Exploration of correlation of oral hygiene and condition with influenza infection

Abstract

Influenza viruses are known to be infected through epithelial cells of the upper respiratory tract. The oral cavity is in close anatomical proximity to the upper respiratory tract, and it is conceivable that the viruses could pass through the oral cavity and infect to the upper respiratory tract. Several researchers have suggested that colonization of certain pathogenic bacteria such as Staphylococcus aureus or Streptococcus pneumoniae might affect the risk of influenza viral disease, indicating that oral hygiene and/or condition might play an important role in respiratory viral infection. Therefore, the purpose of this study was to investigate whether an oral hygiene/condition might impact influenza infection. We conducted a retrospective observational study of Japanese citizens’ regional cohort (N = 2,904) consisting of National Health Insurance beneficiaries who underwent annual health/dental examination with data entries in the Kokuho database (KDB). Trained dentists checked the oral hygiene/condition, and saliva specimens were examined using the LION dental saliva multi-test (SMT) kit. Influenza infection was identified from the diagnosis recorded in the KDB. The correlations between influenza infection and oral hygiene, dryness of the mouth, or various salivary test results were examined by a multivariate analysis adjusting for confounding factors such as gender, age, recent smoking, alcohol drinking, BMI, HbA1c, RBC for influenza infection. The logistic regression model showed that age significantly correlated with influenza infection. In addition, oral hygiene status had a nearly significant impact on influenza infection (p = 0.061), whereby, the subjects with poor oral hygiene had a higher risk of influenza infection than those with good oral hygiene (odds ratio: 1.63, 95% confidence interval: 0.89–2.95). Further, the prevalence of influenza infection was lower in the subjects with saliva weakly acidic and/or containing higher protein level. The results of this study suggested that the maintenance of oral health conditions might be one of the pivotal factors for preventing and reducing influenza infection.

Comparison of proteins with anti-influenza virus effects in parotid and submandibular-sublingual saliva in humans

“…Male volunteers were recruited from among the employees of the Kao Corporation in Japan; women were excluded from this study to avoid effects of the menstrual cycle on salivary flow rates [ 18 ]. Only healthy individuals without systemic disorders or metabolic diseases with good oral hygiene [ 19 ] were enrolled. The study protocol was approved by the Ethics Committee of the Kao Corporation (approval number: S201-180918), and followed the tenets of the Declaration of Helsinki.…”

Impacto da condição de saúde bucal no paciente com covid-19 internado em Unidade de Terapia Intensiva

“…No entanto, o mecanismo que envolve a proliferação do vírus e como ele interage com outros microrganismos do corpo humano ainda não está totalmente elucidado 3 . Durante outras pandemias foi possível observar que as infecções virais respiratórias predispõem os pacientes a superinfecções bacterianas, levando ao aumento da gravidade da doença e da mortalidade; como o que houve na pandemia de influenza em 1918 em que foi estimado que 95% das mortes tenham ocorrido devido à pneumonia bacteriana 4 .…”