An HSV infection was uncommon in young infants evaluated for CNS infection, particularly in the second month of life. Evidence-based approaches to the evaluation for HSV in young infants are needed.

The age-specific CSF WBC count, protein concentration, and glucose concentration reference values identified in this large, multicenter cohort of infants can be used to interpret the results of lumbar puncture in infants ≤60 days of age.

Point-of-care ultrasonography is increasingly being used to facilitate accurate and timely diagnoses and to guide procedures. It is important for pediatric emergency physicians caring for patients in the emergency department to receive adequate and continued point-of-care ultrasonography training for those indications used in their practice setting. Emergency departments should have credentialing and quality assurance programs. Pediatric emergency medicine fellowships should provide appropriate training to physician trainees. Hospitals should provide privileges to physicians who demonstrate competency in point-of-care ultrasonography. Ongoing research will provide the necessary measures to define the optimal training and competency assessment standards. Requirements for credentialing and hospital privileges will vary and will be specific to individual departments and hospitals. As more physicians are trained and more research is completed, there should be one national standard for credentialing and privileging in point-of-care ultrasonography for pediatric emergency physicians.

Study Objective To determine the optimal correction factor for cerebrospinal fluid (CSF) white blood cell (WBC) counts in infants with traumatic lumbar punctures (LPs). Methods We performed a secondary analysis of a retrospective cohort of infants ≤ 60–days-old with a traumatic LP [CSF red blood cell (RBC) count ≥ 10,000 cells/mm3] at 20 participating centers. CSF pleocytosis was defined as a CSF WBC count ≥ 20 cells/mm3 for infants ≤ 28 days, ≥ 10 cells/mm3 for infants 29–60 day and bacterial meningitis as growth of pathogenic bacteria from CSF culture. Using linear regression, we derived a CSF WBC correction factor and compared the uncorrected to the corrected CSF WBC count for the detection of bacterial meningitis. Results Of the eligible 20,319 LPs, 2,880 (14%) were traumatic of whom 33 (1.1%) had bacterial meningitis. The derived CSF RBCs:WBCs ratio was 877:1 [95% confidence interval (CI) 805–961:1]. Compared with the uncorrected CSF WBC count, the corrected CSF WBC count had lower sensitivity for bacterial meningitis [88% uncorrected vs. 67% corrected; difference 21%, 95% CI 10–37%] but resulted in fewer infants with CSF pleocytosis [78% uncorrected vs. 33% corrected; difference 45%, 95% CI 43–47%]. CSF WBC count correction resulted in 7 additional infants with bacterial meningitis being misclassified as not having CSF pleocytosis; only one of these infants was > 28-days-old. Conclusion Correction of the CSF WBC count substantially reduced the number of infants with CSF pleocytosis while misclassifying only one infant with bacterial meningitis 29 to 60 days of age.