1. Overall viral detection
1. In 103210 cases, 38355 cases were positive for at least one virus, with a total positive rate of 37.2%. There were 56250 males and 46960 females with an average age of (3.5 ± 2.6) years, of which 13984 were under 1 year old, 39552 were 1-3 years old, 32731 were 3-6 years old and 16943 were over 6 years old. Positive case in male and female were 21374 (38.0%) and 16981 (36.2%), respectively. The positive rate had statistically significant difference between male and female (χ2 = 37.0, P < 0.001).
2. Proportion of viral infection
Among the 38355 virus positive children, FLUA infection rate was the highest (18.2%), followed by ADV (13.0%), RSV (7.0%), and FLUB (2.3%), respectively (see Table 1 for details). A total of 1910 cases were infected by two or more viruses (multiple infection, 1.9%).
Table 1 Constituent ratio of four viruses
Virus
|
Cases of detection
|
n (%)
|
ADV
|
103209
|
13375 (13.0)
|
FLUA
|
96290
|
17509 (18.2)
|
FLUB
|
96290
|
2187 (2.3)
|
RSV
|
103209
|
7223 (7.0)
|
Any one of the above virus
|
103210
|
38355 (37.2)
|
ADV: adenovirus, FLUA: influenza A, FLUB: influenza B, RSV: respiratory syncytial virus
3. Viral infection at different ages
Among the 38355 children with positive viral infection, the difference among different age groups was statistically significant (χ2 =1280.7, p<0.001, see Table 2 for details).
Table 2 Virus infection in different age groups
Age
|
n (%)
|
<1 year
|
3684 (26.3)
|
1-3 years
|
13834 (35.0)
|
3-6 years
|
13554 (41.4)
|
> 6 years
|
7283 (43.0)
|
Total
|
38355 (37.2)
|
4. Viral infection in different seasons
The positive rates in spring, summer, autumn and winter were 19.8%, 18.7%, 30.2% and 47.1% respectively, with the highest in winter.
2. Detection of each virus
1.Positive rate of different age groups
The positive rates of four viruses in different age groups are shown in Table 3. Figure 1 showed that the positive rate of ADV is the highest in the 3-6-year-old group, the positive rates of FLUA and FLUB increase with the increase of age, and the positive rate of RSV is the highest in the < 1-year-old group.
Table 3 The positive rate of four viruses in different age groups
Virus Age
|
(n, %)
|
χ2
|
p value
|
|
ADV
|
13375 (13.0)
|
2601.2
|
<0.001
|
|
<1 year
|
523 (3.7)
|
|
|
|
1-3 years
|
3862 (9.8)
|
|
|
|
3-6 years
|
6107 (18.7)
|
|
|
|
> 6 years
|
2883 (17.0)
|
|
|
|
FLUA
|
17509 (18.2)
|
535.3
|
<0.001
|
|
<1 year
|
1658 (12.8)
|
|
|
|
1-3 years
|
6229 (16.8)
|
|
|
|
3-6 years
|
6135 (20.4)
|
|
|
|
> 6 years
|
3487 (21.6)
|
|
|
|
FLUB
|
2187 (2.3)
|
1869.3
|
<0.001
|
|
<1 year
|
79 (0.6)
|
|
|
|
1-3 years
|
329 (0.9)
|
|
|
|
3-6 years
|
707 (2.4)
|
|
|
|
> 6 years
|
1072 (6.6)
|
|
|
|
RSV
|
7223 (7.0)
|
2046.6
|
<0.001
|
|
<1 year
|
1481 (10.6)
|
|
|
|
1-3 years
|
4016 (10.2)
|
|
|
|
3-6 years
|
1534 (4.7)
|
|
|
|
> 6 years
|
192 (1.1)
|
|
|
|
ADV: adenovirus, FLUA: influenza A, FLUB: influenza B, RSV: respiratory syncytial virus
2. Positive rate in different seasons
The positive rates of four viruses in spring, summer, autumn and winter were 18.2%, 16.0%, 12.6% and 11.2% for ADV, 0.4%, 0.2%, 2.7% and 28.8% for FLUA, 0.2%, 0.1%, 0.0% and 3.6% for FLUB, 3.5%, 3.4%, 17.4% and 5.6% for RSV, respectively (Table 4). Figure 2 shows that the total detection rate is the highest in winter, ADV is the highest in spring, FLUA, FLUB is the highest in winter, RSV is the highest in autumn.
Table 4 Positive rates of four viruses in different seasons
Virus Season
|
(n, %)
|
χ2
|
p value
|
|
Four viruses
|
38355(37.2)
|
6459.1
|
<0.001
|
|
Spring
|
2958(19.8)
|
|
|
|
Summer
|
2117(18.7)
|
|
|
|
Autumn
|
5212(30.2)
|
|
|
|
Winter
|
28068(47.1)
|
|
|
|
ADV
|
13375(13.0)
|
629.2
|
<0.001
|
|
Spring
|
2726(18.2)
|
|
|
|
Summer
|
1811(16.0)
|
|
|
|
Autumn
|
2171(12.6)
|
|
|
|
Winter
|
6667(11.2)
|
|
|
|
Flu A
|
17509(18.2)
|
11820.4
|
<0.001
|
|
Spring
|
57(0.4)
|
|
|
|
Summer
|
21(0.2)
|
|
|
|
Autumn
|
275(2.7)
|
|
|
|
Winter
|
17156(28.8)
|
|
|
|
Flu B
|
2187(2.3)
|
1237.3
|
<0.001
|
|
Spring
|
28(0.2)
|
|
|
|
Summer
|
12(0.1)
|
|
|
|
Autumn
|
3(0.0)
|
|
|
|
Winter
|
2144(3.6)
|
|
|
|
RSV
|
7223(7.0)
|
3596.8
|
<0.001
|
|
Spring
|
518(3.5)
|
|
|
|
Summer
|
380(3.4)
|
|
|
|
Autumn
|
3010(17.4)
|
|
|
|
Winter
|
3315(5.6)
|
|
|
|
ADV: adenovirus, FLUA: influenza A, FLUB: influenza B, RSV: respiratory syncytial virus
3. Monthly positive detection of each virus
The positive rates of four viruses in 38355 were shown in Figure 3. It showed that the highest positive rate of ADV in May, FLUA in February, FLUB in March and RSV in December. At the same time, the overall positive rate was the highest in February.