Demographic characteristics associated with genital HPV infection included age, race/ethnicity, marital status, education, and age at first sex. The prevalence of genital HPV was found to be highest among non-Hispanic black men (65.0%) and lowest in non-Hispanic Asian men (24.4%). Men who reported never having been married, living with a partner, or separated from a spouse were twice as likely to have overall genital HPV infections than married men. In the HR HPV group, this prevalence increased to 2.8 times if separated from a spouse. In addition, current tobacco use was not associated with male genital HPV infection, whereas tobacco use is a known risk factor for female genital and oropharyngeal infections.8
The overall genital HPV prevalence in men8 is similar to Denmark data (41.8%), with the same HR HPV type 51 being the most prevalent type.13 In comparison, HR HPV types 16 and 18 are responsible for 79% of all anogenital cancer in men.14 This inconsistency of the most prevalent HR HPV subtype in infection and in cancer may reflect a difference in aggressiveness of HPV subtype. Furthermore, the most prevalent HPV subtype may not reflect putative potency of carcinogenesis. This high burden of genital HPV prevalence in men has been reported in the past. The multinational HPV Infection in Men cohort study previously reported HPV prevalence of 65.2%,15 which is higher than overall HPV prevalence in U.S. men (45.2%).
The difference in prevalence may also be due to the types of test used, the location of the male genital area swabbed, and/or the study population. Nevertheless, other study populations were heavily concentrated in the younger age groups with under-representation of men above age 40.13,15 Perhaps the cumulative high prevalence of chronic, persistent infections would be expected to increase as it was shown in oral HPV infection secondary to decreased immune response to natural infection in aging men.
Clearance of genital HPV infection in men has been reported to be between 6 to 18 months, which is comparable to women.16 However, men have lower circulating HPV antibodies than women despite higher HPV infection prevalence.17 This phenomenon may explain the difference in the HPV immune responses between genders, which may reflect persistent or reactivation of HPV infection in later years of age. In addition, a multinational cohort study reported that the number of partners and new partners in the last 3 months was similar for all age groups. Thus, this behavioral pattern may potentially provide continued HPV exposure throughout life in men.15 Therefore, vaccination programs for older men might be warranted, if men generate a lower and weaker HPV immune response in the setting of remaining at high risk of acquiring new HPV infections throughout their lives.