Aetiology

Meningitis may be caused by a variety of infective agents, including bacteria, viruses and fungi. This will focus on bacterial meningitis.

Common bacteria in adults

• Streptococcus pneumoniae
  • most common cause
  • may follow on from an episode of otitis media
• Neisseria meningitidis (causes meningococcal meningitis)
• Listeria monocytogenes
  • more common in immunocompromised patients and the elderly
• Haemophilus influenzae type b
• Myobacterium tuberculosis

Other:

• Cryptococcus neoformans (fungal)
• Viral - most common causes are enteroviruses (Coxsackie B is amongst the most common)

Presentation

Typical Sx:

• fever
• neck stiffness
• vomitting
• headache
• Photophobia
• Altered consciousness and seizures