Understanding sex differences in natural history of anogenital human papillomavirus (HPV) infection is essential for making policies to prevent and control HPV infection and related diseases. However, there is a scarcity of researches focused on both sexes, and direct comparing among different studies is difficult due to different sampling and typing methods.
From May to July 2014, a total of 2309 men and 2378 women aged 18-55 years old were enrolled from communities and universities in Liuzhou, China. Penis / glans penis / coronary sulcus and perianal / anal canal (PA) specimens of men and vaginal, vulvar and PA specimens of women were collected biannually for up to three visits and genotyped for 12 oncogenic HPV (classified as Group 1 by IARC) and 2 non-oncogenic HPV types (HPV 6 and 11) by PCR. Prevalence analysis was performed among 1937 (83.9%) men and 2344 (98.6%) women with the valid HPV typing result at baseline. Totally 1643 (71.2%) men and 1752 (73.3%) women with a median follow-up of 12.5 months (range 5.0-19.1) and 12.6 months (range 5.0-20.1), respectively, were included in incidence analysis.
The prevalence of oncogenic HPV type was higher in women than that in men (18.7% vs 9.4%, P < .001), whereas the prevalence of HPV 6 and 11 infection was similar (1.4% vs 1.2%, P = .6832). Incidences of oncogenic HPV infection in men and women were 10.1 (95% confidence interval (CI) 8.6-11.5) and 9.4 (95% CI 8.2-10.6) per 1000 person-months, respectively, and no sex differences were found (P = .4659). However, men was more likely to acquire HPV 6 or 11 infection than was women (2.0 vs 1.1, P = .0223). Median duration of HPV infection was longer in women than that in men for both oncogenic (11.6 months vs 6.8 months, P < .001) and non-oncogenic (11.9 months vs 6.4 months, P < .001) types. Both prevalence and incidence of oncogenic HPV infection decreased with age in women, but did not vary by age in men. Besides sex behavior, hygiene behavior was also associated with prevalence and incidence of HPV infection in both sexes.
This is the first large population-based prospective study focused on HPV prevalence, incidence and clearance in anogenital sites of both sexes. For oncogenic HPV, though newly acquired anogenital infections were comparable between men and women, the median duration of infection was shorter in men, thus women were more of a major reservoir than men. For HPV types 6 and 11, men had a higher speed to both acquire and clear infection, thus the two sexes seem to contribute similarly to the virus circulation. Our study indicated that interaction of host and virus might be different for oncogenic and non-oncogenic HPV types between sexes.