Concurrent sexual partnerships among young adults in Cape Town, South Africa: how is concurrency changing?

BACKGROUND The current debate about the role of concurrent sexual partnerships in the spread of HIV is influenced by limited or weak empirical data on concurrency. There is still uncertainty about the most basic statistics and little is known about how concurrency is changing. METHODS Longitudinal data (n=2958) with repeated concurrency measures were employed to examine the prevalence of individual concurrency (someone has other partners during their most recent sexual partnership) and perceived partner concurrency (someone perceives his or her partner to have other partners) by population group and gender in 2005 and 2009. Individual fixed-effects logit regression models were created to examine factors associated with changes in individual concurrency among Black men and women. RESULTS The prevalence of individual concurrency increased among Black men who reported having had sex (from 33% in 2005 to 39% in 2009), remained constant among Black women (14%), decreased among Coloured (mixed-race) men (from 16% to 8%) and remained low among Coloured women (2% in 2005 and 1% in 2009). Overall, a small decrease in perceived partner concurrency was observed. Changes in individual concurrency were positively associated with changes in perceived partner concurrency among men and women. Among Black women, decreases in household income and finding employment increased the odds of reporting a positive change in individual concurrency. CONCLUSIONS Race and gender differences in concurrency should be taken into account in future research and HIV prevention initiatives. High and increasing levels of concurrency within most recent partnerships among Black men highlight this group as a potential focus for such efforts.