Age-specific prevalence of and risk factors for anal human papillomavirus (HPV) among men who have sex with women and men who have sex with men: the HPV in men (HIM) study.

BACKGROUND: An increasing incidence of anal cancer among men suggests a need to better understand anal canal human papillomavirus (HPV) infection among human immunodeficiency virus-negative men.
METHODS: Genotyping for HPV was conducted on cells from the anal canal among men who have sex with women (MSW) and men who have sex with men (MSM), aged 18-70 years, from Brazil, Mexico, and the United States. Factors associated with anal HPV infection were assessed using multivariable logistic regression.
RESULTS: The prevalence of any HPV type and oncogenic HPV types did not differ by city. Anal canal HPV prevalence was 12.2% among 1305 MSW and 47.2% among 176 MSM. Among MSW, reporting a lifetime number of ≥ 10 female sex partners, a primary sexual relationship <1 year in duration, and a prior hepatitis B diagnosis were independently associated with detection of any anal HPV in multivariable analysis. Among MSM, a younger age, reporting ≥ 2 male anal sex partners in the past 3 months, and never using a condom for anal sex in the past 6 months were independently associated with detection of any anal HPV in multivariable analysis.
CONCLUSIONS: Number of sex partners was associated with anal HPV infection in both MSW and MSM. Anal HPV infection in men may be mediated by age, duration of sexual relationship, and condom use.