Investigators at multiple institutions conducted a cross-sectional study to assess the prevalence and characteristics of pneumococcal pneumonia (PP) before and after the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in 2010. Children were eligible if they were ≤18 years old and had PP managed as an inpatient at 1 of 8 participating US children’s hospitals from 2006 to 2014. PP was defined as the isolation of Streptococcus pneumoniae from blood, pleural fluid, lung abscess, or lung tissue, with clinical presentation and radiographic changes consistent with pneumonia. PP was categorized as complicated if there was pulmonary consolidation plus a large pleural effusion (>10-mm rim or ≥25% of the hemithorax opacified), loculated pleural fluid, parapneumonic empyema, necrotizing pneumonia, or lung abscess. Demographic, clinical, and S pneumoniae serotype data were obtained from the medical chart. Investigators compared annual hospitalization rates for all PP, complicated PP, and serotype-specific PP before (2006–2009) and after (2011–2014) PCV13 introduction.
There were 377 patients with PP included in the analysis. The hospitalization rate for all PP decreased from 53.6 per 100,000 admissions before PCV13 to 23.3 per 100,000 admissions after PCV13 (P < .0001). Hospitalization rates for complicated PP also decreased significantly. Comorbid conditions were more common among children with uncomplicated pneumonia than complicated pneumonia (52.2% vs 22.5%, respectively; P< .001). The need for intensive care and invasive procedures did not change after the introduction of PCV13.
A total of 364 of 377 isolates (96.6%) were available for serotyping and antibiotic susceptibility testing. Although there was a significant decrease in hospitalization rates for PP caused by PCV13 serotypes, they still accounted for 70% of PP cases in the post-PCV13 era (2011–2014). There was no increase in the hospitalization rate of PP caused by non-PCV13 serotypes (4.3 per 100,000 admissions before PCV13 vs 6.7 per 100,000 admissions after PCV13; P = .1). The proportion of isolates susceptible to penicillin increased from 90.8% in 2006–2009 to 97% in 2011–2014 (P = .05). A lower proportion of isolates associated with complicated (91.3%) versus uncomplicated (98.2%) PP were susceptible to penicillin (P = .015).
The investigators conclude that hospitalization rates for PP have decreased since the introduction of PCV-13.
Dr Brady has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
The results of the current study agree with those of previous studies, 1,2 which demonstrated a significant decline in the incidence of invasive pneumococcal disease (IPD) among children after the introduction of PCV13. These observations contrast to those for the incidence of pneumococcal meningitis, which, as of 2013, had remained unchanged among these same 8 US children’s hospitals. (See AAP Grand Rounds 2015;34:65.3 )...