Table 1

Summary of case definitions for population testing for SARS-CoV-2 in England

Time periodCase definition
Before 7 February 2020 Epidemiological criteria
In the 14 days before the onset of illness:

  • travel to China OR contact with a confirmed case of COVID-19;


and Clinical criteria

  • severe acute respiratory infection requiring admission to hospital with clinical or radiological evidence of pneumonia or acute respiratory distress syndrome;


OR

  • acute respiratory infection of any degree of severity, including at least one of shortness of breath (difficult breathing in children) or cough (with or without fever);


OR

  • fever with no other symptoms.

From 7 February 2020 Epidemiological criteria
In the 14 days before the onset of illness:

  • travel to affected countries, including transit, for any length of time, in these countries OR contact with a confirmed case of COVID-19;


and Clinical criteria

  • severe acute respiratory infection requiring admission to hospital with clinical or radiological evidence of pneumonia or acute respiratory distress syndrome;


OR

  • acute respiratory infection of any degree of severity, including at least one of shortness of breath (difficult breathing in children) or cough (with or without fever);


OR

  • fever with no other symptoms.

From 13 March 2020 Inpatient definition

  • requiring admission to hospital;


and

  • have either clinical or radiological evidence of pneumonia;


OR

  • acute respiratory distress syndrome;


OR

  • influenza-like illness (fever ≥37.8°C and at least one of the following respiratory symptoms, which must be of acute onset: persistent cough (with or without sputum), hoarseness, nasal discharge or congestion, shortness of breath, sore throat, wheezing or sneezing.

  • *Imported cases were defined as cases with travel to countries with known COVID-19 circulation at the time or with contact with a confirmed case while abroad within a maximum incubation period of their onset of symptoms.

  • †Secondary cases were defined as cases that had contact with a confirmed or probable/suspected case in the UK and did not fit the definition of an imported case.

  • ‡Sporadic cases were defined as cases with no travel history to countries with known COVID-19 circulation, and no known contact with a confirmed case.

  • SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.