Background Anal intercourse (AI) is associated with increased HIV and STI risk. Anal douching and use of AI lubrication may increase susceptibility to infection and may influence results of trials of microbicides for HIV prevention through effects on the rectal environment and on adherence to investigational microbicidal products. We measured the frequency of heterosexual AI, anal practices and lubricant use and their association with HIV and HSV-2 infection among women.

Methods Between October 2008 and June 2009, we recruited women age 18 years and older in Los Angeles. At the enrolment visit and at the 12-month visit, participants underwent a self-administered, web-based questionnaire covering demographic factors, sexual Behaviours, and anal practices. HSV-2 was diagnosed by IgG ELISA, and HIV was diagnosed by rapid ELISA with confirmation by Western blot. Here we report data collected during the enrolment visit.

Results We enrolled 141 women (34% identified as White, 40% Black, 26% Hispanic; the median age was 33 years (IQR=25–44)). Overall, 71% reported ever having AI, and 8% reported AI as current means of contraception. Overall, 18% reported AI over the past month, and among these women, the median number of monthly AI acts was 2 (IQR=1–3), 50% reported unprotected AI, 8% reported anal douching, and 58% reported using lubricant during AI. Commercial lubricants (38%), saliva (23%), petroleum jelly (15%), and lotion (12%) were the most commonly reported lubricants. The prevalence of HIV was 27% and HSV-2 was 57%. In multivariable analysis, AI was associated with testing positive for HIV (aOR=7.8 (95% CI=1.6 to 37.6)) and HSV-2 infection (aOR=3.3 (95% CI=1.2 to 9.1)) controlling for age, race, and lifetime sexual partners.

Conclusion AI is associated with HSV-2 and HIV infection, and anal douching and use of anal lubricating products not specifically designed for intercourse is common among women. The frequency and health effects of anal practices and lubricants warrant further study.