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. Baseline anal HPV swabs were collected, and DNA typing was performed. One hundred and ninety-five participants, 76 (42%) from the US, had a mean age of 30.9 years (range 18-64). In 182 participants with results available, anal HPV infection was common with 169 (93%) with ≥1 type, 132 (73%) with ≥1 nine-valent vaccine types, and 66 (36%) with HPV 16. Participants in the US had a higher prevalence of HPV 16 (56%, p = 0.004) and HPV 6 (69%, p < 0.001) compared to the other regions. Stimulant drug use was significantly associated with HPV 6 detection. Anal HPV is highly prevalent in this population of MSM and TW sampled from four countries, with HPV 16 the most commonly detected type. The nine-valent HPV vaccine has the potential to provide significant protection if given prior to exposure.