Cerebrospinal Fluid Profiles of Infants ≤60 Days of Age With Bacterial Meningitis

OBJECTIVES: We aimed to describe the cerebrospinal fluid (CSF) profiles of infants ≤60 days old with bacterial meningitis and the characteristics of infants with bacterial meningitis who did not have CSF abnormalities. METHODS: We included infants ≤60 days old with culture-positive bacterial meningitis who were evaluated in the emergency departments of 11 children’s hospitals between July 1, 2011, and June 30, 2016. From medical records, we abstracted clinical and laboratory data. For infants with traumatic lumbar punctures (CSF red blood cell count of ≥10 000 cells per mm3), we used a red blood cell count/white blood cell (WBC) count correction factor of 1000:1 to determine the corrected CSF WBC count. We calculated the sensitivity for bacterial meningitis of a CSF Gram-stain and corrected CSF pleocytosis (≥16 WBCs per mm3 for infants ≤28 days old and ≥10 WBCs per mm3 for infants 29–60 days old). RESULTS: Among 66 infants with bacterial meningitis, the sensitivity of a CSF Gram-stain was 71.9% (95% confidence interval [CI]: 59.2–82.4), and the sensitivity of corrected CSF pleocytosis was 80.3% (95% CI: 68.7–89.1). The sensitivity of combining positive Gram-stain results with corrected CSF pleocytosis was 86.4% (95% CI: 75.7–93.6). Of 9 infants with meningitis who had a negative Gram-stain result and no corrected CSF pleocytosis, 8 (88.9%) had either an abnormal peripheral WBC count (>15 000 or <5000 cells per μL) or bandemia >10%. CONCLUSIONS: Most infants ≤60 days old with bacterial meningitis have CSF pleocytosis or a positive Gram-stain result. Infants with no CSF pleocytosis and a negative Gram-stain result are unlikely to have bacterial meningitis in the absence of other laboratory abnormalities.