Prevalence and determinants of anal human papillomavirus infection in men who have sex with men and transgender women.

Human papillomavirus (HPV) prevalence varies by population. This study investigated anal HPV type detection risk by country in a population of men who have sex with men (MSM) and transgender women (TW) at risk of HIV. Sexually active HIV-1-uninfected MSM and TW were enrolled at eight sites: four in the United States (US), two in Thailand, one in Peru, and one in South Africa.