Facility cases: single sputum or throat swab test RT‐PCR‐positive pneumoniaFacility controls: for non‐COVID‐19 confirmation: 3 consecutive negative throat swabs or sputum sampling every other day during first 7 days of admissionCountry: China, AnhuiDates: 23 January 2020‐5 February 2020Symptoms and severity:fever cough sore throat headache fatigue diarrhoea chest tightness abnormal lung auscultation Demographics: mean age (cases/controls): 48 (IQR 27~56)/35 (IQR 27~46) in COVID‐19 and non‐COVID‐19 patients, respectively; F/M (cases/controls): 8 (42.11%)Exposure history: all patients had a history of exposure to confirmed cases of 2019‐nCoV or travel to Hubei before illness. Investigators interviewed each patient and their relatives, where necessary, to determine exposure or close contact histories during the 2 weeks before the illness onset