The results suggest that the periodontal pocket might serve as a reservoir of HPVs in oral mucosa. While having important implications in understanding the HPV transmission, this observation does not rule out the possibility that HPV may be involved in the initiation of periodontal disease.

BackgroundHuman papillomavirus (HPV) infections have been linked to a subset of oral and oropharyngeal cancers. However, little is known on the natural history of oral HPV infections. We designed the prospective Finnish HPV Family Study to assess the dynamics of HPV infections in parents and their infants. This study reports HPV genotype distribution and virus persistence in oral mucosa of the mothers.Materials and MethodsTotally, 324 pregnant women were enrolled at the 3rd trimester of pregnancy and followed-up for 6 years. Oral scrapings taken with a brush were collected and HPV-genotyping was performed with nested PCR and Multimetrix® test (Progen, Heidelberg, Germany). The predictors of persistent oral HPV species 7/9 infections were analyzed using generalized estimating equation models.ResultsThe point prevalence of oral HPV varied from 15% to 24% during the 6-year follow-up. Altogether, 18 HPV genotypes were identified either as single or multiple-type oral infections. HPV16 was the most prevalent type at 9.7%–18.4%, followed by HPV18, HPV6, and multiple infections. Altogether, 74 women had persistent oral HPV infection determined as at least two consecutive samples positive with the same HPV genotype. HPV16 and HPV6 were the two most frequent types to persist (76% and 9%) for a mean of 18.6 and 20.2 months, respectively, followed by multiple infections (8%) for 18.3 months. An increased risk for persistent oral HPV infection with species 7/9 was associated with being seropositive for low-risk (LR)-HPV-types at baseline, whereas the use of oral contraceptives and a second pregnancy during follow-up were protective. Clinical oral lesions were detected in 17% of these women, one-third of whom had persistent oral HPV-infections.ConclusionHPV16 and HPV6 were the most common genotypes in oral HPV-infections and were also most likely to persist. Use of oral contraceptives and a second pregnancy protected against oral HPV persistence.

Persistent high-risk human papillomavirus (HR-HPV) infection is the key event in the progression of HPV lesions, and more data are urgently needed on asymptomatic oral HPV infections in men. Asymptomatic fathers-to-be (n = 131, mean age 28.9 years) were enrolled in the cohort, sampled by serial oral scrapings at baseline and at 2-month, 6-month, 12-month, 24-month, 36-month, and 7-year follow-up visits to accomplish persistent and cleared HPV infections. HPV genotyping was performed using nested PCR and Multimetrix® assay. Covariates of persistent and cleared oral HPV infections were analysed using generalised estimating equation (GEE) and Poisson regression. Altogether, 17 HPV genotypes were detected in male oral mucosa point prevalence, varying from 15.1 % to 31.1 %. Genotype-specific HPV persistence was detected in 18/129 men the mean persistence time ranging from 6.0 to 30.7 months. History of genital warts decreased (p = 0.0001; OR = 0.41, 95 % CI 0.33-0.51) and smoking increased (p = 0.033, OR = 1.92, 95 % CI 1.05-3.50) the risk of persistent species 7/9 HPV infections. Of the 74 HPV-positive men, 71.6 % cleared their infection actuarial and crude clearance times, varying between 1.4 and 79.6 months. No independent predictors were identified for species 7/9 clearance. At the last follow-up-visit, 50.1 % of the fathers had oral mucosal changes, correlating only with smoking (p = 0.046). To conclude, most of the persisting oral infections in males were caused by HPV16. Smoking increased while previous genital warts decreased oral HR-HPV persistence. No predictors of HR-HPV clearance were disclosed.

BackgroundThere are no previous longitudinal studies on genotype-specific natural history of human papillomavirus (HPV) infections in oral mucosa of women.MethodsIn the Finnish Family HPV Study, 329 pregnant women were enrolled and followed up. HPV-genotyping of oral scrapings was performed with nested PCR and Multimetrix® test (Progen, Heidelberg, Germany). Incidence and clearance times and rates for each HPV-genotype identified in oral mucosa were determined. Predictors for incident and cleared HPV infections for species 7/9 genotypes were analyzed using Poisson regression model.ResultsAltogether, 115 baseline HPV-negative women acquired incident oral HPV infection, and 79 women cleared their infection. HPV16 and multiple HPVs most frequently caused incident infections (65% and 12%) in 13.3 and 17.1 months respectively, followed by HPV58, HPV18 and HPV6 (close to 5% each) in 11–24 months. HPV58, HPV18 and HPV66 were the most common to clear. HPV6 and HPV11 had the shortest clearance times, 4.6 months and 2.5 months, and the highest clearance rates, 225.5/1000 wmr and 400/1000 wmr, respectively. The protective factors for incident oral HPV-species 7/9 infections were 1) new pregnancy during follow-up and 2) having the same sexual partner during FU. Increased clearance was related with older age and a history of atopic reactions, whereas previous sexually transmitted disease and new pregnancy were associated with decreased clearance.ConclusionsHPV16 was the most frequent genotype to cause an incident oral HPV-infection. Low risk HPV genotypes cleared from oral mucosa more quickly than high risk HPV genotypes. Pregnancy affected the outcome of oral HPV infection.