Spontaneous gram-negative bacillary meningitis in adult patients: characteristics and outcome.
BACKGROUND
Spontaneous meningitis caused by gram-negative bacilli in adult patients is uncommon and poorly characterized. Our objective is to describe and compare the characteristics and the outcome of adult patients with spontaneous gram-negative bacilli meningitis (GNBM) and spontaneous meningitis due to other pathogens.


METHODS
Prospective single hospital-based observational cohort study conducted between 1982 and 2006 in a university tertiary hospital in Barcelona (Spain). The Main Outcome Measure: In-hospital mortality.


RESULTS
Gram-negative bacilli meningitis was diagnosed in 40 (7%) of 544 episodes of spontaneous acute bacterial meningitis. The most common pathogens were Escherichia coli and Pseudomonas species. On admission, characteristics associated with spontaneous gram-negative bacilli meningitis by multivariate modeling were advanced age, history of cancer, nosocomial acquisition of infection, urinary tract infection as distant focus of infection, absence of rash, hypotension, and a high cerebrospinal fluid white-cell count. Nine (23%) episodes were acquired in the hospital and they were most commonly caused by Pseudomonas. The in-hospital mortality rate was 53%. The mortality rate was higher among patients with Gram-negative bacillary meningitis than among those with other bacterial meningitis and their risk of death was twenty times higher than among patients infected with Neisseria meningitidis (odds ratio 20.47; 95% confidence interval 4.03-103.93; p<0.001).


CONCLUSIONS
Gram-negative bacilli cause 9% of spontaneous bacterial meningitis of known etiology in adults. Characteristics associated with GNBM include advanced age, history of cancer, nosocomial acquisition, and urinary tract infection as distant focus of infection. The mortality rate is higher among patients with gram-negative bacillary meningitis than among those with other bacterial meningitides.
Department of Internal Medicine, Infectious Diseases Unit, Hospital de la Santa Creu i Sant Pau, Institut d'Investigació Biomèdica Sant Pau, Universitat Autònoma de Barcelona, Spanish Network for Research in Infectious Diseases (REIPI), C/ Mas Casanovas 90, Barcelona 08025, Catalonia, Spain. vpomar@santpau.cat.
Virginia
V
Pomar
Natividad
N
Benito
Joaquin
J
López-Contreras
Pere
P
Coll
Mercedes
M
Gurguí
Pere
P
Domingo
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015331:Cohort Studies; D003428:Cross Infection / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006090:Gram-Negative Bacteria / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D016920:Meningitis, Bacterial / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies; D013030:Spain; D055815:Young Adult
D000900:Anti-Bacterial Agents