Community-acquired bacterial meningitis in older people.

Objectives: To describe clinical features of bacterial meningitis in older people.
Design: Cohort study.
Setting: Hospitals in the Netherlands.
Participants: Patients aged over 16 with community-acquired bacterial meningitis, confirmed using cerebrospinal fluid culture.
Measurements: Data were collected prospectively. The cohort was dichotomized with respect to age (>or=60 vs 17-59).
Results: Two hundred fifty-seven of 696 episodes of community-acquired bacterial meningitis (37%) occurred in elderly patients and 439 (63%) in younger adults. Older people more often presented with the triad of fever, neck stiffness, and altered mental status than younger adults (58% vs 36%; P<.001). In older people, meningitis was due to Streptococcus pneumoniae in 176 episodes (68%). In younger adults, Neisseria meningitidis was the most common pathogen, responsible for 221 episodes (50%). Elderly patients more often developed complications than younger adults (72% vs 57%; P<.001), which resulted in a higher mortality rate (34% vs 13%; P<.001). Older people tended to die more often from cardiorespiratory failure (25% vs 11%; P=.06), whereas younger adults more often died from brain herniation (23% vs 2%; P=.004).
Conclusion: Elderly patients with bacterial meningitis often present with classic symptoms of bacterial meningitis. Bacterial meningitis within this age group is predominantly due to S. pneumoniae and is associated with high morbidity and mortality rates. Whereas older people die frequently of cardiorespiratory failure, younger adults more often die of brain herniation.