Race and prevalence of human papillomavirus infection among men residing in Brazil, Mexico and the United States.

Human papillomavirus (HPV) causes anal, penile and oropharyngeal cancers in men. Genital HPV prevalence in men appears to vary by world region with men residing in Asia having among the lowest prevalence. Unfortunately, there is little information on prevalence of HPV infection in men by race. The purpose of this study was to examine HPV prevalence by race across three countries. 3,909 men ages 18-70 years enrolled in an ongoing prospective cohort study of the natural history of HPV in men (The HIM Study) were included in the analysis. Participants completed risk factor questionnaires and samples were taken from the penile epithelium and scrotum for HPV detection. HPV testing of the combined DNA extract was conducted using PCR and genotyping. Asian/Pacific Islanders had the lowest HPV prevalence of 42.2% compared to Blacks (66.2%), and Whites (71.5%). The Asian/Pacific Islander race was strongly protective in univariate analysis (prevalence ratio (PR) = 0.59; 95% confidence interval (CI): 0.48-0.74) and multivariate analysis for any HPV infection (PR = 0.65; 95% CI: 0.52-0.8). Stratified analysis by lifetime number of female partners also showed strong inverse associations with the Asian/Pacific Islander race. We consistently observed the lowest prevalence of HPV infection among Asian/Pacific Islanders with moderate inverse associations even after various adjustments for potential confounding factors. Unmeasured behavioral factors, sexual mixing with low risk women, and/or race-specific differences in the frequency of germline variations among immune regulating genes may underlie these associations. Further studies among Asian populations that incorporate measures of immuno-genetics are needed to understand this phenomenon.