Incidence and clearance of oral human papillomavirus infection: A population-based cohort study in rural China

Natural History of Oral HPV Infection among Indigenous South Australians

This study aims to describe the natural history of and identify the risk factors associated with oral human papillomavirus (HPV) infections in an Australian Indigenous cohort. A longitudinal cohort study design, with baseline (2018), 12-month, and 24-month data obtained from Indigenous Australians aged 18+ years in South Australia, was performed. Face-to-face interviews were conducted, and saliva samples for HPV testing were collected at each time point. Basic descriptive analyses were conducted to calculate prevalence, incidence, persistence, clearance, and incidence proportions of any HPV infection. Multivariable logistic regression analyses with adjusted prevalence ratios (PRs) were conducted to identify risk factors associated with oral HPV infection. Among 993 participants with valid saliva samples, 44 HPV types were identified. The prevalence of infection with any oral HPV infection was 51.3%, high-risk HPV was 11%, and types implicated in Heck's disease (HPV 13 or 32) was 37.4%. The incidence, persistence, and clearance of any and high-risk HPV infections were 30.7%, 11.8% and 33.3% vs. 9.3%, 2.8%, and 9%, respectively. Our findings indicate that the prevalence, incidence, and persistence of oral HPV infection in a large sample of Indigenous Australians were high, and clearance was low. Oral sex behaviours and recreational drug use were risk factors associated with incident high-risk HPV infection.

Estimating the prevalence of non-cervical human papillomavirus infection in mainland China (PROGRESS-Plus): protocol of a national cross-sectional study

INTRODUCTION

Human papillomavirus (HPV) infection is the most common sexually transmissible infection worldwide. Although the prevalence of cervical HPV infection has been extensively reported in women worldwide, few epidemiological studies have examined the prevalence of non-cervical HPV infection among both women and men, especially in China.

METHODS AND ANALYSIS

PROGRESS-Plus is a national, multisite, cross-sectional study that aims to estimate the prevalence of non-cervical HPV infection in women and men aged 18-60 years residing in mainland China. More specifically, PROGRESS-Plus will estimate the prevalence rate of HPV DNA in oral samples from both women and men, and that of anogenital samples from men. The secondary study objectives are to (1) report the aforementioned prevalence rates by HPV genotype, age and geographical region, (2) examine the concordance (ie, prevalence of the same HPV genotype) between the oral and anogenital samples among men, (3) explore risk factors associated with oral (in both women and men) and anogenital (in men only) HPV infection and (4) describe study participants' health-related quality of life, health behaviour, sexual behaviour and health status.

ETHICS AND DISSEMINATION

The study protocol and all required documents have been submitted for review and approval to the Independent Ethics Committees of all the participating sites. All participants will provide their written informed consent on study entry, and all the recorded data will be treated as confidential.

Transmission and clearance of human papillomavirus infection in the oral cavity and its role in oropharyngeal carcinoma - A review

The majority of sexually active individuals becomes infected with human papillomavirus (HPV) at least once in their lifetime. Pathways for HPV transmission vary across different mucosal sites per individual. They include autoinoculation within one host, direct transmission between individuals (including perinatal transmission and transmission during sexual activity), and indirect transmission through contact with hands. The authors aim to clarify the prevalence and route of transmission per anatomic site, inter- and intra-individually, using a narrative review of the literature. In conclusion, transmission of HPV to the oral cavity and oropharynx is hypothesised to occur mainly through sexual contact. Transmission of particles through saliva has not been proven and daily living activities are not a documented source of HPV infection. Oropharyngeal HPV related cancer survivors and their partners do not show increased risk of infection during sexual intercourse. Transmission of HPV to the oral cavity (autoinoculation with fingers or transmission through saliva in deep kissing) is probably of limited importance.

Incidence, Persistence, and Clearance of Anal Human Papillomavirus among Men Who Have Sex with Men in China: An Observational Cohort Study

