High rates of incident and prevalent anal human papillomavirus infection among young men who have sex with men.

BACKGROUND: There are few published estimates of anal human papillomavirus (HPV) infection rates among young men who have sex with men (YMSM). METHODS: We estimated incidence and prevalence of type-specific anal HPV infection using clinician-collected anal swabs for HPV DNA testing obtained during a 1-year prospective study of 94 YMSM (mean age, 21 years) in Seattle. RESULTS: Seventy percent of YMSM had any HPV infection detected during the study, and HPV-16 and/or -18 were detected in 37%. The incidence rate for any new HPV infection was 38.5 per 1000 person-months and 15.3 per 1000 person-months for HPV-16/18; 19% had persistent HPV-16/18 infection. No participant tested positive for all 4 HPV types in the quadrivalent vaccine. The number of lifetime male receptive anal sex partners was significantly associated with HPV infection. The prevalence of HPV-16/18 was 6% among YMSM with a history of 1 receptive anal sex partner and 31% among YMSM with ≥ 2 partners. CONCLUSIONS: Although the high prevalence of HPV among YMSM highlights the desirability of vaccinating all boys as a strategy to avert the morbidity of HPV infection, most YMSM appear to remain naive to either HPV-16 or -18 well into their sexual lives and would benefit from HPV immunization.