Open Access Research article

The spectrum of acute bacterial meningitis in elderly patients

Pere Domingo1*, Virginia Pomar1, Natividad de Benito1 and Pere Coll2

Author Affiliations

1 Infectious Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Av. Sant Antoni Mª Claret, 167, Barcelona 08025, Spain

2 Department of Microbiology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain

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BMC Infectious Diseases 2013, 13:108  doi:10.1186/1471-2334-13-108

Published: 27 February 2013



We conducted a prospective, observational study in Barcelona to determine the epidemiology, clinical features, and outcome of elderly patients with acute bacterial meningitis (ABM) compared with younger adults.


During 1982–2010, all patients with ABM were prospectively evaluated. There were two groups: I (15–64 years) and II (≥ 65 years). All patients underwent clinical examination on admission and at discharge following a predefined protocol.


We evaluated 635 episodes of ABM. The incidence was 4.03/100,000 (Group I) and 7.40 /100,000 inhabitants/year (Group II) (RR = 1.84; 95%CI: 1.56–2.17, P < 0.0001). Elderly patients had co-morbid conditions more frequently (P < 0.0001) and more frequently lacked fever (P = 0.0625), neck stiffness (P < 0.0001) and skin rash (P < 0.0001), but had an altered level of consciousness more often (P < 0.0001). The interval admission-start of antibiotic therapy was longer for elderly patients (P < 0.0001). Meningococcal meningitis was less frequent in elderly patients (P < 0.0001), whereas listerial (P = 0.0196), gram-negative bacillary (P = 0.0065), and meningitis of unknown origin (P = 0.0076) were more frequent. Elderly patients had a higher number of neurologic (P = 0.0009) and extra-neurologic complications (P < 0.0001). The overall mortality ratio was higher in elderly patients (P < 0.0001).


Elderly people are at higher risk of having ABM than younger adults. ABM in the elderly presents with co-morbid conditions, is clinically subtler, has a longer interval admission-antibiotic therapy, and has non-meningococcal etiology. It is associated with an earlier and higher mortality rate than in younger patients.

Bacterial meningitis; Acute; Elderly; Streptococcus pneumoniae; Listeria monocytogenes; Co-morbidities; Outcome; Complications; Post-meningitic sequelae