(1) Background: We conducted a prospective observational cohort study to measure incidence, persistence, and clearance of anal human papillomavirus (HPV) among men who have sex with men (MSM) in China. (2) Methods: MSM were recruited in Guangzhou, Shenzhen and Wuxi, China in 2017. A tablet-based questionnaire was used to collect sociodemographic and behavioral characteristics. An anal brush sample was collected for HPV testing and genotyping. Participants were followed up 12 months after enrolment. (3) Results: A total of 196 participants completed two HPV tests with a median age of 27.3 (interquartile range (IQR) 24.0–32.8) years. Rate of incidence, persistence, and clearance for HPV among MSM were 31.3 (95% confidence interval (CI) 24.7–39.2), 47.9 (36.8–61.3), and 122.5 (104.3–143.0) per 1000 person months (pm), respectively. HPV 16 (4.1/1000 pm) had the highest incidence rate, and HPV 6 (47.4/1000 pm) had the highest persistence rate. Having lower education and engaging in receptive anal intercourse were potential risk factors of HPV incidence. A higher incidence rate was observed among younger MSM. (4) Conclusions: The high incidence and low clearance of anal HPV highlight the necessity of HPV vaccination among MSM. Further studies are needed to clarify the HPV dynamics at multiple anatomical sites and the burden of HPV-related diseases among MSM.

Salivary High-Risk Human Papillomavirus DNA as a Biomarker for Human Papillomavirus-Driven Head and Neck Cancers

High-risk human papillomavirus (HR-HPV) infection is a major risk factor of head and neck cancers (HNCs). Despite the rising prevalence of HPV-driven HNC (HPV-HNC), biomarkers for detection, prognostication, and disease monitoring are lacking. To evaluate the capacity of salivary HR-HPV DNA as a biomarker of HPV-HNC, the salivary HR-HPV statuses of 491 and 10 patients with primary and recurrent HNC, respectively, were determined at diagnosis, using quantitative real-time PCR, with tumor cyclin-dependent kinase inhibitor 2A (p16) expression determined by IHC analysis. Patients with oropharyngeal cancer (OPC) (n = 215) were followed up for ≤5 years. Survival characteristics were evaluated in terms of event-free and cause-specific survival. Of the primary-HNC cohort, 43.2% were positive for salivary HR-HPV DNA, with most having OPC. Salivary HR-HPV DNA was detected in 81.4% of tumor p16-positive OPC patients at diagnosis. Prognosis in salivary HR-HPV-positive OPC patients was favorable compared with that in salivary HR-HPV-negative patients (event-free survival, hazard ratio = 0.42 [95% CI, 0.21-0.81, P = 0.010]; cause-specific survival, hazard ratio = 0.39 [95% CI, 0.18-0.86, P = 0.019]). In the recurrent-HNC cohort, salivary HR-HPV DNA was detected in 83.3% of those who previously had tumor p16-positive HNC. These findings indicate that this liquid biopsy-based, noninvasive biomarker could be essential in the detection and management of HPV-HNC.

Oral microbiome and risk of malignant esophageal lesions in a high-risk area of China: A nested case-control study

Objective

We aimed to prospectively evaluate the association of oral microbiome with malignant esophageal lesions and its predictive potential as a biomarker of risk.

Methods

We conducted a case-control study nested within a population-based cohort with up to 8 visits of oral swab collection for each subject over an 11-year period in a high-risk area for esophageal cancer in China. The oral microbiome was evaluated with 16S ribosomal RNA (rRNA) gene sequencing in 428 pre-diagnostic oral specimens from 84 cases with esophageal lesions of severe squamous dysplasia and above (SDA) and 168 matched healthy controls. DESeq analysis was performed to identify taxa of differential abundance. Differential oral species together with subject characteristics were evaluated for their potential in predicting SDA risk by constructing conditional logistic regression models.

Results

A total of 125 taxa including 37 named species showed significantly different abundance between SDA cases and controls (all P<0.05 & false discovery rate-adjusted Q<0.10). A multivariate logistic model including 11 SDA lesion-related species and family history of esophageal cancer provided an area under the receiver operating characteristic curve (AUC) of 0.89 (95% CI, 0.84−0.93). Cross-validation and sensitivity analysis, excluding cases diagnosed within 1 year of collection of the baseline specimen and their matched controls, or restriction to screen-endoscopic-detected or clinically diagnosed case-control triads, or using only bacterial data measured at the baseline, yielded AUCs>0.84.

Conclusions

The oral microbiome may play an etiological and predictive role in esophageal cancer, and it holds promise as a non-invasive early warning biomarker for risk stratification for esophageal cancer screening programs.

