Table 1. Distribution of S. pneumoniae serotypes based on their susceptibilities to PCG.

Category	Sub-category	Total	Susceptibility to PCG (µg/ml)			p-value
			PSSP	PISP	PRSP	DRSP v.s. PSSP
Gender	Female	125 (49.8%)	50 (19.9%)	48 (19.1%)	27 (10.8%)	p = 0.362
	Male	126 (50.2%)	43 (17.1%)	56 (22.3%)	27 (10.8%)
Age	0–2	92 (36.7%)	16 (6.4%)	50 (19.9%)	26 (10.4%)	p<0.001*
	3–5	37 (14.7%)	16 (6.4%)	17 (6.8%)	4 (1.6%)
	6–12	25 (10%)	18 (7.2%)	7 (2.8%)	0 (0%)
	13–20	7 (2.8%)	4 (1.6%)	2 (0.8%)	1 (0.4%)
	21–50	72 (28.7%)	30 (12.0%)	22 (8.8%)	20 (8.0%)
	≥51	18 (7.2%)	9 (3.6%)	6 (2.4%)	3 (1.2%)
Origin	Middle ear fluids	57 (22.7%)	21 (8.4%)	27 (10.8%)	9 (3.6%)	p = 1.000
	Nasal discharge/Sinus aspirates	88 (35.1%)	37 (14.7%)	34 (13.5%)	17 (6.8%)	p = 0.273
	Pharyngeal secretions	106 (42.2%)	35 (13.9%)	43 (17.1%)	28 (11.2%)	p = 0.291
Serotype	1	2 (0.8%)	1 (0.4%)	0 (0%)	1 (0.4%)	p = 1.000
	3	14 (5.6%)	13 (5.2%)	1 (0.4%)	0 (0%)	p<0.001
	4	1 (0.4%)	0 (0%)	0 (0%)	1 (0.4%)	p = 1.000
	6A	16 (6.4%)	6 (2.4%)	6 (2.4%)	4 (1.6%)	p = 1.000
	6B	37 (14.7%)	14 (5.6%)	17 (6.8%)	6 (2.4%)	p = 1.000
	9V	5 (2.0%)	3 (1.2%)	2 (0.8%)	0 (0%)	p = 0.667
	14	20 (8.0%)	2 (0.8%)	13 (5.2%)	5 (2.0%)	p = 0.002
	15B	7 (2.8%)	4 (1.6%)	3 (1.2%)	0 (0%)	p = 0.429
	19A	5 (2.0%)	4 (1.6%)	1 (0.4%)	0 (0%)	p = 0.064
	19F	52 (20.7%)	8 (3.2%)	25 (10.0%)	19 (7.6%)	p<0.001
	23F	41 (16.3%)	11 (4.4%)	18 (7.2%)	12 (4.8%)	p = 0.029
	G23	6 (2.4%)	4 (1.6%)	2 (0.8%)	0 (0%)	p = 0.198
	Others	45 (17.9%)	23 (9.2%)	16 (6.4%)	6 (2.4%)	p = 0.040
Total		251 (100%)	93 (37.1%)	104 (41.4%)	54 (21.5%)

G23: serogroup 23 strains except serotype 23F. PCG: penicillin G. PSSP: penicillin susceptible S. pneumoniae. PISP: penicillin intermediately resistant S. pneumoniae. PRSP: penicillin resistant S. pneumoniae. DRSP: PRSP+PISP. Others: serotypes not included in 23 PPV.

^*comparison between ≤2 y.o. vs. ≥3 y.o.