Testing the concurrency hypothesis: HIV incidence among married couples in two population-based cohort studies in rural Uganda

Concurrent partnerships are often considered a primary driver of the HIV epidemic in Sub-Saharan Africa. Due to data constraints, however, few studies have been able to demonstrate its effect using empirical data. In this paper, we test whether HIV transmission rates are higher for individuals with concurrent partners - an effect that is ascribed to the higher viral load shortly after seroconversion. Data spanning a 14-year time period are pooled from two rural community sero-surveillance sites in south-Western Uganda. Sero-concordant negative married couples are followed over time, examining the risk of seroconversion for couples exposed to concurrency. A discrete-time hazard model is used to determine the risk of seroconversion among women whose husbands reported a concurrent partnership. We are unable to detect an effect of the husband’s concurrency on the HIV incidence of their wives. Our preliminary findings are in support of a growing body of literature that casts doubt on the role of concurrency for the spread of HIV.