Meningitis

Question 1

Chemoprophylaxis for meningitis

Answer 1

close contacts and direct exposure to respiratory secretions
* Contact public health for post-exposure prophylaxis for close contacts (7d prior to symptom onset until 24h treatment)
* N meningititidis (>8h close contact or oral secretions)
* Ciprofloxacin 500mg PO x1, Rifampin 600mg PO q12h x2d, Ceftriaxone 250mg IM x1
* H influenzae (household with unvaccinated)
* Rifampin

Question 2

CSF Findings

Answer 2

Bacterial:
- high WBC
- High Protein
- Low Glucose

Viral:
- med WBCs
- Med protein
- high Glucose

Question 3

lab work up

Answer 3

• CBC
• Electrolytes (Mild hyponatremia)
• LFTs
• Coags
• VBG (AGMA)
• Blood cultures x2 (60% positive) before first dose of antibiotics if possible
• Consider
  
  • If sexual history or substance use: serum RPR, CSF VDRL, serum HIV Ab and HIV PCR
  • In children (to guide diagnosis): Serum CRP and pro-calcitonin
  • Throat swab for meningococcal culture

Question 4

Treatment

Answer 4

• Empiric Antibiotics (do not delay beyond 1h if possible)
  
  • 0-1mo: Ampicillin + Cefotaxime (or Ampicillin + aminoglycoside)
  • > 1mo: Vancomycin + 3rd gen cephalosporin (Ceftriaxone 2g IV q12h or Cefotaxime 2g IV q4-6h)
    • Vancomycin 15-20mg/kg IV q8-12h (pre 4th dose trough levels 15-20mcg/mL) + Ceftriaxone 2g IV q12h
  • > 50y: Add Ampicillin 2g IV q4h to cover Listeria monocytogenes
• Dexamethasone 10mg q6h x 4 days if suspect S. pneumoniae (reduce mortality), or H influenzae (reduce hearing loss)
  
  • Best to administer prior or with initial antibiotic therapy
  • Stop steroids if not Hit or S. Pneumonia
  • Consider Rifampin instead of vancomycin if bacteria not sensitive to ceftriaxone, as vancomycin may not enter CSF as well after steroids decreased inflammation
• Consider Acyclovir if suspect HSV encephalitis (changes in personality, behaviour, cognition, AMS)
• Consider covering for P. aeruginosa in immunocompromised with Cefepime or Meropenem 2g IV q8h
• Consider covering for tuberculous and cryptococcal meningitis in immunocompromised

Question 5

Risk factors

Answer 5

• Age ≥65 years old, Neonates, Aboriginal groups, Students living in residence
  
  • Immunocompromised (16%), Alcoholism, IVDU
  • Infection
    
    • Recent otitis or sinusitis (25%), mastoiditis
    • Pneumonia (12%)
    • Endocarditis
  • Recent neurosurgery, Head trauma
  • Recent travel to area with endemic meningococcal disease (eg. sub-Saharan Africa)

Question 6

Symptoms

Answer 6

• Headache, fever, neck stiffness, and altered mental status (two of the following 95% sensitive)
  * 99% have at least one classic feature - thus absence of all four findings above essentially excludes bacterial meningitis
  
  • Nausea, vomiting
  • Photophobia
  • Seizure and focal neurologic deficits (especially in Listeria)
    
    • Rhombencephalitis (manifested as ataxia, cranial nerve palsies, and/or nystagmus)
  • Petechiae and palpable purpura (especially in N meningitidis)
  • Arthritis (especially in N meningitidis)