Diagnosis of bacterial meningitis in previously treated children.

We reviewed the charts of 115 children with the clinical diagnosis of bacterial meningitis admitted to our hospital over a period of eight years. Of these, 47 patients had received antimicrobial agents before hospitalization and eight (17%) of them had negative cerebrospinal fluid (CSF) cultures. These eight children, however, had CSF features suggestive of bacterial meningitis. We conclude that prior antimicrobial therapy does not alter the chemical properties of CSF, the response to pharmacologic agents, or the ultimate outcome, even though previously treated children may have lower rates of positive CSF and blood cultures.