The changing pattern of bacterial meningitis in adult patients at a large tertiary university hospital in Barcelona, Spain (1982-2010)

Background: We conducted a prospective, observational study in Barcelona (Spain) to determine changes in the spectrum of adult patients with bacterial meningitis (BM) over a 29-year period. Methods: The observation was divided into two periods: 1982-1995 (I) and 1996-2010 (II). All patients underwent clinical examination on admission and at discharge following a predefined protocol. Results: We evaluated 635 episodes of BM. The most frequent etiologic agents were Neisseria meningitidis and Streptococcus pneumoniae in periods I and II, respectively. Patients in period II were older (Median: 47.5 [95%CI: 23.0-64.5] vs. 58.0 [39.0-73.0] years, P < 0.0001), had a longer interval from admission to therapy (Median: 2.3 [95%CI: 1.0-5.0] vs. 4.0 [2.0-12.0] hours, P < 0.0001), and more frequently had co-morbid conditions (39.1% vs. 62%, P < 0.0001). Meningococcal meningitis decreased by 66% (P < 0.0001), whereas meningitis by Listeria monocytogenes increased by 110% (P = 0.0007) in period II. There were no differences in the overall case-fatality and post-meningitic sequelae rates between both periods. Conclusions: BM in adult patients has substantially changed over 29 years in terms of population affected, aetiology, and management, but not in terms of its overall mortality rate and appearance of post-meningitic sequelae. © 2012 The British Infection Association.