Blood Culture in Evaluation of Pediatric Community-Acquired Pneumonia: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE: Current guidelines strongly recommend collection of blood cultures (BCs) in children requiring hospitalization for presumed moderate to severe bacterial community-acquired pneumonia (CAP). Our objective was to systematically review the international pediatric literature to evaluate how often BCs are positive in hospitalized children with CAP, identify the most commonly isolated pathogens, and determine the impact of positive BCs on clinical management.

METHODS: We identified articles in PubMed and Scopus published from January 1970 through December 2013 that addressed BCs in children with CAP. We extracted total number of BCs collected and prevalence of positive BCs and used meta-regression to evaluate whether subgroups had any impact on prevalence.

RESULTS: Meta-analysis showed that the overall prevalence of positive BCs was 5.14% (95% confidence interval 3.61-7.28). Studies focusing on severe CAP had a significant effect on prevalence (P=.008), at 9.89% (95% CI 6.79-14.19) compared with 4.17% (95% confidence interval 2.79-6.18) for studies not focusing on severe CAP. The most commonly isolated organisms were Streptococcus pneumoniae (76.7%) followed by Haemophilus influenzae (3.1%) and Staphylococcus aureus (2.1%). Contaminants accounted for 14.7%. Only 3 studies reported on BC-driven change in management, with contrasting findings.

CONCLUSIONS: BCs in pediatric CAP identified organisms in only a small percentage of patients, predominantly S. pneumoniae. False-positive BC rates can be substantial. The 3 studies that examined BC-driven changes in management had conflicting results. This systematic review was limited by heterogeneous case definitions, which may overestimate the true prevalence of positive BCs in hospitalized children.