Oral Mucosa as a Reservoir of Human Papillomavirus: Point Prevalence, Genotype Distribution, and Incident Infections Among Males in a 7-year Prospective Study

Abstract

BackgroundIn addition to the anogenital malignancies, human papillomavirus (HPV) has been linked to oropharyngeal cancer as an important risk factor in both men and women. Knowledge of oral HPV infection among males is needed to elucidate the transmission routes and potential for prevention. ObjectiveTo assess the prevalence, genotype distribution, and incidence of oral HPV infections among healthy Finnish men followed for 7 yr. Design, setting, and participantsOral scrapings for HPV testing were taken from 131 fathers-to-be (mean age: 28.9 yr) at baseline and at 2-mo, 6-mo, 12-mo, 24-mo, 36-mo, and 7-yr follow-up visits to detect prevalent and incident HPV infections. Purified DNA extracted from scrapings was used for HPV genotyping, with the Multimetrix kit (Progen Biotechnik, Heidelberg, Germany) detecting 24 genotypes. Outcome measurements and statistical analysisPoint prevalence, genotype distribution, and incident rates of oral HPV infections. Demographic data were collected using structured questionnaires, and covariates of incident oral HPV infections were analysed using uni- and multivariate Poisson regression (for panel data). Results and limitationsThe point prevalence of oral HPV infection fluctuated from 15.1% to 31.1% during the follow-up period. In total, 17 different HPV genotypes were found. At baseline, the single most frequent genotype among the HPV-positive samples was HPV16 (33.3%; 8 of 24), followed by HPV33 (12.5%) and HPV82 (12.5%). Multiple-type infections comprised 16.7% (4 of 24), HPV16 being involved in all combinations. For baseline-negative men, the mean time to the first incident infection ranged from 3.9 mo (HPV82) to 25.7 mo (HPV56). None of the demographic factors was a significant independent predictor of incident oral HPV infections in multivariate models. ConclusionsDetection of oral HPV DNA carriage in men is common, HPV16 being the most prevalent genotype. Oral mucosa may play a significant role in HPV transmission.