Table 2.

Clinical features by pertussis vaccination history [cases (%)].

	Vaccinated group (n = 112)	Unvaccinated group (n = 107)	X2	P
Spastic cough	103 (91.96)	97 (88.99)	0.568	.451
Whoop	36 (32.14)	38 (34.86)	0.183	.668
Cyanosis	25 (22.3)	40 (36.70)	5.499	.019
Apnea	9 (8.04)	17 (15.60)	3.042	.081
Fever	27 (24.11)	27 (24.77)	0.013	.909
Rhinorrhea	60 (53.57)	55 (50.46)	0.214	.643
Nasal obstruction	38 (33.93)	34 (31.19)	0.188	.664
Positive bacterial culture	27 (45.8)	32 (54.3)	0.778	.378
inpatient days (d, $\overline{\text{x}}\pm \text{s}$)	7.57 ± 3.03	9.61 ± 8.10	17.378	.564
WBC (×109/L, $\overline{\text{x}}\pm \text{s}$)	15.09 ± 7.46	16.04 ± 9.42	169.996	.442
L (%, $\overline{\text{x}}\pm \text{s}$)	67.49 ± 11.51	67.42 ± 13.79	130.646	.280

WBC = White blood cell.