Enrollment characteristics of study population at date of sample collection.

a–cHIV seropositive (HIV pos) and HIV seronegative (HESN) women and their HIV serodiscordant male partners were evaluated for demographic data and sexual risk-taking profiles. In addition, HIV seronegative women (Low-risk) living with an HIV seronegative male partner were included (male participants in the Low-risk study group were not assessed for demographic parameters). In total, complete demographic data sets were available from 288 of the 300 women whose CVS samples were assessed for immunological parameters.dSTIs: sexually transmitted infections.ePSA: Prostate-specific antigen (>1 ug/ml of CVS) as a sign of recent unprotected sexual intercourse.