Bacterial Meningitis

Diseases, , , ,

Diagnosis:

Clinical features plus confirmation by CSF analysis
Findings in Bacterial meningitis:

  • High opening pressure >180 mmH2O, turbid/purulent appearance
  • White cell count: high, 10-10,000/microL
    • Mainly neutrophils (usually >100), but monocytes are suggestive of Listeria monocytogenes
  • Protein: High, >0.45 g/L (>45 mg/dL)
  • Glucose: low, <0.4 of serum (roughly <1/2 serum), or <2.2 mmol/L (<40 mg/dL)
  • Borrelia burgdorferi, Lyme disease:
    • White cell count <100/mm3, <30% neurtrophils
    • Protein: normal or high
    • Glucose: normal
  • CSF PCR for Neisseria meningitides, Haemophilis influenzae, Listeria monocytogenes, Borrelia burgdorferi
  • Meningococcal septicemia: blood cultures, skin scrapings of the rash, +/-PCR

Pathology:

Gross:

  • Creamy yellow pus surrounding the brain

Microscopic:

  • Neutrophils in the subarachnoid space & in Virchow-Robin spaces surrounding vessels. Leptomeningeal vessels may be involved.
  • Gram stain: organisms

Monitor:

  • In children with meningitis consider get follow up hearing tests

Treament:

This is an emergency, start abx. before confirming the diagnosis by lumbar puncture
Antibiotics considerations:

  • See updated list according to current bacterial sensitivities in your community
  • Penicillin intravenous +3rd generation cephalosporin (Cefotaxime or ceftriaxone) I.V. X10 days
  • Or Vancomycin +3rd generation cephalosporin I.V.
  • Or if Listeria is suspected Ampicillin I.V. +Vancomycin +3rd generation cephalosporin I.V.
  • If neonatal:
    • Ampicillin I.V. +(Cefotaxime or ceftriaxone) X14-21 days
    • Or Ampicillin I.V. +gentamicin I.V.
  • If pregnant: consider Cefotaxime +ampicillin
  • If pneumococcus is suspected or confirmed. +Dexamethazone 0.15 mg/kg q6h X4 days starting before or with first dose of abx.
  • If Borrelia X14-28 days
  • Consider protein C administration [Debatable]
  • If mastoiditis, mastoidectomy

Prophylaxis of contacts:

  • If N. meningitides:
    • Give ciprofloxacin or rifampin to eradicate pharyngeal carriage.
    • In outbreaks use ciprofloxacin.

Related articles:

References:

  1. Tunkel AR, Hartman BJ, Kaplan SL, et al. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis. 2004 Nov 1;39(9):1267-84. Epub 2004 Oct 6.