Patient characteristics and setting  Facility cases: confirmed case: positive RT‐PCR test result obtained by a throat swab. Test was repeated when the first test was negativeFacility controls: pneumonia patients confirmed not to be infected by SARS‐Cov2 (2 PCR tests)Country: ChinaDates: 19 January 2020‐6 February 2020Symptoms and severity: pneumonia was defined as patients with at least 1 clinical symptom (i.e. cough, sputum, fever, dyspnoea, or pleuritic chest pain), a finding of either coarse crackles on auscultation or elevated inflammatory biomarkers, and observation of a new pulmonary opacification on chest CTDemographics: median age +‐ SD cases 50.36 +‐ 15.5, controls 43.59 +‐ 16.02, gender distribution cases (M/F: 8/3), controls (M/F: 7/15)Exposure history: cases 8/11, controls 7/22 (in the last 14 days with patients with fever or respiratory symptoms or with known cases)