Table 1 Clinical characteristics of pediatric inpatients with pneumonia prior to and during the COVID-19 pandemic

Number of cases, n(%)

825(100.0)

213(100.0)

Age, median(IQR), m

53(26.0–84.0)

26(9.0–52.0)

0.000*

Gender, n(%)

0.240

 Male

451(54.7)

126(59.2)

 Female

374(45.3)

87(40.8)

Hospital stay, median(IQR), d

6(5.0–8.0)

7(5.0–10.0)

0.000*

Season of hospitalization, n(%)

0.173

 Spring(Mar.-May.)

376(45.6)

86(40.4)

 Summer(Jun.-Aug.)

449(54.4)

127(59.6)

Severity, n(%)

0.242

 Mild

782(94.8)

206(96.7)

 Severe

43(5.2)

7(3.3)

Bacterial infections, n(%)

52(6.3)

21(9.9)

0.070

 Moraxella catarrhalis

4(0.5)

2(0.9)

 Haemophilus influenzae

21(2.5)

2(0.9)

 Streptococcus pneumoniae

11(1.3)

4(1.9)

 Staphylococcus

11(1.3)

5(2.3)

 Acinetobacter baumannii

3(0.4)

1(0.5)

 Pseudomonas aeruginosa

2(0.2)

3(1.4)

 Klebsiella pneumoniae

0(0.0)

3(1.4)

 Enterobacter cloacae

0(0.0)

1(0.5)

Viral infections, n(%)

143(17.3)

15(7.0)

0.000*

 RSV

5(0.6)

0(0.0)

 ADV

34(4.1)

2(0.9)

 IV

55(6.7)

4(1.9)

 PIV

37(4.5)

2(0.9)

 Coxsackie virus

12(1.5)

7(3.3)

Mp infection, n(%)

470(57.0)

83(39.0)

0.000*

Mixed infections, n(%)

134(16.2)

15(7.0)

0.001*

 Bacteria + Bacteria

3(0.4)

1(0.5)

 Bacteria + Mp

17(2.1)

2(0.9)

 Bacteria + Viruses

3(0.4)

0(0.0)

 Bacteria + Mp + Viruses

5(0.6)

2(0.9)

 Viruses + Mp

106(12.8)

9(4.2)

 Viruses + Viruses

0(0.0)

1(0.5)

Serum sIgE(IU/ml), n(%)

 House dust mite

0.000*

  < 0.35

613(74.3)

86(40.4)

  ≥ 0.35

109(13.2)

38(17.8)

 Milk

0.105

  < 0.35

571(69.2)

90(42.3)

  ≥ 0.35

151(18.3)

34(16.0)

 Egg white

0.192

  < 0.35

646(78.3)

106(49.8)

  ≥ 0.35

76(9.2)

18(8.5)

 Shrimp

0.000*

  < 0.35

713(86.4)

115(54.0)

  ≥ 0.35

9(1.1)

9(4.2)

 Crab

0.000*

  < 0.35

715(86.7)

115(54.0)

  ≥ 0.35

7(0.8)

9(4.2)

Micronutrient levels

 Vitamin A(umol/l)

0.137

  < 0.52

13(1.6)

4(1.9)

  0.52–2.2

466(56.5)

49(23.0)

 Vitamin B1(nmol/l )

0.939

  < 50

21(2.5)

3(1.4)

  50–150

458(55.5)

50(23.5)

 Vitamin B2(ug/l)

0.044*

  < 200

25(3.0)

7(3.3)

  ≥ 200

454(55.0)

46(21.6)

 Vitamin B6(umol/l)

0.000*

  < 14.6

1(0.1)

4(1.9)

  14.6–72.9

478(57.9)

49(23.0)

 Vitamin C(umol/l)

0.000*

  < 34

48(5.8)

17(8.0)

  34–114

431(52.2)

36(16.9)

 Serum 25(OH)D(nmol/l)

0.000*

  < 50

0(0.0)

9(4.2)

  ≥ 50

478(57.9)

44(20.7)

 Zn(umol/l)

0.756

  < 9.2

86(10.4)

10(4.7)

  9.2–22.9

348(42.2)

36(16.9)

 Ca(mmol/l)

0.100

  < 2.0

30(3.6)

0(0.0)

  2.0-2.74

404(49.0)

46(21.6)