Human Papillomavirus Infections in Men: Incidence and Clearance

Among HIV-negative men in three countries, the incidence of new genital HPV infection was 38.4 cases per 1000 person-months.

Human papillomavirus (HPV)-related cancers occur in men and women, yet little is known about the natural history of HPV infections in men. Now, investigators have conducted a prospective study to assess the incidence and clearance of HPV among HIV-negative men aged 18 to 70. (One of the investigators receives support from Merck, which produces an HPV vaccine.)

Participants were recruited from the general population, universities, and organized healthcare systems in the U.S., Brazil, and Mexico. Before enrollment and every 6 months thereafter, they underwent swabbing of the penis and scrotum for HPV testing (detection of DNA by polymerase chain reaction; genotyping) and completed a computer-based questionnaire.

Although the full cohort involved 4074 men, most analyses were conducted among the first 1159 who enrolled and completed 2 weeks of follow-up (mean age, 32.1; median follow-up, 27.5 months). The incidence of new genital HPV infection was 38.4/1000 person-months and did not vary with age. Median time to clearance was 7.2 months for oncogenic HPV types and 7.6 months for nononcogenic types. This interval was significantly longer in 18- to 30-year-olds than in older men. In multivariate analysis, oncogenic HPV infection was significantly associated with having a high number of lifetime female sexual partners or recent male anal-sex partners.

Comment: This study shows that HPV infection is common among men. An editorialist notes different natural histories in men and women: The rate of penile intraepithelial neoplasia is 10 to 20 times lower than the rate of cervical intraepithelial neoplasia, even though HPV infection rates are higher in men than in women. Because condoms provide only limited protection against HPV acquisition, the role of vaccination merits study. The present findings provide useful information about HPV acquisition and clearance in men. However, as the authors caution, the study cohort is a select population, so incidence estimates may not be generalizable to men in the three countries evaluated.

— Mary E. Wilson, MD

Published in Journal Watch Infectious Diseases March 9, 2011