Oral HPV infection is common worldwide, but risk of infection differs by sex, continent, population at infection, and year

Summary Subjects or Study Selection: The literature published (in English only) from January 1995 to August 2017 was initially searched for studies on the prevalence, incidence, clearance, and persistence of oral HPV infection among human subjects, using the PubMed, Ovid, Medline, Ovid Embase, and Cochrane Library databases. Sixty-six studies met the inclusion and quality criteria as determined through the full text reviews by 2 independent reviewers. Excluded were case-control studies, studies only with patients or an unhealthy population (e.g., HIV-positive subjects), and systemic reviews and meta-analyses. Key Study Factor The outcome measures, mostly the prevalence of oral HPV infection, were analyzed from cross-sectional studies with heterogenous study populations and compared by sex (male and female), continent (Europe, North America, South America, Africa, Asia, and Oceania), population at infection risk (low and high), study period (prior to 2000, 2000-2009, and 2010-2017), and HPV-type (low-risk and high-risk). The number of studies was insufficient for meta-analyses of the clearance (6 studies) and persistence (5 studies) outcomes. Main Outcome Measure Main outcome measure is oral HPV infection. To understand the natural history and epidemiology of oral HPV infection, meta-analyses were conducted and generated pooled estimates for prevalence (from 63 studies, sample size = 56,600) and incidence (from 8 studies, sample size = 5441). HPV testing in the mouth or throat varied (cotton swab, cytobrush, or mouth rinse with DNA essay), and was not standardized, throughout the study period. Unlike cervical infection, the natural history of oral HPV, from exposure to development of oropharyngeal cancer, is still mostly unknown. Main Results Overall, 7.7% (95% confidence interval [CI], 6.8-8.6) of the study population had an oral infection with any HPV strain; 1.4% (95% CI, 1.0-1.9) had infection with HPV16. Infection was more prevalent among men, among populations at high risk, and, during the recent decades, than counterparts (women, populations at low risk, and prior to 2010). A majority of the studies were conducted in Europe and North America where 9.9% (95% CI, 7.2-12.5) and 7.7% (95% CI, 5.9-9.6) of the population, respectively, were reported to have oral HPV infection (any strain). South America also showed prevalences in a higher range (12.4%, 95% CI,5.7-19.1), and Asia had the lowest estimate (2.6%, 95% CI, 0-6-4.6). Sub-group analyses showed a great variability of the study population characteristics and methodology; therefore it was not possible to provide homogenous estimates in each sub-group. Overall incidence was 4.38/1000 person-months for all HPV type infection (95% CI, 3.25-5.91). Meaningful estimations by sub-group were not possible because of the small numbers among the study population. An insufficient number of the studies were suitable for meta-analyses for clearance and persistence outcomes. Conclusions Oral HPV infection is significantly prevalent and widespread worldwide, particularly among men and among populations at risk. Prevalence has increased during the last two decades.