Natural history of oral HPV infection: Longitudinal analyses in prospective cohorts from Australia

Oral infection with human papillomavirus (HPV) is likely to underpin the rapidly rising incidence of oropharyngeal squamous cell carcinoma; however, there are few data describing the natural history of oral HPV infection. We recruited 704 participants aged 20 to 70 years from worksites, universities and primary care practices in Brisbane, Australia. Participants completed questionnaires at baseline, 12 and 24 months and donate four saliva samples at baseline, 6, 12 and 24 months for HPV polymerase chain reaction testing and typing. We estimated the prevalence of oral HPV infection at baseline, incidence of new infections among those HPV-negative at baseline, clearance rate and persistent infections. At baseline, 10.7% of participants had oral HPV infections from 26 different HPV types. Sexual behaviours were associated with oral HPV infection, including more partners for passionate kissing (29 or more; odds ratio [OR] 3.4, 95% confidence interval [CI] 1.5-8.0), and giving and receiving oral sex (16 or more; OR 5.4, 95% CI 1.6-17.7 and OR 5.6, 95% CI 1.6-18.7, respectively). Of 343 participants, HPV-free at baseline and with subsequent saliva samples, 87 (25%) acquired new infections over the 24 months. Sixty-eight of 87 people included in the clearance analysis (78%) cleared their oral HPV infections. Clearance was associated with being a nonsmoker (OR 12.7, 95% CI 1.3-122.8), and no previous diagnosis of a sexually transmitted infection (OR 6.2, 95% CI 2.0-19.9). New oral infections with HPV in this sample were not rare. Although most infections were cleared, clearance was not universal suggesting a reservoir of infection exists that might predispose to oropharyngeal carcinogenesis.

Persistence and clearance of oral human papillomavirus infections: A prospective population-based cohort study

OBJECTIVE

This study aimed to evaluate the incidence of and factors associated with persistence and clearance of oral human papillomavirus (HPV) infections.

METHOD

A prospective cohort study invited 458 subjects (231 HPV-positive and 227 HPV-negative at baseline) to attend follow-ups at 12 months. Those 231 HPV-positive subjects and 10 new infections were invited to reassessment at 24 months. We used next-gen sequencing for detection and genotyping of HPV.

RESULTS

α-HPV infections showed higher persistence rates than β/γ-HPV (22.7% vs 9.2% at 12 months [P < .05], 10.6% vs 6.8% at 24 months [P = .30]). Clearance rates of α-HPV were lower than β/γ-HPV at 12 months (31.8% vs 45.1%; P = .05) and higher at 24 months (7.6% vs 4.8%; P = .36). Persistence of β/γ-HPV was positively associated with males (crude odds ratio [COR] = 3.8, 95% confidence interval [CI] = 1.3-11.2), elderly (51-65 vs 16-50 years; COR = 5.1, 95% CI = 1.2-22.3), and smoking (COR = 4.3, 95% CI = 1.9-9.6). Drinking (COR = 0.5, 95% CI = 0.3-0.9), handwashing less than 90% of times before meals (COR = 0.6, 95% CI = 0.3-0.9), and using public bath more than once per month (COR = 0.5, 95% CI = 0.2-0.9) were risk factors hindering β/γ-HPV clearance.

CONCLUSIONS

This study identified factors associated with persistence and clearance of oral HPV infections among Chinese. Studies on other ethnogeographic groups may further inform prevention strategies of oral HPV infection and immunization programmes.

Oral Infection by Mucosal and Cutaneous Human Papillomaviruses in the Men Who Have Sex with Men from the OHMAR Study

Both mucosal and cutaneous Human Papillomaviruses (HPVs) can be detected in the oral cavity, but investigations regarding the epidemiology of cutaneous HPVs at this site are scarce. We assessed mucosal (alpha) and cutaneous (beta and gamma) HPV infection in oral samples of HIV-infected and uninfected men who have sex with men (MSM). Oral rinse-and-gargles were collected from 310 MSM. Alpha HPVs were detected using the Linear Array, whereas beta and gamma HPVs were detected using multiplex PCR and Luminex technology. An amplicon-based next-generation sequencing (NGS) protocol was applied to a subset of samples collected from 30 HIV-uninfected and 30 HIV-infected MSM. Beta HPVs were significantly more common than alpha types (53.8% vs. 23.9% for HIV-infected subjects, p < 0.0001; 50.3% vs. 17.1% for HIV-uninfected subjects, p < 0.0001). Gamma HPVs were also frequently detected (30.8% and 25.9% in HIV-infected and uninfected MSM, respectively). NGS produced 2,620,725 reads representative of 146 known HPVs (16 alpha-PVs, 53 beta-PVs, 76 gamma-PVs, one unclassified) and eight putative new HPVs, taxonomically assigned to the beta genus. The oral cavity contains a wide spectrum of HPVs, with beta types representing the predominant genus. The prevalence of beta and gamma HPVs is high even in immunorestored HIV-infected individuals. NGS confirmed the abundance of cutaneous HPVs and identified some putative novel beta HPVs. This study confirms that cutaneous HPVs are frequently present at mucosal sites and highlights that their pathological role deserves further investigation since it may not be limited to skin lesions.

