The clinical characteristics of spontaneous Gram-negative bacterial meningitis in adults: A hospital-based study

The epidemiologic trend of acute bacterial meningitis can change more dramatically than any other bacterial disease, and a decrease in spontaneous adult bacterial meningitis (ABM) has been noted in serial studies of the epidemiologic trend of ABM in Taiwan. The purpose of this study was to analyze the clinical characteristics, laboratory data and therapeutic outcomes of 149 patients with spontaneous Gram-negative (G(-)) ABM collected during a study period of 31 years (1986-2016). The 149 patients included 107 men and 42 women, aged 18-86 years. The common underlying conditions were diabetes mellitus, liver cirrhosis and alcoholism, and the leading clinical presentations were fever, altered consciousness and septic shock. Compared the clinical characteristics of the patients identified in the study period of 2001-2106 to the patients identified in the study period of 1986-2000, the former group of patients had a significantly higher incidence of systemic malignance. In the recent 16 years (2001-2016), Klebsiella pneumoniae, Pseudomonas spp. and Escherichia coli were the leading three implicated bacterial pathogens of spontaneous G(-) ABM, accounting for 61.3% (38/62), 11.3% (7/62) and 11.3% (7/62%) of all cases, respectively. The overall mortality rate from spontaneous G(-) ABM was high (47.0%, 70/149) and the presence of septic shock and lower cerebrospinal fluid glucose level were significant prognostic factors. Because of the decreasing incidence of spontaneous ABM in Taiwan, close examination of this specific infectious syndrome is important in order to monitor the epidemiologic trend and improve the therapeutic strategy.