BLOOD CULTURE RESULTS AS DETERMINANTS IN THE ORGANISM IDENTIFICATION OF BACTERIAL-MENINGITIS

The diagnosis of bacterial meningitis depends on a lumbar puncture (LP). Sometimes, antibiotics are administered before a LP that is delayed owing to prior need for computerized tomography (CT) scan, technical problems, inability to obtain consent, or an unstable patient. We examined the accuracy of blood culture, cerebrospinal fluid (CSF) Gram's stain, and antigen detection by latex for organism identification of meningitis. All patients admitted to the Children's Hospital of Buffalo between January 1, 1984 and December 31, 1989 and having a CSF culture diagnosis of bacterial meningitis had their charts retrospectively reviewed. Patients excluded from the study were those with neural tube defects or CSF catheters, those admitted directly to the Intensive Care Nursery (ICN), those whose positive CSF cultures were determined to be a contaminant, those whose medical records were not found, or those older than 16 years. We analyzed a total of 178 patients with positive CSF cultures and the confirmed diagnosis of bacterial meningitis. Of 169 patients who had a blood culture performed, 86% had the organism responsible for meningitis recovered by this test, with the highest yield of 91% occurring in the 2.5-month to 24-month age group. Blood culture identified the bacteria in 94% of those patients with Haemophilus influenzae meningitis, and this yield increased to 100% when patients who had been pretreated with antibiotics were excluded. The combination of blood culture, CSF Gram's stain, and/or latex agglutination identified the causative bacteria in 92% of patients with meningitis. Blood culture, CSF Gram's stain, and latex agglutination are useful in identifying the organism causing pediatric meningitis. Our findings indicate that, in cases where the antibiotic is administered prior to LP, the information from these tests can help in subsequent organism identification.