2015 HSC Section 1 Book of Articles

TABLE 1 Number of Hospitalizations and Incidence of Pneumonia, Sinusitis, Empyema, Pyelonephritis, Asthma and Obstructive Bronchitis, RSV Infection, and Viral Pneumonia in Children 0 to , 18 y Before and After Sequential PCV7 and PCV13 Introduction in Stockholm Diagnosis No. of Cases IncidenceRateper100 000 Person-Years RR (95% CI) P

Before July 2003 – June 2007

After July 2008 – June 2012

Before July 2003 – June 2007

After July 2008 – June 2012

Pneumonia 0 – , 2 y

, .001

914 687 604

836 694 683

450 250

366 212

0.81 (0.74 – 0.89) 0.85 (0.76 – 0.94) 1.10 (0.99 – 1.23) 0.34 (0.25 – 0.47) 0.72 (0.51 – 1.02) 1.16 (0.87 – 1.56) 1.78 (0.55 – 6.63) 1.68 (0.52 – 6.26) 1.68 (0.80 – 3.53) 1.13 (1.01 – 1.25) 1.06 (0.84 – 1.35) 1.36 (1.11 – 1.66) 1.04 (0.98 – 1.10) 1.07 (0.97 – 1.18) 0.94 (0.81 – 1.10) 1.37 (1.29 – 1.46) 1.98 (1.46 – 2.69) 3.89 (1.66 – 10.56) 1.46 (1.08 – 1.97) 1.20 (0.81 – 1.78) 2.35 (1.46 – 3.78)

2 – , 5 y 5 – , 18 y

.002

51

56

.09

Sinusitis

0 – , 2 y 2 – , 5 y 5 – , 18 y

, .001

142

55 60 98 10 10 19

70 25

24 18

70 82

.06 .31

7

8

Empyema 0 – , 2 y

5 5

2.5 1.8 0.9

4.4 3.1 1.6

.42 .49 .17

2 – , 5 y 5 – , 18 y

11

Pyelonephritis 0 – , 2 y

598 123 167

757 156 233

294

331

.03 .61

2 – , 5 y 5 – , 18 y

45 14

48 19

.002

Asthma and obstructive bronchitis 0 – , 2 y

.21 .20 .44

2136

2493

1051

1090

2 – , 5 y 5 – , 18 y

709 334

902 323

258

275

28

27

RSV infection 0 – , 2 y

, .001 , .001 , .001

1711

2647

842

1158

2 – , 5 y 5 – , 18 y

58

137

21

42

7

28

0.6

2.3

Viral pneumonia 0 – , 2 y

70 42 24

115

34 15

50 18

.01 .37

2 – , 5 y 5 – , 18 y

60 58

, .001

2.0

4.8

(in 2005) with 50 cases after vaccine introduction (in 2009), no differences were observed in frequency of chest radiographs on admission (100% in 2005, 98% in 2009). Chronic conditions (mainly asthma, prematurity, or neu- rologic disease) were found in 36% of children in 2005 and 31% in 2009 ( P = .82). The clinical severity of pneumonia, measured using mean C-reactive pro- tein, oxygen saturation, and need for oxygen or intensive care, was compa- rable in 2005 and in 2009 (data not shown). Empyema For children , 2 years old there was a nonsigni fi cant increased incidence of hospitalization for empyema in the period after compared with the period before PCV7 and PCV13 vaccination (4.4 vs 2.5 per 100 000 person-years;

RR = 1.78; 95% CI, 0.55 – 6.63; P = .42) (Table 1).

and viral pneumonia increased sig- ni fi cantly in children , 2 years old between the prevaccination and post- vaccination periods (RR = 1.37; 95% CI, 1.29 – 1.46; P , .001 and RR = 1.46; 95% CI, 1.08 – 1.97; P = .01, respectively) (Table 1). DISCUSSION To our knowledge this is the fi rst study showing that introduction of PCV7 and PCV13 in the childhood vaccination program signi fi cantly reduces hospi- talizations for sinusitis in children , 5 years of age. We also found a signi fi - cant reduction in hospitalization rates for pneumonia in children , 5 years old. However, there was an increase in empyema in children , 2 years of age in the postvaccination compared with the prevaccination period, but this was not statistically signi fi cant.

Hospitalization for Control Diagnosis

Pyelonephritis was used as an indica- tor disease for general hospitalization trends during the study period. There was a slight increase in hospitalizations during the study period in the age group 0 to , 2 years but not among children aged 2 to , 5 years (Table 1). However, in the time trend analysis (Fig 1) the month-to-month incidence remained stable in the prevaccination and post- vaccination period for both age groups (Fig 1 and Table 2). The incidence of hospitalizations for asthma and obstructive bronchitis remained stable during the study pe- riod (Table 1). However, the incidence of hospitalization for RSV infections

PEDIATRICS Volume 134, Number 6, December 2014

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