Vol. 9, Issue 1, Part A (2026)

Background: CSF analysis is a critical diagnostic tool in evaluating neurological infections, particularly meningitis. Early identification of biochemical and cytological alterations in CSF significantly improves clinical outcomes. This study aimed to analyse CSF characteristics across age groups and categorize meningitis cases using WHO criteria in tertiary care setting.

Methods: A retrospective observational study was conducted on 500 CSF samples collected from patients of all ages between November 2024 and November 2025. CSF specimens underwent gross, biochemical (protein and glucose), and microscopic (cell counts and differential) examination. Findings were used to classify cases as bacterial meningitis, probable bacterial meningitis, aseptic meningitis, or no meningitis according to WHO recommendations.

Results: Infants(<1year) constituted the largest proportion of cases (40.3%), with an overall male predominance (59.5%). The most frequent clinical presentations were fever (21%), seizures (18.6%), and poor feeding (16.2%). CSF analysis showed elevated protein (>90 mg/dL) in 32.8% and reduced glucose (≤40 mg/dL) in 45.8% of samples. Polymorph dominance correlated strongly with bacterial meningitis, whereas lymphocyte predominance was characteristic of aseptic meningitis. WHO categorization revealed 24.6% bacterial meningitis, 33.4% probable bacterial meningitis, 14.5% aseptic meningitis, and 29.7% non-meningitis cases. Infants showed the highest burden of bacterial and probable bacterial meningitis.

Conclusion: CSF evaluation demonstrates high diagnostic utility in distinguishing meningitis subtypes, particularly among infants. Elevated protein, low glucose, and polymorph predominance remain strong indicators of bacterial etiology. The study underscores the essential role of comprehensive CSF analysis and WHO-based classification in early diagnosis and management of neurological infections.