Serious bacterial infections in young children with fever without source after discharge from emergency department: A National Health Insurance database cohort study

Background: Well-appearing febrile young children discharged from the emergency department (ED) after medical assessment are still at risk for serious bacterial infections (SBI). The incidence of SBI and the effectiveness of laboratory tests in the pneumococcal conjugate vaccine era remain unknown. Methods: We conducted a study using Taiwan's National Health Insurance claims data from 2004 to 2014. Children aged 2–24 months discharged from the ED with a diagnosis compatible with fever without source (FWS) were enrolled. Results: The study identified 431,884 children from the ED with FWS. 13.53% of the children had revisits, 8.62% needed hospitalization and 1.57% developed SBI. Younger children had a higher SBI rate, but a lower revisit rate. The revisit rate was 12.22% for children aged 2–6 months, 13.61% for children aged 7–12 months and 13.77% for children aged 13–24 months (p < 0.0001). The SBI rate was 4.44% for children aged 2–6 months, 1.85% for children aged 2–6 months and 0.96% for children aged 13–24 months (p < 0.0001). Children with hemogram tests, compared to those without, had a higher revisit rate (16.30% vs. 13.15%, p < 0.0001), and a higher SBI rate in the children aged 13–24 months (1.30% vs. 0.92%, p < 0.0001); furthermore, children with urinalysis had a significantly higher revisit rate (14.42% vs. 13.24%, p < 0.0001) and higher SBI rate (2.10% vs. 1.40%, p < 0.0001). Conclusion: Children with FWS aged 2–24 months who were discharged from ED after blood test and urinalysis were still at risk for SBI, especially those aged 2–6 months.