Clinical features, complications, and outcome in adults with pneumococcal meningitis: a prospective case series.

BACKGROUND: Bacterial meningitis is a grave disease of high incidence, especially in less developed countries. Here, we describe its clinical presentation, spectrum of complications, prognostic factors, and outcome in adults with pneumococcal meningitis.
METHODS: From October, 1998, to April, 2002, we assessed 352 episodes of community-acquired pneumococcal meningitis, confirmed by culture of cerebrospinal fluid (CSF), which occurred in patients older than 16 years. Predictors for an unfavourable outcome (Glasgow outcome scale score 1-4) were identified by logistic regression with multiple imputation techniques.
FINDINGS: 245 (70%) episodes of pneumococcal meningitis were associated with an underlying disorder. Cranial CT was done for 85% of episodes and revealed underlying disorders in 17% (50/299) and meningitis-associated intracranial complications in 39% (117/299). Independent predictors for an unfavourable outcome were a low score on the Glasgow coma scale, cranial nerve palsies, a raised erythrocyte sedimentation rate, a CSF leucocyte count less than 1000 cells per mm(3), and a high CSF protein concentration on admission. Overall in-hospital mortality was 30%. Prevalence of neurological and systemic complications did not differ between patients aged younger than 60 years and those aged 60 years and older; however, systemic complications were the cause of death in 59% (32/54) of fatal episodes in patients aged 60 years and older, whereas neurological complications were the cause of death in 65% (20/31) of fatal episodes in younger patients.
INTERPRETATION: Pneumococcal meningitis is associated with high mortality and morbidity rates in adults. Whereas neurological complications are the leading cause of death in younger patients, elderly patients die predominantly from systemic complications.