Group Sex and Prevalent Sexually Transmitted Infections Among Men Who Have Sex with Men

We evaluated the direct relation between group sex and prevalent sexually transmitted infections (STI) in a cross-sectional study of men who have sex with men (MSM) presenting at an urban STI clinic in the Midwestern US. Among 231 men who enrolled and reported that they have sex with men, we collected behavioral data using a combination of interviewer and self-administered surveys and extracted STI data from electronic health records. We used modified Poisson regression to examine the unadjusted and adjusted associations between group sex participation and prevalent STI. One-quarter of participants (n = 58) reported group sex participation in the last 3 months. Eighteen percent of participants (n = 42) had gonorrhea and 19 % (n = 45) had chlamydial infection. Men who reported recent group sex were more likely to be HIV-positive, to report recent drug use, and to report unprotected receptive anal intercourse in the past 3 months. After adjustment for age, race, and recent drug use, recent participation in group sex was associated with prevalent gonorrhea infection (prevalence ratio [PR] = 2.11, 95 % confidence interval [CI] = [1.13, 3.95]) but not chlamydia infection (PR = 1.03, 95 % CI = [0.58, 1.84]). We performed a sensitivity analysis in which we also adjusted for unprotected receptive anal intercourse and the results were not substantively changed. In summary, participation in group sex in the past 3 months was associated with a more than twofold increased prevalence of gonorrhea, but not with chlamydia. These findings support group sex participation as a potential contributor to increased STI prevalence.