Objective: To examine the reliability of "low risk" criteria (LRC) to exclude serious bacterial infection (SBI) in febrile neonates (≤ 28 days), according to age in weeks.
Design: Epidemiologic and clinical data and final diagnosis of all febrile neonates presenting to the ER from June 1997 through May 2006 were reviewed. Neonates who fulfilled specific low risk criteria for the presence of SBI were classified as LRC+. The prevalence of SBI and the percentage of LRC+ neonates who had SBI were calculated for each of the first 4 weeks of life.
Results: A total of 449 neonates were evaluated. Eighty seven (19.4%) neonates had an SBI. The prevalence of SBI among infants 3-7, 8-14, 15-21 and 22-28 days of age was 21.6%, 26.1%, 17.9% and 12.1% respectively (p=0.007 for linear trend after 2nd week of life). Of the 226 LRC+ neonates, 14 (6.2%) had an SBI, including 1 case of bacteremia and meningitis and 13 cases of urinary tract infection (UTI). The negative predictive value (NPV) of the LRC for SBI was 93.8% (95% CI: 90.1%-96.4%). The prevalence of SBI among LRC+ infants 3-7, 8-14, 15-21 and 22-28 days of age was similar, with rates of 15%, 6.3%, 3.0% and 6.7%, respectively.
Conclusion: "low risk" criteria are not sufficiently reliable to exclude the presence of SBI, including bacteremia and meningitis in febrile neonates of all ages. All febrile neonates should therefore be hospitalized, undergo a full "sepsis evaluation" and receive empiric intravenous antibiotic therapy.