Table 1. Background information for patients with influenza-like symptoms from whom clinical specimens were collected.

Clinic	Number of samples	Gender			Age		Specimen collection
		Male	Female	Unknowna	Mean years (Range)	Unknowna	Days after onset	Unknowna
A	40	18	21	1	26.4 (1–69)	1	0.8±0.6	1
B	10	6	4	0	28.3 (10–51)	0	1.2±0.4	1
C	79	39	40	0	29.7 (9–76)	0	1.0±0.7	0
D	70	28	40	2	24.5 (2–62)	2	1.1±0.9	3
E	17	6	11	0	30.8 (4–88)	2	1.9±2.8	0
F	39	16	23	0	27.4 (3–63)	1	1.1±0.7	1
G	30	18	12	0	31.8 (2–73)	0	1.5±0.7	0
H	48	24	23	1	25.5 (0–86)	0	0.8±0.7	1
I	38	21	16	1	34.1 (12–62)	0	1.3±0.9	2
J	39	20	19	0	33.6 (9–60)	7	1.0±0.6	6
K	22	11	11	0	31.3 (20–45)	0	1.7±0.6	0
L	48	30	18	0	40.7 (21–78)	1	1.7±1.8	0
M	62	34	28	0	34.7 (2–87)	0	1.5±1.5	3
Total	542	271	266	5	30.5 (0–88)	14	1.2±1.2	18

^aInformation could not be obtained from the answers to the questionnaires.