Table 1.

The baseline characteristics and the exposure history of 105 healthcare workers as close contacts of COVID-19 patients.

Characteristics	All close contacts (n=105)	Seropositive close contacts (n=18)	Seronegative close contacts (n=87)	p value
Demographic feature
Age, years	30.0 (26.0-39.5)	27.0 (27.0-32.0)	31.0 (26.0-43.0)	0.203
Sex				0.260
Male	22 (20.95)	2 (11.11)	20 (22.99)
Female	83 (79.05)	16 (88.89)	67 (77.01)
General Symptoms	13 (12.38)	4 (22.22)	9 (10.34)	0.164
Fever	2 (1.90)	0 (0)	2 (2.29)	0.516
Headache	2 (1.90)	0 (0)	2 (2.29)	0.516
Sore throat	3 (2.86)	1 (5.56)	2 (2.29)	0.450
Cough	6 (5.71)	2 (11.11)	4 (4.60)	0.279
Myalgia	1 (0.95)	0 (0)	1 (1.15)	0.648
Diarrhea	3 (2.86)	0 (0)	3 (3.45)	0.424
Rhinorrhea	2 (1.90)	1 (5.56)	1 (1.15)	0.213
Relationship with the COVID-19 patient
Colleague	52 (49.52)	8 (44.44)	44 (51.72)	0.636
Doctor	17 (16.20)	7 (38.89)	10 (10.34)	0.004
Nurse	25 (23.81)	2 (11.11)	23 (26.43)	0.165
General service assistant	11 (10.47)	1 (5.56)	10 (11.49)	0.454
Exposure history
Close contacts of Patient No.
Patient 1	42 (40.01)	5 (27.7)	37 (43.53)	0.245
Patient 2	14 (13.33)	5 (27.78)	9 (10.34)	0.048
Patient 3	43 (40.95)	7 (38.89)	36 (41.38)	0.845
Patient 4	6 (5.71)	1 (5.56)	5 (5.75)	0.975
The extent of exposure
≥30 min at a distance of <1 meter	33 (31.43)	10 (55.56)	23 (26.44)	0.015
Disposable non-surgical face mask wearing	78 (74.29)	10 (55.56)	68 (78.16)	0.046
Swab sample collection	5 (4.76)	2 (11.11)	3 (3.45)	0.165
Exposure times
>10	24 (22.86)	3 (16.67)	21 (24.13)	0.492
5-9	18 (17.14)	3 (16.67)	15 (17.24)	0.953
0-4	63 (60.00)	12 (66.67)	51 (58.62)	0.526

Data are median (IQR), or n/N (%). p values were calculated by Mann-Whitney U test or χ² test, as appropriate.