Coronaviruses are a large family of viruses that infect a range of animal species including humans. Here they usually cause mild to moderate upper-respiratory tract illnesses, like the common cold. However, occasionally these viruses jump species, called a ‘spill-over’ event, and that has the potential to cause more serious disease. Three ‘spill-over’ coronaviruses have emerged in recent years: including SARS (severe acute respiratory syndrome) which was discovered in late 2002; MERS (Middle East respiratory syndrome), which began in 2012; and COVID-19, which started in China in December 2019 and is caused by the coronavirus known as SARS-CoV-2.1
Symptoms of this virus commonly include fever, tiredness and a dry cough. Other possible symptoms include shortness of breath, sore throat, loss of the sense of smell, with a few people reporting diarrhoea, nausea or a runny nose.2
The virus infects the lining of the pulmonary tract via ACE2 receptors, and destroys the bronchi and alveoli cell lining, specifically the goblet cells which produce mucus, and the ciliated cells which have fine hairs on the surface to remove excess mucus from the tract.3 The accumulated liquid and the resultant heightened immune response to the virus and the tissue damage results in pneumonia-like effects, which in severe cases causes acute respiratory distress syndrome (ARDS), which is often fatal.