What is COVID-19?
Coronaviruses are a large family of viruses with some causing less severe disease, such as the common cold, and others causing more severe disease, such as Middle East respiratory syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) coronaviruses.
According to current evidence, Coronavirus is primarily transmitted between people through respiratory droplets and has been detected in blood, faeces and urine. At the moment, human-to-human transmission is occurring extensively and spreading quickly.
COVID-19 presents with a range of symptoms of varying severity. There are also individuals that can carry the virus with no symptoms at all.
More common symptoms are fever, a new and continuous cough, shortness of breath, fatigue, loss of appetite, anosmia (loss of smell) and ageusia (loss of taste). Non-specific symptoms include shortness of breath, fatigue, loss of appetite, myalgia, sore throat, headache, nasal congestion, diarrhoea, nausea and vomiting.
Atypical symptoms, such as delirium and reduced mobility, can present in older and immunocompromised people, often in the absence of a fever.
Of people who develop symptoms, current data indicate that 40% have mild symptoms without hypoxia (problems with the level of oxygen in the blood) or pneumonia, 40% have moderate symptoms and non-severe pneumonia, 15% have significant disease including severe pneumonia, and 5% experience critical disease with life-threatening complications.
Critical disease includes acute respiratory distress syndrome (ARDS), sepsis, septic shock, cardiac disease, thromboembolic events, such as pulmonary embolism and multi-organ failure.
Evidence is growing that the longer-term consequences of more severe complications associated with the inflammatory response may be considerable in those who experience critical and life-threatening illness. Rare neurological and psychiatric complications, which can also occur in patients without respiratory symptoms, include stroke, meningo-encephalitis, delirium, encephalopathy, anxiety, depression and sleep disturbances.
Risk of severe disease and death is higher in people who are older, male, from deprived areas or from certain non-white ethnicities. Certain underlying health conditions, as well as obesity, increase risk in adults.
Infants and children generally appear to experience milder symptoms than adults and further evidence is needed about the association between underlying conditions and risk of COVID-19 disease in children. A rare presentation of multisystem inflammatory syndrome temporarily associated with COVID-19 in children and adolescents has been noted and there is a lot of further research being done in this area.