Graham's Research findings

This is the more detailed account of the research and what has led to Salisbury Hospital adopting measure for better inpatient oral care.  Lots of food for thought here.

Initially, my work was based on gaining an understanding of the appearances of the lung disease in COVID-19 on X-rays and scans. The pattern is totally unlike any pneumonia we have seen before. The airways of the lungs are not inflamed, as occurs in influenza. It’s the blood vessels which are abnormal. This raised an important question in my mind. Could the virus be getting to the lungs via the bloodstream?

I went back to square one.

We know that the virus first infects the nasal passages and reproduces in the mouth. In those with COVID-19, a single teaspoon of saliva contains 500 million copies of the virus. The higher the viral load (number of viruses) in the saliva, the more likely you are to get severe COVID-19. High viral load in saliva is a better predictor of death than a patient’s age.

Importantly, gum disease is highly associated with severe COVID-19. Dental researchers, who for months had known about this connection, were working on the basis that inflammation in the mouth due to gum disease might be worsening the disease elsewhere in the body - but they didn’t know what was going on in the lungs. I wondered if the explanation could be more straightforward.

We know that other bugs can escape the mouth, enter the bloodstream and infect the heart or lungs. Perhaps the same could be happening with SARS-CoV-2 in the development of COVID-19. Simply put, if you have bleeding gums, there would be no barrier between the millions of viruses in your saliva and the veins of the mouth. From here, the virus would first be delivered to the lung blood vessels, exactly where we see the lung damage.

All the risk factors for severe gum disease are the same as for severe COVID-19. These include increasing age, male sex, all the racial and genetic factors including blood group, diseases such as cardiovascular disease, diabetes, kidney disease, obesity, COPD and smoking. Those who find it difficult to care for their mouths have also been more affected by COVID-19, such as those with dementia, learning difficulties or physical difficulties. It seems that gum disease could be a converging or even a main risk factor for severe COVID-19.

If this were true, this would mean that oral health would become central to our understanding of how the lung disease develops. Furthermore, an improvement in oral healthcare could be beneficial in treating the illness or possibly even help prevent development of the lung disease in those infected.

In February 2021, I published the theory describing the potential for the passage of SARS-CoV-2 from the mouth to the lungs via the blood vessels. I then teamed up with gum disease experts to publish a scientific hypothesis in April. The paper was reported in more than 100 news publications globally and we were interviewed on SKY News and BBC Radio.

We proposed that use of simple oral hygiene measures, such as toothbrushing, could be beneficial for those with COVID-19. Also, research at Cardiff University has shown there are specific mouthwashes which kill the virus in the test tube in 30 seconds. We suggested that these products could benefit patients with COVID-19. I am now working with research groups elsewhere in the UK to answer that exact question and to prove the pathway of delivery of the virus from the mouth to the lungs via the bloodstream.

In the meantime, at Salisbury Hospital, we are forging ahead. With the enthusiastic backing of the Trust’s executive team, we have initiated a hospital-wide quality improvement project to focus on oral healthcare. Experts from Health Education England have started additional training for our nurses. We are aiming for excellence in oral healthcare for our COVID-19 patients, who now all receive a supply of one of the specific mouthwashes. The measures we are putting in place are based on existing evidence that shows paying attention to oral healthcare for inpatients is beneficial, shortening hospital stay and even reducing death rate.

The project has gained the enthusiastic attention of those at the very top of dentistry, public health, infection control and medical research in the UK. As soon as we are up and running in Salisbury, we will be sharing our ideas and practices with as many other hospitals as possible.

I am extremely grateful for the generous gift of £350 which the League of Friends offered so we could buy the first consignment of mouthwash to get the project underway. The hospital is now funding the project which was formally launched on 1st November 2021.

Nature Outlook article


Salisbury Hospital COVID-19 Mouth Care Guidance


Original theory - Radiology Masterclass - February 2021


Scientific hypothesis. The COVID-19 Pathway: A hypothetical April 2021


Dr Graham Lloyd-Jones

Consultant Radiologist, Salisbury District Hospital