BACTERIAL MENINGITIS: A DIAGNOSTIC APPROACH

Over a thirteen months period, 456 patients clinically suspected of having bacterial meningitis were investigated. Cerebrospinal fluid (CSF) specimens were examined by Gram’s stain, white cell (WBC) counts and culture techniques. Gram’s stain and cultures of CSF (232) with a cell count of less than 10 cells/mm3 were consistently negative. However, of the CSF specimens (88) with cell counts greater than 100/mm3, 28 (6.7%) and 23 (5.2%) of the specimens were positive by cultures and Gram’s stain respectively. A total of 31 isolates were identified by culture. Streptococcus pneumoniae (22.4%), Escherichia coli (16%), and Coagulase negative Staphylococci (16%) were the predominant organisms, followed by Haemophilus influenzae (6.4%) and Neisseria meningitidis (2.6%). Thus it was concluded that Gram’s stain and perhaps culture of CSF with cell counts of less than 10/mm3 are of no practical diagnostic significance and may be eliminated as routine procedures. The gold standard for the diagnosis of bacterial meningitis is raised WBC cell count ( 100/mm3), positive Gram’s smear and/ or culture of CSF specimen