Researchers have found that HPV infections are common among young, heterosexual men, but the infections subsequently clear, similar to the HPV course in young women.
“While many of these infections clear, the median time to clearance is likely to be 6 months or longer, making HPV transmission likely,” the researchers wrote in The Journal of Infectious Diseases. “Therefore, male vaccination may reduce the transmission and overall incidence of HPV infections, as well as the rate of HPV-associated diseases among heterosexual men in the community.”
The study included 1,732 men aged 16 to 24 years who were enrolled in the placebo arm of a quadrivalent HPV vaccine trial. Men from 18 countries in Africa, Asia-Pacific, Europe, Latin America and North America were included. All men underwent anogenital exams and provided samples from the penis, scrotum and perineal/perianal regions.
The incidence rate of HPV 6, 11, 16 or 18 among the men, who were seronegative at day 1, was nine per 100 person-years at risk. When stratified by region, South Africa had the highest incidence and Asia-Pacific had the lowest incidence. The rate of HPV detection was highest on penile swabs with a rate of 8.2 per 100 person-years, followed by scrotal swabs and perineal/perianal swabs. HPV 16 was the most common.
The median time to clearance of HPV was 6.1 months for HPV 6 and HPV 11; 7.7 months for HPV 16; and 6.2 months for HPV 18. The risk factors associated with detection of any HPV type included higher number of lifetime sexual partners, lack of condom use and living in South Africa. Smoking and circumcision were not risk factors. Approximately 30% of the men with an HPV 6 or HPV 11 infection were diagnosed with external genital warts. The incidence rate of external genital warts was 0.94 per 100 person-years at risk.
Disclosure: The study was funded by Merck, and some of the researchers have various financial ties with Merck. See the study for a full list of financial disclosures.