Exploring the Impact of Oral Health and Vaccination on Pneumonia-causing Bacteria: Insights from Predictive Modeling

Abstract Nursing home acquired pneumonia (NHAP) is a leading cause of mortality in long-term care facilities (LTCFs). The primary mechanism of infection in older individuals is macro-aspiration of opportunistic pathogens colonizing the oral and nasal cavities. Pneumococcal vaccination is the primary preventative measure, but oral hygiene is increasingly explored as a strategy for reducing oral colonization. While promising, oral health interventions have shown mixed results, likely due to variation in the way that different NHAP-associated pathogens respond to these interventions. To test this, we analyzed oral health survey responses, pneumococcal vaccination status, and longitudinal colonization to identify factors linked to carriage of each pathogen. We found that oral hygiene impacted carriage of bacteria which more frequently colonized the oral cavity (Haemophilus influenzae and Streptococcus pneumoniae), but had limited effect on bacteria that were more prevalent in the anterior nares (Staphylococcus aureus and Pseudomonas aeruginosa). Pneumococcal vaccination reduced oral colonization by both S. pneumoniae and H. influenzae, suggesting community level interactions. Our results suggest that oral hygiene interventions are likely to only be effective against pathogens that primarily colonize the oral cavity, underscoring the importance of identifying the primary reservoirs of NHAP-associated pathogens when developing effective intervention strategies. Competing Interest Statement The authors have declared no competing interest. Funding Statement Collection of oral health data was funded by the Jean Schuler Mini-grant (ST) through the Office of Undergraduate Research and Creative Activities at Northern Arizona University. Sample collection and testing was supported by the Centers for Disease Control and Prevention (contract 75D30121C11191 - TP) and the National Institutes of Health (NIH) National Institute on Minority Health and Health Disparities (U54MD012388 - TP) and National Institute of Allergy and Infectious Diseases (R15AI156771 - TP). The funding agencies had no role in the study design, data collection, analysis, decision to publish, or preparation of the manuscript. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Approval for this project was granted by the Northern Arizona University Institutional Review Board (# 1766728) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability Anonymized data that support the findings of this study are included as supporting information.