Abstract
Background: Sexually transmitted infections and inflammation in the female genital tract can increase the risk of HIV acquisition in women. Men who have sex with men (MSM) are often at increased risk of HIV infection due to behavioral and biological factors. In order to assess whether high-risk behavioral preferences associated with increased markers of immune activation, we recruited a cohort of high-risk HIV-negative MSM (unprotected sex, intravenous drug use) and compared markers of immune activation to low-risk HIV-negative males.