on the epidemiology, virology, transmission, and clinical features of COVID-19 is available.COVID-19 can present with a range of symptoms of varying severity.
It is estimated that 1 in 3 people have COVID-19 without displaying any symptoms.The main symptoms include fever, a new and continuous cough, anosmia (loss of smell) and ageusia (loss of taste).Examples of other symptoms include shortness of breath, unexplained tiredness or fatigue, loss of appetite, myalgia (muscle ache), sore throat, headache, nasal congestion (stuffy nose), runny nose, diarrhoea, nausea and vomiting.
Older people may present with less common symptoms.In some individuals cough or a loss of, or change in, normal sense of smell or taste may persist for several weeks.
This is not considered an indication of ongoing infection when other symptoms have resolved.It is likely that individuals who are infected with SARS-CoV-2 and who are asymptomatic can still transmit virus to others.In most cases, transmission of SARS-CoV-2 occurs from 9 days before symptom onset to 15 days after symptom onset, with most transmission occurring 3 days before symptom onset to 5 days after symptom onset.Severely immunocompromised patients can remain infectious for a much longer period.There is some evidence that children may be less infectious, and are infectious for a shorter period of time, compared with adults.Positive lateral flow device (LFD) tests have been shown to be associated with high viral load in infectious cases.