Table 1  A comparison of the characteristics between children with a positive for MP-specific IgM titer at the time of admission and those with a negative MP-specific IgM titer at the time of admission due to MP pneumonia

n

118

37

155

NA

Male, n (%)

55/118 (46.6)

21/37 (56.8)

76/155 (49.0)

0.281

Age at diagnosis of MP pneumonia, years

5.8 ± 3.5

6.9 ± 4.8

6.0 ± 3.8

0.176

Duration between symptom onset and admission, days

7.4 ± 3.6

4.0 ± 3.4

6.6 ± 3.8

< 0.001

Total duration of fever during the illness, days

7.6 ± 7.1

5.0 ± 4.1

7.0 ± 6.6

0.021

Total hospitalization duration, days

9.9 ± 5.5

7.9 ± 4.6

9.5 ± 5.4

0.047

Development of any extra-pulmonary symptoms, n (%)

34/118 (28.8)

2/37 (5.4)

36/155 (23.2)

0.003

Pleural effusion, yes, n (%)

21/118 (17.8)

4/37 (10.8)

25/155 (16.1)

0.313

Hemoptysis, yes, n (%)

1/118 (0.8)

3/37 (8.1)

0.015

Oxygen need, yes, n (%)

10/118 (8.5)

0/37 (0.0)

10/155 (6.5)

0.067

Respiratory virus co-infection, yes, n (%)

53/118 (44.9)

12/37 (32.4)

65/155 (41.9)

0.179

Positive results on pneumobacter PCR, n (%)

21/61 (34.4)

6/12 (50.0)

27/73 (337.0)

0.307

Respiratory virus co-infection or positive results on pneumobacter PCR, n (%)

63/118 (53.4)

15/37 (40.5)

77/155 (49.7)

0.173

Macrolide-resistant MP

92/110 (83.6)

25/36 (69.4)

117/146 (80.1)

0.403

Response to stepwise treatment for MP pneumonia, n (%)

0.042

 Good response

40/118 (33.9)

19/37 (51.4)

59/155 (38.1)

 Slow response

59/118 (50.0)

18/37 (48.6)

77/155 (49.7)

 No response

14/118 (11.9)

0/37 (0.0)

14/155 (9.0)

 Progression

5/118 (4.2)

0/37 (0.0)

5/155 (3.2)

Trend P

0.007

Severity of pneumonia based on chest radiography

0.149

 Mild

12/118 (10.2)

7/37 (18.9)

19/155 (12.3)

 Moderate

75/118 (63.6)

25/37 (67.6)

100/155 (64.5)

 Severe

31/118 (26.3%)

5/37 (13.5%)

36/155 (23.2)