Levels of Protection across Concurrent Sexual Partnerships

A large body of research has found that sexual partner concurrency increases the transmission of sexually transmitted infections, including HIV. Researchers are now calling for further investigation into the types of concurrency that promote or impede onward transmission of STIs. In this paper, we use life history data collected from youth in urban Kisumu, Kenya, to examine levels of protection within concurrencies, defined by combinations of sexual intercourse and condom use. We find that approximately one-third of concurrency episode months were completely protected by consistent condom use and/or no sexual intercourse, and thus the large majority of months were not protected and therefore at some risk of STI transmission. Regression results show that mutual concurrency is more likely to display full protection for females and longer concurrencies, which are thought to increase transmission potential, are more likely to be protected among both females and males.