Association between self-reported periodontitis and high-risk oral human papillomavirus infection among Indigenous South Australians: A cross-sectional study
Authors: Ali Anna , Rumbold Alice R. , Kapellas Kostas , Lassi Zohra S. , Hedges Joanne , Jamieson Lisa 
Published: March 2022

Introduction
The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing globally, reflecting an increase in human papillomavirus (HPV)-related lesions. Indigenous populations are disproportionately affected by OPSCCs. Currently, testing for oral HPV is not recommended as a screening tool to permit early detection of OPSCCs due to the high population prevalence of HPV infection. Periodontitis may be a marker of oral HPV infection, but previous research evaluating this association has been inconclusive. Here we report a large population-based study examining the association between high-risk oral HPV infection and periodontitis among Indigenous South Australians.

Methods
We utilised a large convenience sample of Indigenous South Australians aged 18+ years recruited between February 2018 and February 2020. Of the original cohort (n = 1011), 748 (73.9%) participants participated in the 12 month follow-up. Detailed information on sociodemographic characteristics, health-related behaviours, and sexual history were collected at enrolment. Saliva samples were collected at 12 months and tested for the presence of oral HPV DNA using the optimized general primer (GP) + PCR system. The primary outcomes were the prevalence of any high-risk oral HPV DNA, and separately, HPV 16 and/or 18. Periodontitis was assessed at follow-up by using validated self-reported periodontitis screening questions. Logistic regression analyses were undertaken to assess the association between self-reported periodontitis and oral HPV infection with adjustment for potential sociodemographic and behavioural confounders, with estimates presented as odds ratios (OR) and 95% confidence interval (CI).

Results
Data on 673 participants (89.9% of the follow-up cohort) were available. Participants ranged in age from 18 to 80 (mean age 42.2, SD 14.7) and 31.5% were male. Overall, 115 (17.1%) participants had self-reported periodontitis, 40 (5.9%) had any high-risk oral HPV and 14 (2.1%) had HPV 16 and/or 18. Any high-risk HPV was detected among seven (17.5%) participants and HPV 16 and/or 18 was detected in three (21.4%) who self-reported periodontitis. In the regression analyses no significant association was found between self-reported periodontitis and high-risk oral HPV (adjusted OR: 1.10; 95% CI: 0.45–2.70) or HPV 16 and/or 18 (adjusted OR: 1.27; 95% CI: 0.32–5.03).

Conclusion
This study did not find any association between self-reported periodontitis and high-risk oral HPV among Indigenous South Australians. Further targeted studies with standardized clinical measures of periodontal disease are needed to clarify the link between high-risk oral HPV and periodontal disease. If confirmed this would add further weight to the importance of recommendations about the utility of periodontitis screening to identify individuals at risk of carrying high-risk oral HPV, who may benefit from more intensive screening and ongoing monitoring.