One health and oral health : the case of SARS-CoV-2

Abstract

Objectives: The concept of ‘One Health’ highlights the interconnectedness of human, animal, and environmental health. The emergence of COVID-19 underscores how ecosystem disruption affects human health. This thesis explored the interconnections between one health and oral health through a scoping review and citation analysis. An umbrella review was undertaken to provide a comprehensive overview of evidence relating to the use of mouthwashes against respiratory pathogens, primarily SARS-CoV-2. Clinical efficacy and satisfaction with the use of Hong Kong government-recommended pre-procedural mouthwashes were evaluated in the dental setting during COVID-19 pandemic. An animal-based study examined the bidirectional link between periodontitis and SARS-CoV-2 infection. Methods: A scoping review, citation analysis and umbrella review were undertaken. The methodological quality of included systematic reviews was assessed using the AMSTAR 2 tool (A MeaSurement Tool to Assess systematic Reviews 2). A triple-blind randomized controlled clinical trial was conducted to evaluate clinical efficacy and satisfaction with government-recommended pre-procedural mouthwash groups (Povidone-iodine 1%, Hydrogen Peroxide 1.5% w/v and Chlorhexidine Digluconate 0.2% w/v). A golden Syrian hamster model investigated the bi-directional relationship between periodontitis and SARS-CoV-2 infection, and immune response. Results: The scoping review identified 345 articles, and 13 ‘effective studies’ informed this review, covering environmental impacts (53.8%, 7/13) and animal health impacts (46.2%, 6/13) on human health/oral health. The citation analysis identified 114 publications related to one health and oral health, mostly since 2010 (85.1%, 97/114), typically in America and Europe (89.5%, 102/114), with limited interconnectedness. The umbrella review identified 28 systematic reviews concerning the effectiveness of mouthwashes against SARS-CoV-2, but mostly of low/very low methodological quality (89.3%, 25) and with conflicting evidence to support their use in practice. The clinical trial involved 228 participants. There was a significant reduction in the prevalence of detected respiratory viral pathogens in their salvia following the use of recommended preprocedural mouthwashes (P < 0.05), but mouthwashes had similar efficacy (P > 0.05). Satisfaction ratings for mouthwashes were high, and with comparable satisfaction ratings among mouthwash groups (P > 0.05) and similar acceptability ratings (P > 0.05). The animal study identified that hamsters with periodontitis developed more severe lung damage following SARS-CoV-2 infection at the acute phase through dysregulated pro-inflammatory mediators induced by primed myeloid cells. Furthermore, acute SARS-CoV-2 infection induced transient periodontal bone loss with increased osteoclastogenic activity. Conclusions: The scoping and citation review identified growing and recent interest in one health in the oral health context. To date, studies are limited in terms of numbers, methodological quality, and global representation. The umbrella review identified many systematic reviews supporting the effectiveness of mouthwashes in mitigating respiratory pathogens, including SARS-CoV-2 but mostly of low/very low methodological quality, and thus the need for cautious interpretation in translating the evidence into clinical practice. Hong Kong government-recommended pre-procedural mouthwashes were effective against respiratory pathogens in the dental setting, and there was high satisfaction and acceptability with their use. The golden Syrian hamster model identified a bi-directional relationship between periodontitis and SARS-CoV-2, highlighting the importance of periodontal health as we adapt to live with COVID-19.

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