Bacterial meningitis in the absence of CSF pleocytosis.

Two cases of acute bacterial meningitis occurred with an absent CSF WBC response. To determine the incidence and clinical characteristics of such patients, 50 consecutive cases of meningitis were reviewed retrospectively. In addition to the two initially noted cases, five additional cases were found. In the seven cases, there were six or fewer cells, but bacteria were detected in the CSF. A distinctive clinical and laboratory syndrome emerged. All seven patients were either old or had Hodgkin's disease or severe alcoholism. All patients had evidence of an overwhelming infection with confusion or nuchal rigidity. As compared with the remaining 45 patients with meningitis and CSF pleocytosis, no fever (less than 38 degrees C), a lower peripheral WBC count, and near-normal CSF glucose and protein concentrations were common. Organisms involved were EScherichia coli in three patients, Pneumococcus in three patients, and mixed anaerobes in patient. A fatal outcome ensued in six of seven patients. Despite the correct choice of an antibacterial agent, doses were late and suboptimal for meningitis. This syndrome is surprisingly common in host-defective cases, has an ominous prognosis, and must be treated expectantly with antimicrobial agents that enter the CSF.