Oral human papillomavirus infection in HIV-infected and HIV-uninfected MSM: the OHMAR prospective cohort study

OBJECTIVE

We aimed to assess incidence and clearance of oral human papillomavirus (HPV) infection and the respective risk factors in HIV-infected and uninfected men who have sex with men (MSM).

METHODS

Oral rinse and gargles were collected semiannually from 244 MSM (103, 42.2% HIV-infected). HPV-DNA testing was performed with the Linear Array HPV Genotyping test. A Markov model was used for estimation of incidence, clearance and risk factor analysis.

RESULTS

Incidence rates for any HPV were 21.2 and 15.0×1000 person-months in HIV-infected and uninfected MSM, respectively. The respective figures for high-risk HPVs were 10.7 and 6.5×1000 person-months. The clearance rate was 4-12 times higher than the respective incidence rate. HIV-infected MSM with >95 lifetime oral sex partners showed increased incidence of any HPV (adjusted HR, aHR: 8.46, 95% CI 1.89 to 37.92). Condomless oral sex appeared the strongest predictor for incident infection by high-risk HPVs in this group (aHR: 13.40, 95% CI 2.55 to 70.53). Those aged >46 years (aHR: 0.30, 95% CI 0.12 to 0.74) and those with nadir CD4+ T count of <200 cells/mm³ (aHR: 0.14, 95% CI 0.03 to 0.75) displayed a significantly reduced clearance of any and high-risk HPVs, respectively. HIV-uninfected MSM aged >46 years had increased risk of acquiring any HPV (aHR: 3.70, 95% CI 1.30 to 10.52) and high-risk HPV (aHR: 5.33, 95% CI 1.06 to 26.68). Any HPV clearance declined in those with more than six recent oral sex partners (aHR: 0.18, 95% CI 0.05 to 0.65).

CONCLUSIONS

Acquisition of oral HPV infection in MSM seems to occur rarely, whereas clearance seems to be a frequent event. Oral HPV natural history in these at-risk subjects is differently influenced by age and sex behaviour, depending on HIV status.

Estimating incidence rates of grouped HPV types: A systematic review and comparison of the impact of different epidemiological assumptions

BACKGROUND

Some studies on human papillomavirus (HPV) provide not only type-specific incidence rates (IR), but also IRs of HPV groupings (e.g. the nonavalent grouping). We made an inventory of the different approaches used to calculate such IRs and assessed their impact on the estimated IRs of HPV groupings.

METHODS

We performed a systematic review assessing all approaches used in literature to estimate IRs. Subsequently we applied these approaches to data of a Dutch cohort study on HPV in men who have sex with men (H2M). IRs were estimated for six different HPV groupings.

RESULTS

The systematic review yielded six different approaches (A-F) for estimating the IRs, varying in exclusion criteria at baseline, and the definitions of an incident event and person-time. Applying these approaches to the H2M dataset (n = 749), we found differences in the number of participants at risk, number of incidents events, person-time, and IR. For example, for the nonavalent grouping, depending on the approach chosen, the IR varied between 3.09 and 6.54 per 100 person-months.

CONCLUSION

In published studies different epidemiological assumptions are used to estimate IRs of grouped HPV types, leading to widely differing estimates of IRs. IRs between different studies may therefore not be comparable.

Oral manifestations of human papillomavirus infections

Papillomaviruses are one of the oldest viruses known, dating back 330 million years. During this long evolution, human papillomaviruses (HPV) have developed into hijackers of human cellular and immune systems in which they replicate and remain silent. Systematic studies on oral HPV infections and their outcomes are still scarce. Oral HPV infections have been linked to sexual behaviour, but recent evidence supports their horizontal, mouth‐to‐mouth, transmission. Most HPV infections in infants are acquired vertically from the mother during the intrauterine period, during delivery, or later via saliva. The best‐known benign clinical manifestations of HPV infection are oral papilloma/condyloma and focal epithelial hyperplasia. Evidence is emerging which suggests that some oral HPV infections might persist. Persistent HPV infection is mandatory for HPV‐associated malignant transformation. However, progression of HPV‐induced lesions to malignancy requires additional cofactors. In the early 1980s, we provided the first evidence that a subset of oral cancers and other head and neck cancers might be causally linked to HPV infection. This review summarizes current knowledge on the virus itself, its transmission modes, as well as the full spectrum of oral HPV infections – from asymptomatic infections to benign, potentially malignant oral lesions, and squamous cell carcinoma.

