Risk of serious bacterial infection in children with fever without a source in the post-Haemophilus influenzae era when antibiotics are reserved for culture-proven bacteremia

OBJECTIVE: To determine the rate of serious bacterial infection in children aged 2 to 36 months with fever without a source in the post-Haemophilus influenzae era, when antibiotic therapy is reserved until blood culture results turn positive. DESIGN AND SETTING: Retrospective review of emergency department, urgent care center, and hospital medical records from an urban children's hospital. PARTICIPANTS: Eligible participants were identified from hospital medical record and microbiology laboratory databases. Immunocompetent individuals aged 2 to 36 months with fever without a source were eligible for enrollment. Exclusion criteria were temperature less than 39.0 degrees C, identifiable focus of infection, current or recent antibiotic use, and hospital admission. INTERVENTIONS AND OUTCOME MEASURES: Enrolled participants were assigned to group 1 (blood culture obtained) or group 2 (no blood culture) and did not receive empiric antibiotic treatment in the emergency department, in the urgent care center, or for home use. Demographic and outcome data were collected on all enrolled patients. RESULTS: During the study, 9241 febrile children were identified; 2641 (29%) met the enrollment criteria. Blood cultures (group 1) were performed on 1202 patients (46%), and 37 (3%) had culture-proven occult bacteremia (95% confidence interval, 2.2%-4.2%). Streptococcus pneumoniae was the most prevalent organism (84%). The mean +/- SD time for reporting a positive blood culture finding was 17.5 +/- 8.5 hours. Two patients (0.08%; 95% confidence interval, 0.009%-0.27%) developed serious bacterial infection, and both recovered completely. CONCLUSION: Reserving antibiotic therapy for culture-proven occult bacteremia was not associated with increased risk of developing serious bacterial infection compared with previously published data.