Acute bacterial meningitis in adults: Predictors of outcome

Case fatality ratio and permanent sequelae of acute bacterial meningitis remain high in recent decades. A prospective longitudinal study of adult patients admitted with community acquired acute bacterial meningitis at a tertiary infectious diseases unit aimed to identify predictors of unfavourable outcome - death and sequelae. Anamnestic, clinical and laboratory data and clinical outcome were recorded. From 1997 to 2006, 279 adults (122F, 157M) with a median age of 51 y were admitted with acute bacterial meningitis. Predisposing condition and comorbidity were recorded in 42% and 38% of patients, respectively. Time between symptoms onset and antibiotic treatment ranged from 6 to 160 h. An aetiological agent was identified in 77% of patients: Streptococcus pneumoniae (29%) and Neisseria meningitidis (27%) were the most frequent. 55 patients (20%) died and 63 (23%) had neurological sequelae 6 months after discharge. In multivariate analysis, 7 independent predictors of unfavourable outcome were identified: internal comorbidity, time to treatment >48 h, coma, hypotension, high CSF protein, low glucose ratio, and non-meningococcal aetiology. The results suggest that acute bacterial meningitis remains associated with significant morbidity and mortality. Maintaining a high clinical suspicion and initiating appropriate diagnostic testing and therapeutic interventions promptly are essential for an optimal clinical outcome.