Table 1. Demographic and clinical characteristics of confirmed COVID-19 cases related with potential pre-symptomatic transmission in three infection clusters, Shanghai, China, January–February 2020 (n = 8).

Cluster	Case	Age (years)	BMI	Smoking	Comorbidity	Fever (°C)	Other respiratory symptoms	Influenza antigen test	White blood cell (x 109/L, (norm 4.0–10.0)	Chest computed tomography scan	Clinical outcome
Cluster 1	Case 1A	20–30	30.4	No	None	38.0–38.5	NA	Influenza A and B negative	4.1–6.0	Scattered patches and increased density in both lungs	Recovery
	Case 1B	20–30	35.5	No	None	37.6–39.0	Headache, productive cough, myalgia	Influenza B positive	4.0	Multiple ground glass opacities in both lungs	Death
	Case 1C	20–30	22.9	No	None	37.3–38.7	NA	NA	3.6	Infection in left lung	Recovery
Cluster 2	Case 2A	50–60	NA	Yes	None	NA	Cough	NA	NA	NA	Recovery
	Case 2B	60–70	22.6	Yes	Diabetes mellitus	37.3–38	NA	NA	3.8–4.2	Infectious lesions of both lungs and thin nodular shadow of left lung	Recovery
	Case 2C	30–40	28.7	No	None	37.7	Light productive cough, diarrhoea	NA	NA	NA	Recovery
Cluster 3	Case 3A	60–70	19.7	No	None	37.6–38.5	Chills	NA	4.4	Two patchy ground glass opacity high-density shadows in right lung	Death
	Case 3B	80–90	19.8	No	Hypertension, cardiac disease, COPD	38.2	Poor appetite, dry cough	Influenza A and B negative	7.2	Interstitial hyperplasia and infection of both lungs	Death

BMI: body mass index; COPD: chronic obstructive pulmonary disease; COVID-19: coronavirus disease; NA: not available.