History
Take a detailed history to ascertain the level of risk for COVID-19 and assess the possibility of other
causes. Travel history is key; it is crucial for timely diagnosis and to prevent further transmission.
The diagnosis should be suspected in patients with fever and/or signs/symptoms of lower respiratory
illness (e.g., cough, dyspnoea) who reside in or have travelled to a country/area or territory reporting local
transmission of COVID-19 or who report close contact with a confirmed or probable case of COVID-19 in
the 14 days prior to symptom onset.
Clinical presentation
The clinical presentation resembles viral pneumonia, and the severity of illness ranges from mild to
severe. Approximately 80% of patients present with mild illness, 14% present with severe illness, and 5%
present with critical illness. Early reports suggest that illness severity is associated with older age and the
presence of underlying health conditions.[11]
Some patients may be minimally symptomatic or asymptomatic. Large-scale screening in non-endemic
areas may pick up more of these types of patients. A milder clinical course has been reported in cases
identified outside of China, with most patients being healthy adults.[52]
Based on an early analysis of case series, the most common symptoms are:[4] [5] [6]
• Fever
• Cough
• Dyspnoea
• Myalgia
• Fatigue.
Less common symptoms include:
• Anorexia
• Sputum production
• Sore throat
• Confusion
• Dizziness
• Headache
Rhinorrhoea
• Chest pain
• Haemoptysis
• Diarrhoea
• Nausea/vomiting
• Abdominal pain.
Approximately 90% of patients present with more than one symptom, and 15% of patients present with
fever, cough, and dyspnoea.[5] It appears that fewer patients have prominent upper respiratory tract or
gastrointestinal symptoms compared with SARS, MERS, or influenza.[4] [5] Patients may present with
nausea or diarrhoea 1 to 2 days prior to onset of fever and breathing difficulties.[6] Most children present
with mild symptoms, without fever or pneumonia. However, they may have signs of pneumonia on chest
imaging despite having minimal or no symptoms.[8] [9] [10] Retrospective reviews of pregnant women
with COVID-19 found that the clinical characteristics in pregnant women were similar to those reported
for non-pregnant adults.[30] [31] A retrospective case series of 62 patients in Zhejiang province found
that the clinical features were less severe than those of the primary infected patients from Wuhan City,
indicating that second-generation infection may result in milder infection. This phenomenon was also
reported with MERS.[53]
Perform a physical examination. Patients may be febrile (with or without chills/rigors) and have obvious
cough and/or difficulty breathing. Auscultation of the chest may reveal inspiratory crackles, rales, and/or
bronchial breathing in patients with pneumonia or respiratory distress. Patients with respiratory distress
may have tachycardia, tachypnoea, or cyanosis accompanying hypoxia.