Clinical question: Have the causative organisms in pediatric bacteremia changed over time concurrent with introduction of the pneumococcal conjugate vaccine?
Background: Previous research has shown introduction of polyvalent pneumococcal conjugate vaccine led to changes in the organisms causing meningitis and otitis media, and patterns of nasopharyngeal colonization. Pneumococcus, historically, was a common cause of bacteremia. The availability of pneumococcal conjugate vaccine may have changed the organisms causing bacteremia in children.
Study design: Retrospective chart review and time series.
Setting: Children presenting to the ED of Alder Hey Children’s Hospital in Liverpool, England, from 2001 to 2011.
Synopsis: Five hundred seventy-five episodes of bacteremia were found in 525 children. Infants most commonly had E. coli and Group B streptococcal infections; children over age five most commonly had S. aureus. The introduction of the pneumococcal conjugate vaccine decreased pneumococcal bacteremia by 49% over the study period. This decrease was accompanied by an increase in Gram-negative bacteremia. Susceptibility to empiric antibiotics (third-generation cephalosporins) dropped from 96% to 83%. Over the study period, more children presented with central venous lines, which was felt to be due to increasing outpatient use of total parenteral nutrition (TPN).
Bottom line: Vaccination against pneumococcus is changing the microbiology of pediatric bacteremia, with fewer vaccine-preventable Gram-positive infections and more Gram-negative infections. This increases the likelihood of resistance to third-generation cephalosporins as empiric antibiotic.
Citation: Irwin AD, Drew RJ, Marshall P, et al. Etiology of childhood bacteremia and timely antibiotics administration in the emergency department. Pediatrics. 2015;135(4): 635-642.