Blood cultures in hospitalized children.

The results of 2439 blood cultures that were taken in an acute children's hospital over a two-year period were reviewed. Three hundred and twenty-two organisms were cultured from 310 patients. One hundred and thirty-five (5.5%) isolates were considered to be pathogenic and 187 (7.7%) isolates were considered to be contaminants. Coagulase-positive staphylococci and enteric Gram-negative organisms were the isolates of which the significance was most difficult to determine. Community-acquired bacteraemia that affected children of less than five years of age was caused by Haemophilus influenzae in 65% of cases. Staphylococcus aureus was the major pathogen in older children. In 20% of cases, antimicrobial agents were commenced or changed after blood culture results. Delayed or inappropriate therapy was significantly more common in patients without an apparent focus of infection. The results of our study suggest that narrow spectrum antimicrobial agents can be used as appropriate empiric therapy for unlocalized infections in previously-well children. In children of between three months and five years of age, treatment should be directed against Haem. influenzae and Streptococcus pneumoniae, and in children of over five years of age, antistaphylococcal therapy should also be included.