Ten years of clinical experience with adult meningitis at an urban academic medical center

The purpose of this study is to describe the clinical presentation and bacteriology of adult patients admitted to an urban academic medical center with bacterial meningitis over a 10-year period. In this retrospective review, we identified all adult patients discharged from a tertiary care facility between November 1992 and March 2003 with a diagnosis of bacterial meningitis. Data regarding demographics, vital signs, presenting symptoms, seven predisposing factors, body fluid cultures, cerebrospinal fluid (CSF) findings, and mortality were abstracted. Data were analyzed using descriptive methods. We identified 38 cases. Overall mortality rate was 18.4% (95% confidence interval 7.7–34.3%). The most common of the seven predisposing factors was an immunocompromised state (31.6%). Streptococcus pneumoniae (24.3%), other streptococcus species (24.3%), and Gram-negative rods (16.2%) were the most commonly identified organisms. The classic meningitis triad (fever, neck stiffness, mental status change or headache) was present in only 21.1% of cases. CSF analysis demonstrated WBC ≥ 100/mm3 in 81.3%, decreased glucose (< 50 mg/dL) in 50%, and elevated protein (> 45 mg/dL) in 91.2%. With increasing numbers of immunocompromised patients, atypical presentations of bacterial meningitis seem to be more common. A higher percentage of bacterial meningitis cases seem to be caused by Gram-negative rods and Streptococcus species other than Streptococcus pneumomiae. The classic meningitis triad occurred in fewer cases than previously described.