As African countries scale up couples HIV testing, little is known about sexual behaviors and HIV risk for HIV uninfected partners in known HIV serodiscordant relationships.
We conducted a prospective study of 3,380 HIV serodiscordant partnerships from 7 African countries. Self-reported sexual behavior data were collected quarterly from HIV uninfected partners.
The proportion of HIV uninfected partners reporting sex with their known primary HIV infected partner decreased during follow-up (from 93.5% in the prior month at baseline to 73.2% at 24 months, p<0.001). Simultaneously, an increasing proportion reported sex with an outside partner (from 3.1% to 13.9%, p<0.001). A small proportion (<5%, stable throughout follow-up) reported sex with the infected partner and an outside partner in the same month (concurrent). Unprotected sex was more common with outside partners than with their primary known HIV infected partners (risk ratio 4.6; 95% CI 4.2–5.2). HIV incidence was similar for those reporting sex only with their primary HIV infected partner compared to those who reported an outside partner (2.87 vs. 3.02 per 100 person-years, p=0.7), although those who had outside partners were more likely to acquire HIV that was virologically distinct from that of their primary partner (p<0.001).
For uninfected members of HIV serodiscordant couples, sex with the infected partner declined as sex with outside partners increased, likely reflecting relationship dissolution and risk shifting from a known infected partner. Risk reduction messages for HIV uninfected partners in serodiscordant partnerships should include strategies to reduce HIV acquisition from outside partners.
Keywords: HIV serodiscordant couples, sexual behavior, condom use