Methods: A population-based cohort study, which has been conducted as annual serological and behavioral surveys since 1989. Community clusters were stratified into trading centers on main roads, intermediate trading villages on secondary roads and agricultural villages off roads. In the 1990 survey round, serological data were available for 79 discordant and 411 concordant HIV-negative couples aged 13-49 years. The present analysis examines sex-specific seropositivity associated with place of residence and the incidence of seroconversion among discordant couples between 1990 and 1991.
Results: Seventy-nine discordant couples were followed; the HIV-positive partner was male in 44 couples (57%) and female in 35 couples (43%). There was marked variation in the sex of the seropositive partner by place of residence: women were the HIV-positive partner in 57% of couples from trading centers, 52% from intermediate villages, and 20% from agricultural communities (P < 0.008). Condom use was higher in discordant couples in which the man was the uninfected partner (17.1%) rather than the woman (9.5%). HIV-positive women, but not HIV-positive men, reported significantly more sexual partners and more genital ulcers than seronegative individuals of the same sex. Seroincidence rates among men and women in discordant relationship were 8.7 and 9.2 per 100 person-years (PY), respectively, which was much higher than in concordant seronegative couples (men, 0.82; women, 0.87 per 100 PY).
Conclusions: In this Ugandan population, men are the predominant source of new infections in rural villages. Risk factors and preventive behaviors vary with the sex of the infected partner, and seroconversion rates are similar in both sexes.
PIP: The analysis of marital relationships in rural Uganda in which one partner is infected with human immunodeficiency virus (HIV) revealed important information about the social dynamics of HIV transmission. As part of an ongoing cohort study of over 3000 adults in southwestern Uganda's Rakai district, data were collected on 79 discordant couples. The HIV-infected partner was male in 44 couples (57%) and female in 35 couples (43%). In the trading centers and intermediate trading villages, women were more likely to be the HIV-infected partner (57% and 52%, respectively); in rural areas, however, the male partner was the HIV carrier in 80% of discordant couples. 14.3% of women in female HIV-positive compared to only 2.1% of those in male HIV-positive discordant relationships reported two or more sexual partners in the year preceding the interview; there was no significant difference on this factor among HIV-positive and HIV-negative men (48.8% and 45,7%, respectively). 17.1% of seronegative men with HIV-infected wives compared to only 9.5% of seropositive men with seronegative wives used condoms with their partner. During the one-year study period, the rate of seroconversion was 8.7/100 years of observation for men and 9.2 for women. Extrapolation of the data from this study to the district as a whole suggests that 18.7% of couples have at least one HIV-infected member. Needed are campaigns to promote monogamy and condom use, particularly among men from rural areas who travel to high prevalence trading areas.