Incidence, mortality, and temporal patterns of oropharyngeal cancer in China: a population-based study

Background

Thus far, the incidence, mortality, and temporal trend data of oropharyngeal cancers (OPC) in China were few. We estimated the incidence, mortality, and temporal patterns of OPC in China during 2008–2012 according to the data from 135 population-based cancer registries to better understand the epidemiological pattern of OPC and to provide more precise information for OPC control in China.

Methods

According to the data of diagnosed OPC reported to 135 cancer registries during 2008–2012, we calculated age-standardized rate of incidence and mortality by 2000 Chinese standard population (ASRIC and ASRMC) and by 1985 Segi’s world standard population (ASRIW and ASRMW) by age, sex, and geographic regions; annual percentage changes of OPC incidence and mortality were calculated using Joinpoint trend analysis.

Results

ASRIW and ASRMW were 2.22/100,000 person-years and 0.94/100,000 person-years, respectively. The incidence and mortality in urban areas were higher than those in rural areas. ASRIC and ASRIW of males were higher than those of females. The overall ASRIC of OPC was significantly increased by 6.2% annually between 2003 and 2006 (P = 0.038), but remained stable between 2007 and 2012 (P = 0.392). ASRIC and ASRMC of males and in rural areas were significantly increased in the last decade (P < 0.05), but the rates of females remained stable during the same period (P > 0.05).

Conclusions

Across multiple cancer registries in China, there was an obvious increase in OPC in the recent decade, especially for incidence and mortality of males and in rural areas, whereas the rates of females remained stable. A healthy lifestyle should be advocated and early diagnosis and early treatment of OPC should be enhanced.

Electronic supplementary material

The online version of this article (10.1186/s40880-018-0345-5) contains supplementary material, which is available to authorized users.

Tobacco smoking, alcohol drinking, betel quid chewing, and the risk of head and neck cancer in an East Asian population

BACKGROUND

The smoking prevalence among men in China is high, but the head and neck cancer incidence rates are low. This study's purpose was to investigate the impact of tobacco, betel quid, and alcohol on head and neck cancer risk in East Asia.

METHODS

A multicenter case-control study (921 patients with head and neck cancer and 806 controls) in East Asia was conducted. The odds ratio (OR) and 95% confidence interval (CI) were estimated using logistic regression.

RESULTS

Head and neck cancer risks were elevated for tobacco (OR = 1.58), betel quid (OR = 8.23), and alcohol (OR = 2.29). The total attributable risk of tobacco and/or alcohol was 47.2%. Tobacco/alcohol appeared to account for a small proportion of head and neck cancer among women (attributable risk of 2.2%). Betel quid chewing alone accounted for 28.7% of head and neck cancer.

CONCLUSIONS

Betel quid chewing is the strongest risk factor for oral cavity cancer in this Chinese population. Alcohol may play a larger role for head and neck cancer in this population than in European or U.S.

POPULATIONS

Human papilloma virus: global research architecture assessed by density-equalizing mapping

Human papilloma virus (HPV) infection is linked to cervical cancer, which represents the world's fourth most common cancer in women. So far, no detailed map of the worldwide HPV research architecture has been constructed. Hence, this study focuses on the chronological development and geographical distribution of the global HPV-specific publications and evaluates citation-based parameters as well as socioeconomic features of the publishing countries. In total, 29,330 HPV-related publications were identified. The US was the leading country with 12,270 publications. Only high-income-countries were found in the ranking of the fifteen most active countries with Germany, France, and Japan among the top five. Analysis of HPV research activity in relation to the economic strength demonstrated a lead position of Finland and Sweden with an average of 2248.78 and 1924.67 HPV-related publications per GDP in 1000 bn US-$, respectively. The most active upper-middle-income country was Mexico (416.78 HPV-related publications per GDP in 1000 bn US-$). India as lower-middle-income country reached a value of 279.78 HPV-related publications per GDP in 1000 bn US-$. Collaboration analysis pointed to the US as the center of the 4517 international HPV collaborations. The worldwide HPV-research landscape is dominated by North American and Western European countries. By contrast, a high prevalence of HPV-related cervical cancer is documented for low-income countries. Hence, HPV-related public health interventions and prevention research specifically tailored to these countries needs to be fostered by monetary support and international collaborations.