Abstract:
Background—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.
Methods—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.
Results—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 primaryknown 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).
Conclusion—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.
