title: Listeria monocytogenes sequence type 6 and increased rate of unfavorable outcome in meningitis: epidemiologic cohort study.
abstract: BACKGROUND
  We analyzed clinical characteristics, treatment, genetic diversity, and outcome of 92 adults with Listeria monocytogenes meningitis included in 2 prospective nationwide cohort studies.
  
  
  METHODS
  Episodes of community-acquired listerial meningitis confirmed by cerebrospinal fluid culture were included from 1998 to 2002 and 2006 to 2012. We compared patients and pathogen characteristics between cohorts and identified predictors for an unfavorable outcome according to the Glasgow Outcome Scale.
  
  
  RESULTS
  Thirty episodes were included from 1998 to 2002 and 62 from 2006 to 2012; clinical and laboratory characteristics on admission were similar between cohorts. However, the rate of unfavorable outcome increased from 27% in the 1998-2002 cohort to 61% in the 2006-2012 cohort (P = .002). Differences between cohorts were increased use of adjunctive dexamethasone therapy (0% in 1998-2002 vs 53% in 2006-2012; P < .001) and emergence of infection by L. monocytogenes genotype sequence type 6 (ST6; 4% in 1998-2002 vs 29% in 2006-2012; P = .009). Multivariate regression analysis identified infection with L. monocytogenes ST6 as the sole predictor of unfavorable outcome (odds ratio, 3.77; 95% confidence interval, 1.07-13.33). Patients infected with genotypes other than ST6 also had an increased rate of unfavorable outcome over time (P = .03).
  
  
  CONCLUSIONS
  The rate of unfavorable outcome among adults with listerial meningitis has increased over a 14-year period, from 27% to 61%. The emerging L. monocytogenes genotype ST6 was identified as the main factor leading to poorer prognosis. Adjunctive dexamethasone may be discontinued if L. monocytogenes is identified, as there is no proven benefit in Listeria meningitis.
authors.affiliation: Department of Neurology, Center of Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100 DD Amsterdam, the Netherlands.
authors.forename: Merel M
authors.initials: MM
authors.lastname: Koopmans
authors.forename: Matthijs C
authors.initials: MC
authors.lastname: Brouwer
authors.forename: Merijn W
authors.initials: MW
authors.lastname: Bijlsma
authors.forename: Sandra
authors.initials: S
authors.lastname: Bovenkerk
authors.forename: Wendy
authors.initials: W
authors.lastname: Keijzers
authors.forename: Arie
authors.initials: A
authors.lastname: van der Ende
authors.forename: Diederik
authors.initials: D
authors.lastname: van de Beek
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003907:Dexamethasone / Q000627:therapeutic use; D005260:Female; D005838:Genotype; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D015994:Incidence; D008089:Listeria monocytogenes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D008297:Male; D008584:Meningitis, Listeria / Q000453:epidemiology / Q000382:microbiology* / Q000473:pathology*; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D007155:Immunologic Factors; D003907:Dexamethasone
keywords: Listeria monocytogenes; dexamethasone; meningitis; prognosis; sequence type 6