Study Reveals COVID-19 Pathway From the Oral Cavity to Lungs

Compared to other risk factors, periodontal diseases and poor oral hygiene may be more accurate predictors of COVID-19 severity, a new study has found. Research conducted by an international team indicates the oral cavity and nose are central entry points for the virus. Published in the Journal of Oral Medicine and Dental Research, the paper, “The COVID-19 Pathway: A Proposed Oral-Vascular-Pulmonary Route of SARS-CoV-2 Infection and the Importance of Oral Healthcare Measures,” suggests effective oral hygiene can reduce the risk of transmission from the oral cavity to the lungs. The authors note that high concentrations of SARS-CoV-2 in saliva, along with periodontal diseases, are associated with an increased risk of death from COVID-19. Consequently, the team explored the oral cavity-COVID-19 connection, outlining the route taken by the virus as it moves through saliva,  into the blood vessels of the neck and chest, through the heart, and to blood vessels in the lungs.

Pointing to evidence that indicates blood vessels of the lungs, rather than airways, are initially affected in COVID-19 disease, the researchers conclude the virus reaches the lungs through blood vessels as the airways do not appear inflamed in computed tomography scans, while the blood vessels look abnormal.

Given the oral cavity connection, the team proposes that oral biofilm accumulation and periodontal inflammation increase the likelihood of SARS-CoV-2 reaching the lungs, possibly resulting in more severe infections. As such, the authors say efforts to improve oral health may help mitigate COVID-19 severity.

From Dimensions of Dental Hygiene. June 2021;19(6):11.