Incidence, Characteristics, and Outcomes of Clinically Undetected Bacteremia in Children Discharged Home From the Emergency Department

Background: Despite a recent decline in the rates of invasive infections, bacteremia in young children remains a significant challenge. We aimed to describe patient characteristics, microbial etiology, and outcomes of bacteremic, well-appearing children 3-36 months of age who were discharged home from the pediatric emergency department (PED) on their index visit. Methods: A retrospective cohort study in the PED of a tertiary children's hospital from 1 June 2015 until 30 June 2021. We included all well appearing, immunocompetent infants 3-36 months old evaluated for fever and discharged home from the PED after a blood culture was drawn. We extracted demographic, clinical and laboratory data from the patient's electronic medical records for the index visit and subsequent encounters. Results: During the study period, 17,114 children evaluated for fever met the inclusion criteria. Seventy-two patients (0.42%) had positive cultures for known pathogens. Thirty-six (50%) were male and 36 (50%) younger than 1 year. The most common isolates were S. pneumonia 26%. (n = 19), K. Kingae 25%. (n = 18) and Salmonella spp. 13.9% (n = 10). Sixty patients (85.7%) were recalled to the ED or had a scheduled appointment, 10 (14.3%) returned spontaneously and two were followed up by phone. The median time between visits was 28.7 hours (IQR 19.1-41.1). One patient was admitted to intensive care during the course of hospitalization. There were no deaths. Conclusion: The rate of undetected true bacteremia in our study was low and our data suggest that significant clinical deterioration during the first 24 hours is rare.