Prevalence and co-occurrence of sexually transmitted infections among heterosexual couples in southern Uganda: a...

Partner-level sexually transmitted infection (STI) data from eastern Africa are rare, despite high STI burden. To address this gap, we examined STI prevalence and clustering among cohabiting couples in two high HIV-burden Ugandan communities, representing the largest population-based, couple-level STI study in the region.

We analysed data from the Sexually Transmitted Infection Prevalence Study (STIPS), a cross-sectional, population-based study in southern Uganda which tested participants for chlamydia, gonorrhoea, trichomonas, syphilis, high-titre syphilis and herpes simplex virus-2 (HSV-2). We restricted the present analysis to STIPS participants in a cohabiting sexual relationship. Poisson regression with robust standard errors was used to estimate prevalence ratios (PRs) and corresponding 95% confidence intervals (CIs) of all STIs by partner's infection status.

Among 423 cohabiting heterosexual couples, at least one partner tested positive for a curable STI (chlamydia, gonorrhoea, trichomonas or high-titre syphilis) in 37% of couples. STIs were strongly clustered within partner dyads. For example, female participants with male partners with gonorrhoea had increased prevalence of not only gonorrhoea (PR 10.4, 95% CI 6.4 to 16.8) but also HIV (PR 2.2, 95% CI 1.5 to 3.2), chlamydia (PR 2.5, 95% CI 1.1 to 5.7), trichomonas (PR 2.4, 95% CI 1.2 to 4.7) and HSV-2 (PR 1.3, 95% CI 1.1 to 1.7).

Partners of individuals with an STI are more likely to have a curable STI, which may be the same or may be a different pathogen; broad screening of partners could be essential to curbing transmission and preventing reinfection. Comprehensive couple-based approaches, including partner notification, treatment and counselling strategies, are critical for reducing STI disease burden.