Evaluation of Cerebrospinal Fluid Analysis in Bacterial and Viral Meningitis at National Hospital Abuja, North Central Nigeria

Lumbar puncture and cerebrospinal fluid analysis remain the cornerstone of laboratory diagnosis of meningitis, enabling differentiation between bacterial and viral aetiologies and guiding appropriate antimicrobial therapy. This study evaluated CSF parameters in patients diagnosed with bacterial and viral meningitis at National Hospital Abuja, North Central Nigeria. A retrospective cross-sectional study reviewed laboratory records and clinical data of 180 patients with confirmed meningitis between 2020 and 2024. CSF specimens were analysed for gross appearance, cell count and differential, protein concentration, glucose levels, Gram stain, and culture and sensitivity. India ink preparation and latex agglutination for cryptococcal antigen were also performed. Bacterial meningitis was confirmed in 94 patients and viral in 86. CSF from bacterial cases showed significantly higher leucocyte counts with predominant neutrophils, elevated protein above 1.0 g/L, and glucose below 2.2 mmol/L. Viral meningitis cases had lymphocytic pleocytosis, normal or mildly elevated protein, and normal glucose. Streptococcus pneumoniae was the most common bacterial isolate at 38.3%, followed by Neisseria meningitidis at 25.5%. Neonates showed distinct CSF profiles from adults. CSF lactate measurement added diagnostic value in distinguishing bacterial from viral cases. The study underscores the diagnostic importance of comprehensive CSF analysis in meningitis management and recommends capacity building for CSF culture and advanced ancillary testing at all tertiary institutions in Nigeria. Keywords: cerebrospinal fluid, meningitis, bacterial meningitis, CSF analysis, Abuja