Severe Covid-19 Infection and Coexisting Chronic Disease
Patients with severe SARS-CoV-2 (COVID-19) related conditions such as pneumonia, are frequently older patients, particularly those suffering chronic medical conditions including:
- Chronic Lung Disease
- Moderate to Severe Asthma
- Chronic Kidney Disease
- Liver Disease
Patients suffering from obesity, diabetes and hypertension, suffer the most unfavourable outcomes in COVID-19 infection requiring hospitalisation, ICU admission and artificial ventilation.
Patients with COVID-19 commonly display symptoms of a high fever, cough, breathlessness, and other complications associated with acute respiratory distress syndrome.
However the SARS-CoV-2 (COVID-19) infection may affect multiple organs including the kidneys and liver but appears to most commonly affect the respiratory system causing severe pneumonia.
Gum Disease Prevalence and General Health
Considerable evidence has been published since the 1980’s for a relationship between gum disease(periodontitis) and other chronic medical diseases.
Chronic periodontitis is very prevalent affecting around 30% of the overall population and up to 60% of older people. This represents a huge number of patients and a massive need for dental manpower to both diagnose and treat this huge pool of oral disease.
Risk Factors for Gum Disease:
While inadequate plaque control is a known causative factor for gum disease, there appears to be an additional common thread in the cause of this condition involving an excessive immunological response and an autoimmune nature to the destruction of the bone supporting the teeth.
It is known that those who suffer from the more severe forms of periodontitis often have a family history of gum disease and premature tooth loss.
This appears to relate to the genetic codes that are passed on by parents that determine everything from eye and hair colour to how the immune system functions. It has been stated that many of those with advanced chronic periodontitis exhibit a immunological “hyperactive inflammatory phenotype”.
Other Risk Factors
In addition to inadequate plaque control, other known risk factors for periodontitis include:
- Increasing age
- smoking including e-cigarettes, co-existing diabetes
- coexisting chronic medical conditions (chronic kidney disease, cardiac disease, liver disease)
Oral Bacteria and Respiratory Infection
In view of these findings it has been proposed that improving plaque control reducing the bacterial load of the mouth and improving oral health will contribute to reducing the risk of respiratory disease and the risk of more severe COVID-19 related conditions with a consequent reduction in the risk of ICU admission, artificial ventilation and death.
Covid Immune Response
The severity of COVID-19 illness appears to be related to an excessive immune response with the release of multiple Immune chemicals known as cytokines and lymphokines. This has been described as a “cytokine storm”.
The sudden massive immune activity leads to massive collateral tissue damage that can affect several organs.
Commonly the severe tissue damage is seen in the connective tissue of the lungs leading to a build up of tissue fluid and the collection of various immune cells within the lung tissues. This cellular (pneumocytes, lymphocytes, polymorphonuclear leukocytes) and tissue fluid collection in the lungs causes breathing to become difficult and ineffective hence the need for artificial ventilation.
Oral and Medical Health
Since the early 1980’s it has been reported that oral health has a significant impact on general health.
Gum disease known as chronic periodontitis is caused by oral biofilm (plaque) where bacterial waste products trigger an immune defence reaction by the host involving cellular and humoral immune reactions. These immune defence reactions lead to the release of multiple immune chemicals known as cytokines. These highly active immune chemicals transit through the body reaching distant organs having distant systemic effects.
It is these distant effects of immune substances that may enhance the development of systemic diseases including Alzheimer’s disease, diabetes, atherosclerotic coronary heart disease and cerebrovascular disease (stroke).
Research shows that poor oral health increases complications of systemic chronic diseases like diabetes, chronic kidney disease and liver disease.
Plaque and Pneumonia
High numbers of respiratory pathogens found in the oral cavity may also relate to the development of hospital-acquired pneumonia, the mechanism of which may involve aspiration of oral bacteria into the lungs and colonisation of the oropharynx and respiratory epithelium by bacteria that possess the capability to modify the host response to facilitate colonisation, infection and severe immune reactions.
General Health Effects Periodontitis
The opposite relationship has also been demonstrated where obesity and diabetes predispose to chronic periodontitis.
Effective personal oral hygiene and professional dental care reduces the prevalence of respiratory diseases in the high risk population in intensive care units.
Older adults and people of any age who have chronic medical conditions such as chronic lung disease, diabetes, heart conditions or chronic kidney disease are at high risk for developing severe illness due to SARS-CoV-2 infection.
Poor oral health increases the risk of developing or exacerbating chronic medical conditions. Therefore, improving oral health in people of any age reduces their risk of developing chronic medical conditions and may reduce the severity of COVID-19 disease.