P2C248: Prevalence of CNS Infection in Well Appearing Febrile Infants at 22-28 Days of Life

Background: Neonatal sepsis is a major cause of morbidity and mortality among newborn infants and is a serious heterogenous condition impacted by multiple factors. The most recent American Academy of Pediatrics guidelines for the management of febrile infants recommend performing lumbar puncture (LP) in all febrile neonates less than 22 days of life. For neonates at 22-28 days of life, the guidelines recommend LP if inflammatory marker levels and /or urine analysis are abnormal. However, in well-appearing febrile infants aged 22-28 days with normal inflammatory marker levels the guidelines leave the decision for LP to clinician discretion. Thus, our study aimed to identify the percentage of well-appearing febrile infants aged 22-28 days receiving LP and the percentage with confirmed central nervous system infection (CNS).

Methods: We performed a retrospective chart review of well-appearing febrile infants at 22-28 days of age admitted to our hospital during a ten year period. We obtained patient characteristics, clinical presentation, and diagnostic testing results.

Results: Of 40 patients, 60% were males, median gestational age (GA) was 35 weeks, consisting of 26 (65%) infants receiving LP, and 14 (35%) who did not. Patients receiving LP presented with significantly higher temperature (p < 0.001) and elevated absolute neutrophilic count (ANC) (p=0.04) compared to those without LP. Out of the 26 patients who received LP, 33% were found to have enterovirus CNS infection, with no identified cases of bacterial or herpes meningitis. Out of the 14 patients who did not receive LP, 64% had at least one identifiable non-CNS infection source.

Conclusion: Bacterial and herpes meningitis are uncommon causes of fever in well-appearing febrile infants. Physicians should take into consideration the clinical assessment and inflammatory marker levels before deciding to perform a LP in well-appearing newborns 22-28 days of life.