2.

Etiologies distribution in different regions and years

Etiologies	Years							Regions
	2012 [n (%)]	2013 [n (%)]	2014 [n (%)]	2015 [n (%)]	2016 [n (%)]	Adjusted P-value		Nanjing [n (%)]	Suzhou [n (%)]	Taizhou [n (%)]	Adjusted P-value
*Fisher's exact test was used.
Flu A	58 (8.20)	57 (8.40)	26 (3.90)	12 (2.00)	56 (8.50)	<0.001		114 (7.43)	49 (4.18)	44 (7.20)	0.002
Flu B	22 (3.10)	3 (0.40)	21 (3.10)	16 (2.60)	22 (3.40)	0.009		61 (3.99)	6 (0.50)	15 (2.47)	<0.001
Flu C	4 (0.60)	3 (0.40)	3 (0.40)	1 (0.20)	2 (0.30)	0.852*		8 (0.50)	5 (0.40)	0 (0.00)	0.228*
RSV	13 (1.80)	5 (0.70)	45 (6.70)	42 (6.90)	28 (4.30)	<0.001		88 (5.70)	43 (3.70)	14 (2.33)	0.001
ADV	29 (4.10)	25 (3.70)	29 (4.30)	31 (5.10)	26 (4.00)	0.765		57 (3.74)	48 (4.07)	32 (5.19)	0.287
HRV	62 (8.80)	39 (5.70)	31 (4.60)	32 (5.30)	47 (7.20)	0.014		108 (7.04)	18 (1.52)	40 (6.43)	<0.001
hCoV-229E	3 (0.40)	3 (0.40)	1 (0.10)	3 (0.50)	4 (0.60)	0.771*		10 (0.63)	2 (0.16)	2 (0.26)	0.167*
hCoV-OC43	14 (2.00)	12 (1.80)	3 (0.40)	6 (1.00)	12 (1.80)	0.053*		31 (2.04)	13 (1.10)	5 (0.75)	0.050
hCoV-NL63	25 (3.50)	16 (2.40)	4 (0.60)	8 (1.30)	8 (1.20)	<0.001		53 (3.44)	10 (0.83)	4 (0.62)	<0.001
hCoV-HKU1	3 (0.40)	4 (0.60)	0 (0.00)	3 (0.50)	3 (0.50)	0.351*		10 (0.60)	1 (0.10)	2 (0.30)	0.058*
HSV	37 (5.20)	8 (1.20)	17 (2.50)	16 (2.60)	20 (3.00)	<0.001		56 (3.61)	18 (1.54)	26 (4.25)	0.001
S. pneumoniae	145 (20.50)	43 (6.30)	74 (11.10)	84 (13.90)	148 (22.60)	<0.001		367 (23.83)	96 (8.18)	78 (12.66)	<0.001
H. influenzae	62 (8.80)	5 (0.70)	51 (7.60)	98 (16.20)	131 (20.00)	<0.001		186 (12.08)	111 (9.54)	50 (8.19)	0.011
Total	477 (67.47)	223 (32.84)	305 (45.66)	352 (58.09)	507 (77.29)	<0.001		1 149 (74.66)	420 (35.96)	312 (51.23)	<0.001