Prevalence of oral human papillomavirus infection among the general adult population in Hong Kong.

A cross-sectional study in 2021-23 collected oral rinse gargle samples from an human papillomaviruses (HPV) vaccine-naïve general adult population in Hong Kong. HPV was detected by a PCR using SPF10 primers, and genotyped by a linear array covering 25 genotypes. Epidemiologic information including sociodemographics, medical history, oral health, and sexual behavior were collected by a self-administered questionnaire. Altogether, 2323 subjects aged 18-75 (median 47) years with 50.1% male were recruited. The prevalence for oral HPV infection with all genotypes combined, high-risk, and low-risk genotypes was 1.5%, 0.7%, and 0.7%, respectively; and with no statistically significant difference between participant gender. The prevalence increased with age and was highest in women at 45-54 years (2.7% for all genotypes combined), and highest in men aged >64 years (4.1% for all genotypes combined). HPV52 was the most common genotype among all participants. Univariate analysis suggested more lifetime sexual or oral sexual partners as risk factors, but they did not reach statistical significance upon multivariate analysis; whereas higher educational level had an independent protective effect. To conclude, oral HPV prevalence increased with age in Hong Kong. Strategies to prevent oral HPV infection and the associated cancers are urgently needed.

Changes in the Incidence and Human Papillomavirus-Positive Portion of Oropharyngeal Squamous Cell Carcinoma in Hong Kong.

The incidence of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is rising in the West, but little is known in Asia. This study elucidated changes in the incidence and HPV-positive portion of OPSCC in Hong Kong. Data from population-based cancer registry were used to analyze the incidence of OPSCC in association with other head and neck cancers. Archived tumor tissues were tested for HPV. From 1986 to 2020, there was a marked decrease in the incidence of nasopharyngeal and laryngeal cancers, but a persistent increase in OPSCC from 36 cases in 1986 to 116 cases in 2020. The average positive rate for high-risk HPV was 36.1% (112/310) among OPSCC diagnosed in 2010-2020. The HPV-positive rate in recent years was significantly higher than earlier cases (tonsil SCC: 64.7% (55/85) in 2016-2020 vs. 40.4% (19/47) in 2010-2015, p = 0.007). Patients with HPV-positive tonsil cancers were significantly younger than those negative (mean [SD]: 58.9 [9.9] vs. 64.3 [13.3] years, p = 0.006), but no significant difference was observed between genders. A persistent increase in the incidence of oropharyngeal cancer over the last few decades was observed in Hong Kong, which can be explained by the remarkable increase in HPV-positive tonsil cancers.

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 ß/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 ß/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 ß/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 ß/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.

Prevalence and Epidemiologic Profile of Oral Infection with Alpha, Beta, and Gamma Papillomaviruses in an Asian Chinese Population.

Background: Knowledge of the prevalence of and risk factors for oral human papillomavirus (HPV) infection, especially cutaneous types, is limited. Methods: A population-based study using next-generation sequencing consecutively recruited asymptomatic individuals aged 18-64 years from a proportional sampling of the general population of Hong Kong, according to age groups, gender, and regions of residence. We examined associations of alpha-, beta-, and gamma-HPVs from oral rinse samples with participants' sociodemographics by logistic regression models. Results: The prevalence of oral HPV infection among 1426 ethnic Chinese was 15.5% (95% confidence interval [CI], 13.7%-17.5%), 2.5% (95% CI, 1.8%-3.5%), 11.9% (95% CI, 10.3%-13.6%), and 2.9% (95% CI, 2.1%-3.9%) for any type, alpha-, beta-, and gamma-HPV, respectively. Prevalence of any high-risk HPV was 0.8% (95% CI, 0.4%-1.4%), and that of HPV-16 was 0.4% (95% CI, 0.2%-0.8%). HPV-8 and HPV-98 were the most common beta types detected, while HPV-4 and HPV-SD2R were the most common gamma types. Prevalence of alpha- and beta/gamma-HPV infection showed a similar pattern of increase with age, and was higher in men than women. Smoking, drinking, oral sex, and more sexual partners were associated with alpha-HPV. Teeth brushing before sleep was protective for beta/gamma-HPVs. Discussion: The epidemiologic factors associated with oral infection with alpha-HPVs are different from those of beta/gamma-HPVs, suggesting different modes of acquisition and persistence.

Human papillomaviruses and the specificity of PDZ domain targeting.

The human papillomavirus (HPV) E6 oncoprotein is fundamental to the ability of these viruses to induce human malignancy. A defining characteristic of the HPV E6 oncoproteins found in cancer-causing HPV types is the presence of a PDZ binding motif at their extreme C-terminus. Through this motif, E6 is able to interact with a large number of cellular proteins that contain PDZ domains. Many of these cellular proteins are involved in regulation of processes associated with the control of cell attachment, cell proliferation, cell polarity and cell signaling. How E6 targets multiple proteins containing the same recognition domain is still an open question. In this review, we highlight aspects of E6 function and biology that help to answer this question, and thereby provide insight into the role of these substrates during development of HPV-induced malignancy.