Sex Differences in Risk Factors and Natural History of Oral Human Papillomavirus Infection.

UNLABELLED: Oral human papillomavirus genotype 16 (HPV16) infection causes oropharyngeal squamous cell carcinoma (SCC), and the prevalence of oropharyngeal SCC is higher among men than women in the United States. In a cohort study of oral HPV infection among 409 individuals aged 18-25 years, the risk among men but not among women significantly increased as the number of recent (ie, within the prior 3 months) oral sex partners increased (Pinteraction = .05). In contrast, the risk among women but not among men significantly decreased as the lifetime number of vaginal sex partners increased (Pinteraction = .037). Men were also significantly less likely than women to clear oral HPV infection. Our data contribute to understanding sex differences in risk for HPV-positive oropharyngeal SCC. CLINICAL TRIALS REGISTRATION: NCT00994019.

Oral Human Papillomavirus (HPV) Infection among Unvaccinated High-Risk Young Adults.

Oral HPV infection, the cause of most oropharyngeal cancer in the U.S., is not well studied among high-risk young adults. Men (n = 340) and women (n = 270) aged 18-25 years attending Baltimore County STD clinics were recruited if they declined HPV vaccination. Each participant had a 30-second oral rinse and gargle sample tested for 37 types of HPV DNA, and a risk-factor survey. Factors associated with prevalent infection were explored using log binomial regression. Men had higher prevalence of any oral HPV (15.3% vs. 7.8%, p = 0.004) and vaccine-type oral HPV (i.e., HPV16/18/6/11: 5.0% vs. 1.1%, p = 0.007) infection than women. In multivariate analysis, male gender (aPR = 1.93, 95% CI = 1.10-3.39), number of recent oral sex partners (p-trend = 0.013) and having ever performed oral sex on a woman (aPR = 1.73, 95% CI = 1.06-2.82) were associated with increased oral HPV prevalence. Performing oral sex on a woman may confer higher risk of oral HPV acquisition than performing oral sex on a man.