Acute bacterial meningitis. Cerebrospinal fluid differential count

A retrospective analysis of 112 cases of pediatric bacterial meningitis over a 3-year period was performed to determine the rate of cerebrospinal fluid (CSF) lymphocytosis at initial evaluation. Of 14 neonates and 98 children older than 1 month of age not receiving preadmission antibiotic therapy, only one instance of CSF lymphocytosis occurred. This patient's CSF exhibited pleocytosis, hypoglycorrhachia, abnormally elevated protein content, and organisms visualized on gram stain smear. In children with bacterial meningitis not receiving antibiotic therapy at the time of evaluation, CSF differential cell count with relative lymphocytosis is rare.