Bacterial meningitis carries a high mortality and morbidity if untreated or treated late. The success of parenteral antibiotic therapy depends on early diagnosis. Although cerebral spinal fluid (CSF) studies allow early presumptive diagnosis prior to initiation of treatment, broad spectrum parenteral antibiotics are currently administered, regardless of initial CSF results, if a bacterial cause is suspected, with the inherent risk of drug side effects and induction of bacterial resistance. CSF culture allows bacteriological diagnosis, but results are not immediate. Rapid identification of the offending organism by Gram's stain characteristics or bacterial antigen detection testing (BADT) allows chemoprophylaxis of contacts whenever indicated.The value of these two tests in CSF analysis has been contradictory in the literature, especially in patients with meningitis who received antibiotic therapy before the lumbar puncture was carried out. [1][2][3][4][5][6][7][8][9][10] The clinical usefulness of these tests should, therefore, be reassessed in light of the local epidemiology, immunization programs (Haemophilus influenzae type b [Hib] and Neisseria meningitidis) and the cost containment imperatives that all health care systems are currently encountering.We undertook to assess the clinical usefulness of CSF BADT and Gram's stain studies in children diagnosed as having meningitis in our institution, focusing on the bacterial cases and on all those who had been treated with antibiotics prior to lumbar puncture.
MethodsAll cases of meningitis diagnosed in children under 14 years of age in our institution between January 1983 and June 1995 were analyzed. Patients were considered to have bacterial meningitis if the clinical presentation was suggestive and if parenteral antibiotic therapy for bacterial meningitis was given for at least seven days, with either a positive CSF culture or BADT, or if organisms were seen on Gram's stain, or in the presence of meningococcal septicemia with purpura and CSF. pleocytosis in the absence of a positive CSF culture.All medical records were reviewed and data collected included age, sex, antibiotic therapy before lumbar puncture, results of CSF analysis (total white blood cells [WBC] and differential, protein, glucose, Gram's stain, culture and BADT). CSF pleocytosis was defined as CSF WBC over 6 x 10 -6 /L (6 WBC/mm 3 ). BADT was carried out with Wellcogen ® Bacterial Antigen Kit, Murex Diagnostics Limited, Dartford, England. This kit uses rapid qualitative latex agglutination technique to detect specific polysaccharide surface antigens for Haemophilus influenzae type b (Hib), Streptococcus pneumoniae (Strep. pneumoniae), Escherichia coli (E. coli) K1, group B streptococcus and Neisseria meningitidis (N meningitidis) groups A, B, C, Y and W135 antigens.
ResultsDuring the study period, a total of 98 cases of meningitis were diagnosed: 63 were aseptic (64.3%) and 35 bacterial (35.7%). A total of 20 children (20.4%) had received antibiotics prior to diagnosis. Gram's stain showed org...