Sex Differences in the Incidence and Clearance of Anogenital Human Papillomavirus Infection in Liuzhou, China: An Observational Cohort Study

BACKGROUND: Human papillomavirus (HPV) causes anogenital warts and cancers in men and women. However, little is known about sex differences regarding the natural history of anogenital HPV infection. METHODS: Starting in May 2014, an observational cohort study including 2309 men and 2378 women aged 18-55 years was conducted in Liuzhou, China. Samples from anogenital sites were tested for HPV genotypes by multicolor real-time polymerase chain reaction and melting curve analysis biannually for ~1 year. RESULTS: The incidence of oncogenic HPV infection was similar in men and women (10.3 and 11.5/1000 person-months; P = .275), whereas the incidence of HPV-6/11 infection was higher in men than in women (2.0 vs 1.1; P = .018). The incidence of both oncogenic HPV and HPV-6/11 infections was significantly higher in women in the 18- to 25-year age group than in the older age groups (P = .006 and .011, respectively), whereas it did not vary by age among men (P = .552 and .425, respectively). Additionally, men were more likely than women to clear oncogenic infections (101.5 vs 58.6/1000 person-months; P .05). CONCLUSIONS: The natural history of oncogenic and nononcogenic HPV infection differs by sex, which implies that sex-specific vaccination strategies should be considered for oncogenic and nononcogenic HPV. CLINICAL TRIALS REGISTRATION: NCT02188004.