I came across the article “Oral Hygiene and Severity of COVID-19” a couple of days ago that was recently written by Dr. Ananya Mandal, M.D.  Dr. Mandal discusses a study that was published in the latest issue of the British Dental Journal by a group of researchers in England.  What caught my interest was that she stated that British researchers have found a link between poor oral hygiene and severity of COVID-19 disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.  I have listed the highlights of her article as follows:

 Researchers to date have identified several risk factors that are associated with severe COVID-19 course of disease and outcome. While many patients infected with the virus recover without complications, some may need hospitalization, oxygen supplementation, and even ventilation. Some of the risk factors associated with poor outcome of the disease include high blood pressure, diabetes, obesity, and heart disease. They wrote that the main complications of COVID-19 include “blood clots, pneumonia, sepsis, septic shock, and ARDS (Acute respiratory distress syndrome).” These complications are seen mainly among those with comorbidities and bacterial overload, they wrote. 

This study explored the complications of COVID-19 seen among those with poor oral health and periodontal disease. The oral microbiome or the microbial flora of the mouth was explored and its connection with the COVID-19 outcome was analyzed. The authors wrote, “We explore the connection between high bacterial load in the mouth and post-viral complications, and how improving oral health may reduce the risk of complications from COVID-19.” 

The authors of the study wrote that during lung infection, there is a risk of aspirating the oral secretions into the lungs, which could cause infection. Some of the bacteria present in the mouth that could cause such infections include “Porphyromonas gingivalis, Fusobacterium nucleatum, Prevotella intermedia,” they wrote. They explained that periodontitis or infection of the gums is one of the most prevalent causes of harmful bacteria in the mouth. These bacteria lead to the formation of cytokines such as Interleukin 1 (IL1) and Tumor necrosis factor (TNF), which can be detected in the saliva and can reach the lungs leading to infection within them. Thus, the researchers wrote, “inadequate oral hygiene can increase the risk of inter-bacterial exchanges between the lungs and the mouth, increasing the risk of respiratory infections and potentially post-viral bacterial complications.” 

The team wrote, “Good oral hygiene has been recognized as a means to prevent airway infections in patients, especially in those over the age of 70”. Those with periodontal disease are at a 25 percent raised risk of heart disease, thrice the risk of getting diabetes, and 20 percent raised risk of getting high blood pressure, the researchers wrote. These are all risk factors of severe COVID-19 they wrote. 

This study concludes that 20 percent of the patients with COVID-19 progress to severe illness with high levels of “inflammatory markers (IL-2, IL-6, IL-10), bacteria, and neutrophil-to-lymphocyte count”. They noted that the oral microbial environment and COVID-19 could be linked. The four essential risk factors for severe COVID-19 (diabetes, high blood pressure, heart disease, and obesity) are also associated with poor oral hygiene, they wrote. They recommend “oral hygiene be maintained, if not improved, during a SARS-CoV-2 infection in order to reduce the bacterial load in the mouth and the potential risk of bacterial superinfection.” These precautions are particularly important for those with diabetes, heart disease and hypertension, they wrote.