Meningitis: bacterial: was caused by Streptococcus pneumoniae and Neisseria meningitidis

Clinical bottom line (level 2c)

  1. The commonest causes of bacterial meningitis were Streptococcus pneumonia and Neisseria meningitidis.
Schuchat et al: New England Journal of Medicine 1997; 337 (14): 970-976
Expires November 2003

The study

Outcome study with objective outcomes, not adjusted for confounding factors, ? validated in an independent set of patients.

Setting: 22 counties in 4 states, USA

248 patients (aged median 25, ?% male) with bacterial meningitis



Outcomes studied:
  • Haemophilus influenzae meningitis
  • Streptococcus pneumoniae meningitis
  • Neisseria meningitidis meningitis
  • Group B streptococcus meningitis
  • Listeria monocytogenes meningitis

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    Haemophilus influenzae meningitis ? 18/248 7.3%
    (4.0% to 11%)
    Streptococcus pneumoniae meningitis ? 117/248 47%
    (41% to 53%)
    Neisseria meningitidis meningitis ? 62/248 25%
    (20% to 30%)
    Group B streptococcus meningitis ? 31/248 13%
    (8.4% to 17%)
    Listeria monocytogenes meningitis ? 20/248 8.1%
    (4.7% to 12%)

    Comments

    1. In neonates the commonest organism was Group B Streptococcus. In infants Streptococcus pneumonia and N. meningitidis caused three-quarters of cases. N. meningitidis caused 59% of cases in children aged 2 to 18. Streptococcus pneumonia caused 62% of cases in patients aged 19 or older.
    2. prevalence of meningitis: 248/10 281 746: 0.0024%
    3. The median age of meningitis in 1986 was 15 months - the change reflects the introduction of routine Hib vaccination in the USA.
    4. Blacks were over represented in this study as compared to the US population (24% in the study compared to 12% in the population). This might have an impact on the proportion of cases with Group B streptococcus

    Citation

    1. Schuchat A, Robinson K, Wenger JD, et al: bacterial meningitis in the United States in 1995. New England Journal of Medicine 1997; 337 (14): 970-976
    Contributor: Chris Ball and Clare Wotton, November 1999
    Reviewer: Padmanabhan Badrinath

    Clinical Question.
    Patient bacterial meningitis
    Intervention or Exposure
    Outcome infecting organism