SARS-CoV-2 might enter lungs through gingivae, experts say
LEIPZIG, Germany: As the COVID-19 pandemic has progressed, more and more has been discovered about the virus and disease. Previously, it was assumed that SARS-CoV-2 infected the lungs only via the upper airways. Now, another hypothesis has been formally published that suggests that the virus is transmitted via a vascular route from the oral cavity to the lungs.
The research team of scientists from Salisbury District Hospital and the University of Birmingham in the UK and the Mouth-Body Research Institute in Los Angeles in the US and Cape Town in South Africa has proposed that dental plaque accumulation and periodontal inflammation make it more likely that SARS-CoV-2 will reach the lungs from the mouth and cause more severe cases of infection.
Initial observations of lung CT scans of patients suffering from COVID-19 lung disease by consultant radiologist Dr Graham Lloyd-Jones, who is lead author of the hypothesis, led to a collaboration between medical and dental researchers on the potential entry route into the bloodstream.
The team’s model proposes that the mouth provides a reservoir for the virus to thrive in the saliva and any breach in oral immune defences makes it easier for the virus to enter the bloodstream. Moving from blood vessels in the gingiva, the virus is hypothesised to pass through the neck and chest veins to the heart before being pumped into the pulmonary arteries and small vessels in the lung base and periphery.
Co-author Dr Iain Chapple, professor of periodontics at the University of Birmingham, commented: “This model may help us understand why some individuals develop COVID-19 lung disease and others do not. It could also change the way we manage the virus—exploring cheap or even free treatments targeted at the mouth and, ultimately, saving lives.”
“Studies are urgently required to further investigate this new model, but in the meantime, daily oral hygiene and plaque control will not only improve oral health and well-being, but could also be life-saving in the context of the pandemic,” Chapple explained.
This discovery could make effective oral healthcare a potentially life-saving action. For this reason, the researchers have recommended taking simple, but effective, daily steps to maintain oral hygiene and reduce factors contributing to periodontal disease, such as the build-up of plaque. These measures include the regular use of mouthwashes which could help lower the risk of transmission of the virus from the mouth to the lungs in those with COVID-19 and help prevent severe infection.
The study, titled “The COVID-19 pathway: A proposed oral-vascular-pulmonary route of SARS-CoV-2 infection and the importance of oral healthcare measures”, was published online in the Journal of Oral Medicine and Dental Research on 20 April 2021.