Could poor oral hygiene increase the risk of COVID-19 infection?

In a new paper, Victoria Sampson looks into how better oral health care could reduce the risk of complications from COVID-19In a new paper, Victoria Sampson looks into how better oral health care could reduce the risk of complications from COVID-19.

A paper most recently published in the British Dental Journal by Sampson et al explores the potential connection between poor oral health and COVID-19 complications. The paper explores whether oral bacteria may play a role in exacerbating COVID-19 infections and encouraging the development of complications such as pneumonia and acute respiratory distress syndrome – the main complications from COVID-19.

For years, the dental profession has been aware of the direct connection between the mouth and the body. Many believe that the mouth is the mirror to one’s health. This connection is mutual. When there is poor systemic health, the mouth often reacts with inflammation, xerestomia, periodontal disease and increased decay. When we take certain medications or undergo hormonal changes, our mouth reflects this. Furthermore, many nutritional deficiencies and gastrointestinal diseases are first diagnosed in the mouth. Many believe the mouth is an extension of the gastrointestinal tract.

With this being said, the connection between the mouth and the body is often disregarded or forgotten. Many of us treat the mouth as a single entity. They attempt to treat oral disease without thinking of the consequences on the body. Or whether it could have been caused by systemic disease instead. With the pandemic we find ourselves in, it is important to treat patients holistically and to reduce the levels of oral bacteria. Not only to maintain a healthy mouth, but also a healthy body.

On the 30 January, the World Health Organisation (WHO) identified a new virus, SARS-CoV-2, to be a global emergency. It urged immediate lockdown to reduce the risk of the transmission of this fatal virus. It seemed as if the public was discovering new and wonderful things at the same rate as scientists. This novel organism continued to defy all boundaries. One thing that struck abnormal was who the virus fell victim to, with the virus having a certain affinity to those with diabetes, high blood pressure, heart disease, obesity and/or heart disease.

Crucial role of bacteria

Furthermore, the mean age of patients developing severe complications was 69 years old, with the elderly of our population deemed more vulnerable to developing complications from COVID-19. The complications commonly associated are acute respiratory distress syndrome, pneumonia, sepsis, septic shock and blood clots. Patients are more likely to die from these post-viral complications highlighted, as opposed to solely from COVID-19.

This is not the first time that a viral infection causes complications that eventually result in death. During the influenza pandemic in 1918, the primary cause of death was not from the virus itself. Instead, it was from bacterial superinfections. Or HIV, a virus where one of the primary causes of death is bacterial pneumonia.

Despite the proven importance of superinfections in the severity of viral diseases, they are often understudied during respiratory infection outbreaks such as this one. The diagnosis of a superinfection is complex and time consuming. It is suggested therefore, that the role of bacterial superinfections be investigated further during this pandemic.

Studies have shown that 80% of patients in ICU with COVID-19 had an exceptionally high bacterial load and required antibiotics. Furthermore, in Italy, 84% of patients admitted into ICU for COVID-19 required antibiotics. This supports the idea that bacteria plays a huge role in the development and severity of COVID-19 infections.

Why oral bacteria?

Whilst the idea of bacterial superinfections during a COVID-19 infection is understood amongst the medical community, the idea of this bacteria originating from the mouth is novel. The four main comorbidities associated with an increased risk of complications and death from COVID-19 are also associated with altered oral biofilms and periodontal disease.

Periodontopathic bacteria are implicated in systemic inflammation, bacteraemia, and pneumonia. Patients exhibiting severe complications from COVID-19 also often display high levels of inflammatory markers (Interleukin 2, 6 and 10). These are the same markers that are increased in patients suffering from periodontal disease. Furthermore, bacteria present in the metagenome of patients severely infected with COVID-19 included high levels of Prevotella intermedia, Staphylococcus aureus, and Fusobacterium nucleatum. These are all usually commensal organisms in the mouth.

Oral bacteria are in an ideal location to be aspirated into the respiratory tract. They can help initiate or worsen conditions such as pneumonia or sepsis. Inadequate oral hygiene can therefore increase the risk of inter-bacterial exchanges between the lungs and mouth. This allows for respiratory infections and post-viral bacterial complications. A concern is that during a viral infection such as COVID-19, patients may be less likely to brush their teeth. This is exacerbated in patients suffering from severe complications who find themselves in ICU. They are unable to brush their teeth themselves and intubated on a ventilator.

Fear of transmission

The idea of ventilator associated pneumonia and poor oral health when intubated is a known fact and fortunately very avoidable. Numerous studies have shown that improved oral care can significantly reduce the incidence of ventilator-associated pneumonia in ICU patients. It can also reduce the risk of acquiring a bacterial superinfection.

Another concern is that fear has been instilled into patients who may be scared of visiting the dental practice. It must be stressed to patients and the public that oral health is directly connected to systemic health. A healthy mouth will help create a healthy body. Oral hygiene must be maintained – if not improved – during this pandemic in order to reduce bacterial load in the mouth and therefore the potential risk of bacterial superinfection. Oral care is so important. It has even been concluded that one in 10 pneumonia-related deaths in the elderly could be prevented by improving oral hygiene.

In conclusion, I want to leave you with the responsibility to improve your patients’ oral health, not only in the chair, but also at home. Many patients express concern of coming to the dental practice in fear of infection or transmission of COVID-19. Like with any trip out of the house there comes a risk. But visiting the dentist must be maintained and oral health must be of upmost importance. It is in our hands to reduce the bacterial load in the mouth and reduce the potential risk of bacterial superinfections arising from a COVID-19 infection.

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