Table 1.

Characteristics of laboratory-confirmed COVID-19 cases in Guangzhou from Jan 7 to May 17, 2020.

Characteristics	Total (n = 745) No./total no.(%)	Primary cases (n = 496) No./total no.(%)	Infected close contacts (n = 249) No./total no.(%)	P value
Gender, female	324/745 (43.5%)	206/496 (41.5%)	118/249 (47.4%)	.15
Age, Mean (SD)	38.8 (16.9)	38.7 (16.2)	39.0 (18.2)	.84
Region				.16
China	560/745 (75.2%)	383/496 (77.2%)	177/249 (71.1%)
Africa	157/745 (21.1%)	100/496 (20.2%)	57/249 (22.9%)
Asia (out of China)	5/745 (0.7%)	3/496 (0.6%)	2/249 (0.8%)
Europe	12/745 (1.6%)	4/496 (0.8%)	8/249 (3.2%)
North America	8/745 (1.1%)	4/496 (0.8%)	4/249 (1.6%)
Oceania	1/745 (0.1%)	1/496 (0.2%)	0/249 (0.0%)
South America	2/745 (0.3%)	1/496 (0.2%)	1/249 (0.4%)
Cases type				<.01
Imported cases	438/745 (58.8%)	336/496 (67.7%)	102/249 (41.0%)	<.01
Imported from Hubei	214/438 (48.9%)	162/336 (48.2%)	52/102 (50.1%)
Out of Hube (in China)	53/438 (12.1%)	29/336 (8.6%)	24/102 (24.4%)
Imported from overseas	171/438 (39.0%)	145/336 (43.2%)	26/102 (25.5%)
Local cases	307/745 (41.2%)	160/496 (32.3%)	147/249 (59.0%)	<.01
Associated with imported cases from Hubei	63/307 (20.5%)	19/160 (11.9%)	44/147 (29.9%)
Associated with imported cases from overseas	208/307 (67.8%)	116/160 (72.5%)	92/147 (62.6%)
Infected source cases unknown	36/307 (11.7%)	25/160 (15.6%)	11/147 (8.1%)
Cluster	419/745 (56.2%)	195/496 (39.3%)	224/249 (90.0%)	<.01
Household cluster	342/419 (81.6%)	161/195 (82.6%)	181/224 (80.8%)	.64
Case of severity				.01
Asymptoms	275/745 (36.9%)	161/496 (32.5%)	114/249 (45.8%)
Symptoms	412/745 (55.3%)	288/496 (58.0%)	124/249 (49.8%)
Severe	57/745 (7.7%)	46/496 (9.3%)	11/249 (4.4%)
Death	1/745 (0.1%)	1/496 (0.2%)	0
Time from onset to diagnosis, mean (SD)	4.5 (4.4)	5.2 (4.7)	3.22 (3.3)	<.01
Time from onset to quarantine, mean (SD)	1.9 (5.2)	2.9 (5.4)	-0.29 (4.0)	<.01