Description

CNS infection with inflammation of leptomeninges defined by an increased number of WBCs in the CSF most often associated with fever, nuchal rigidity, headache, and altered mental status

Etiology

• Bacterial:
  • Neonates: Group B Streptococcus, Escherichia coli and other enteric bacilli, Listeria monocytogenes
  • Children/adults: Streptococcus pneumoniae, Neisseria meningitidis, group B Streptococcus, and gram-negative bacilli
  • Elderly/alcoholic: S. pneumoniae, group B Streptococcus, Haemophilus influenzae gram-negative bacilli, Listeria spp.
  • Neurosurgical patients: Staphylococcus and gram-negative organisms
  • Transplant recipients and dialysis patients: Increased incidence of Listeria spp. infection
  • AIDS: Above, plus tuberculosis, fungal, syphilis
• Viral
• Fungal
• Chemical, drug, or toxin induced