Changing Epidemiology of Adult Bacterial Meningitis in Southern Taiwan: A Hospital-Based Study

Abstract Background: Many factors may influence the epidemiologic trend of adult bacterial meningitis (ABM). The objective of this study was to analyze recent epidemiologic trends of ABM in order to provide a better therapeutic strategy. Materials and Methods: The clinical features, laboratory data, and therapeutic outcomes of 181 ABM cases collected in the last 6.5 years (July 1999–December 2005) were analyzed. The results were compared with those of our previous study (202 cases, January 1986–June 1999). Results: The 181 cases consisted of 130 men (age range: 18–82 years) and 51 women (age range: 18–78 years). Monomicrobial infection and mixed infection were found in 165 cases and 16 cases, respectively. A preceding postneurosurgical state was noted in 56.9% (103/181) of cases. Despite a decrease in incidence, Klebsiella pneumoniae (25.5%, 42/165) was still the most common pathogen. A marked increase of Acinetobacter meningitis (11.5%, 19/165) was noted, which replaced Pseudomonas meningitis as the second most common Gram-negative pathogen in ABM. A marked increase in staphylococcal infection, accounting for 23% (38/165) of all cases, was also noted, of which 76% (29/38) were methicillin-resistant strains. The therapeutic result showed a mortality rate of 30.3% (55/181). Significant prognostic factors included septic shock and age at infection. Conclusions: This study revealed a change in the epidemiologic trend of ABM, with an increase in the number of patients with a postneurosurgical state and a rising incidence of Acinetobacter and staphylococcal infections. Clinicians should pay greater attention to these changes, which may affect their management of ABM.