CORONAVIRUS SARS-CoV-2/COVID-19

SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) is a coronavirus that has been spreading globally since December 2019. Infection can differ greatly and the severity of infection can also vary. The disease is known as COVID-19 (Corona Virus Disease 2019). There are different variants of SARS-CoV-2 caused by mutations, that is changes in the genome of the coronavirus. The characteristics of each variant, such as its disease course and transmissibility, can vary.

The SARS-CoV-2 coronavirus causes infections of the respiratory tract, but can also affect other organs of the body. COVID-19 is a systemic disease, meaning it affects the whole body. The symptoms and severity of the COVID-19 disease vary greatly. Some people experience no symptoms whatsoever. However, people can also experience severe symptoms or even die from the disease. Symptoms alone do not indicate infection by SARS-CoV-2.

Common symptoms include coughing, fever, head cold, and sore throat, as well as impaired sense of taste or smell. People may also experience other symptoms, such as shortness of breath, head and joint pain and general lethargy. Some sufferers report gastrointestinal symptoms, including nausea, loss of appetite, vomiting, abdominal pain and diarrhoea. Other symptoms have also been reported.

Severe progression of the disease can lead to complications, such as pneumonia, inflammatory diseases of the nervous system, brain or cerebral membrane, cardiovascular, liver or kidney disease. Impaired circulation, blood clots (embolisms) and inflammation of the cardiac muscle can also occur. The most severe inflammatory reactions (hyperinflammatory syndrome) can result in organ failure.

Symptoms of the disease can still be present or reoccur weeks or months after being infected by COVID-19. Long-term health consequences that continue for more than four weeks after being infected with SARS-CoV-2 are referred to as long COVID. The most common symptoms of 'long COVID' include tiredness, exhaustion and impaired capacity (fatigue), shortness of breath, concentration and memory problems, sleep disorders, muscle weakness and muscle pain, as well as mental problems including symptomatic depression.

Children infected with SARS-CoV-2 usually experience mild symptoms or no symptoms at all, although they can also suffer from more severe symptoms and long-term health consequences. Paediatric Inflammatory Multisystemic Syndrome (PIMS) is one of the rare complications found in children and adolescents. This is an inflammatory condition characterised by fever, gastrointestinal symptoms and cardiac problems. It often requires intensive medical treatment although its treatment is now very good.

It usually takes three to five days from being infected with the SARS-CoV-2 coronavirus for the symptoms to occur, but this can also vary.

Infected individuals can infect others before they develop symptoms themselves. The risk of infection is highest in the five or so days around the onset of symptoms. With milder cases, a person's ability to infect another individual generally decreases continuously and markedly over the first ten days after the onset of symptoms. In exceptional cases, people suffering from a more severe progression of the disease or who are immunodeficient could also be contagious for much longer.

Younger people and people without a known underlying condition can also suffer more severe cases of COVID-19. However, more severe cases have been observed more frequently among the following groups of people:

• Elderly people,
• Men,
• Smokers,
• Overweight or seriously obese people,
• Pregnant women,
• People with Down's syndrome (trisomy 21),
• People with certain underlying conditions of the cardiovascular system (such as coronary heart disease and high blood pressure), chronic lung diseases (such as COPD), chronic kidney and liver diseases, neurological-psychiatric diseases (such as dementia), diabetes, cancer, weakened immune system (possibly caused by a disease or by taking medication that weakens the immune system, such as cortisone).