Reciprocal sex partner concurrency is associated with greater risk for sexually transmitted infections among heterosexuals at high-risk for HIV

Background: The relationship of reciprocal sex partner concurrency (RSPC) (both participants in a sexual relationship have other sex partners) to sexually transmitted infection (STI) risk among heterosexuals is examined. Methods: Participants were recruited from high-HIV-risk neighborhoods in New York City, 2006–2007, and interviewed about their STI diagnoses and sexual risk behaviors (e.g., condom use) in the prior 12 months and with their last opposite-sex sex partner. RSPC is when the participant and her/his last opposite-sex partner both had other sex partners during their sexual relationship in the prior 12 months. Adjusted odds ratios (AOR) and 95% Confidence Intervals (95%CI) were estimated by conditional logistic regression, stratified by sex exchange involvement and controlling for sexual risk behaviors, number of sex partners, drug/alcohol use, and sociodemographics. Results: Participants (N=722) were: 52% female, predominantly black (75%) or Hispanic (18%), with a mean age of 36.0 years; 25% exchanged sex, 23% self-reported any STIs, 8.0% tested HIV positive, and 40% reported RSPC. Among participants with RSPC, 32% self-reported any STIs vs. 18% of those with no RSPC (OR [RSPC vs. no RSPC] =1.8, 95%CI=1.2-2.6). In the multivariate analysis, any self-reported STIs was significantly associated with RSPC (vs. no RSPC) (AOR=1.6, 95%CI=1.1-2.4), unprotected anal sex (AOR=1.6, 95%CI=1.1-2.4), and female gender (AOR=2.0, 95%CI=1.3-3.0). Conclusions: Heterosexuals in high-HIV-risk urban neighborhoods who engage in RSPC are at greater risk of STIs and, potentially, HIV. RSPC, in addition to sexual risk behaviors, may increase HIV infection risk through STI cofactors and linkage into larger HIV/STI sexual transmission networks.