COVID-19 could pass into people’s lungs from saliva with the virus moving directly from the mouth to the bloodstream, particularly if they are suffering from gum disease, according to an international team of researchers.
The blood vessels in the lungs, rather than the airways, are initially affected in COVID-19 lung disease with high concentrations of the virus in saliva and periodontitis associated with increased risk of death, the researchers said.
Dental plaque accumulation and periodontal inflammation further intensify the likelihood of the SARS-CoV-2 virus reaching the lungs and causing more severe cases of the infection, the researchers said.
This discovery could make effective oral healthcare potentially lifesaving, the researchers said, recommending that the public take simple but effective daily steps to maintain oral hygiene and reduce factors contributing to gum disease such as plaque buildup.
In fact, the researchers said, specific ingredients of some cheap and widely available mouthwash products are highly effective at inactivating the SARS-CoV-2 virus.
Use of these specific mouthwash products and other simple oral hygiene measures could help reduce the risk of transmission of the virus to the lungs in those with COVID-19 and help prevent severe instances of the infection, the researchers said.
Initial observations of lung CT scans from patients suffering from COVID-19 lung disease by radiologist Dr. Graham Lloyd-Jones of Salisbury District Hospital led to a collaboration between medical and dental researchers on the potential entry route into the bloodstream.
“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,” said coauthor Iain Chapple, professor of periodontology at the University of Birmingham.
“Gum disease makes the gums leakier, allowing microorganisms to enter into the blood. Simple measures such as careful toothbrushing and interdental brushing to reduce plaque buildup, along with specific mouthwashes, or even saltwater rinsing to reduce gingival inflammation could help decrease the virus’ concentration in saliva and help mitigate the development of lung disease and reduce the risk of deterioration to severe COVID-19,” Chapple said.
The researchers included experts from Salisbury District Hospital in the United Kingdom, the University of Birmingham in the United Kingdom, and the Mouth-Body Research Institute in Los Angeles and Cape Town, South Africa.
Their new model is based on the mouth providing a breeding ground for the virus to thrive, with any breach in oral immune defenses making it easier for the virus to enter the bloodstream.
Moving from blood vessels in the gums, the virus would pass through neck and chest veins, reaching the heart before being pumped into pulmonary arteries and small vessels in the lung base and periphery.
“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 lifesaving in the context of the pandemic,” said Chapple.
The study, “The COVID-19 Pathway: A Proposed Oral-Vascular-Pulmonary Route of SARS-CoV-2 Infection and the Importance of Oral Healthcare Measures,” was published by The Journal of Oral Medicine & Dental Research.