Objective: The aim of this study was to obtain data on predisposing factors, causative organisms and their associated mortality and complications related to acute bacterial meningitis.
Methods: The chart review of all patients in whom acute bacterial meningitis was diagnosed at The Aga Khan University Hospital from January 1995 through December 2001.
Results: One hundred ninety-four patients were included in study. There were 146 males and 48 females. The mean age of our study population was 41 +/- 12.3 years. One hundred and ninety (97.9%) patients had community-acquired meningitis; only 4 (2.0%) patients developed meningitis nosocomially. The two most common predisposing factors were diabetes mellitus (13.9%) and otitis media (7.7%) among all 194 patients. A significant proportion of patients with complications had diabetes mellitus (24.6%, p < 0.001). CSF and blood cultures were positive in 53 (27.3%) and 42 (21.6%) patients respectively; there was no statistical difference found. The most common organisms isolated were Streptococcus pneumoniae in 35 (36.8%) patients followed by Neisseria meningitides in 30 (31.5%) patients. Approximately 68% of positive cultures yielded S. pneumoniae and N. meningitides (p < 0.0001). The overall mortality rate was 22.1%. The mortality rate for Streptococcus pneumoniae was 17.1%. The highest mortality was observed in patients with Pseudomonal meningitis where all four patients expired followed by mortality rate of 85.7% in Escherichia coli afflicted patients (p < 0.001). Complications occurred in 73 (37.6%) patients with persistent complications in 31 (42.4%) patients. Complications resolved in 34 (46.5%) patients. The most common complications were seizures (12.8%) and cranial nerve palsies (11.3%). Seizures were more likely to occur in older patients (p < 0.05) whereas hydrocephalus was more common in younger patients (p < 0.05).
Conclusion: Bacterial Meningitis remains a serious disease associated with substantial morbidity and mortality. Most cases are community acquired with S. Pneumoniae being the most common pathogen. Old age, diabetes mellitus, a positive culture, seizures as a complication and late stage in the disease are the important predictors of a poor outcome.