235.2 📚 國考版

235.2.0.1 必背 — 3 Major Free-Living Amebae

Pathogen Disease Host Course Mortality
Naegleria fowleri PAM Immunocompetent Rapid (1-2 wk) > 97%
Acanthamoeba GAE + Keratitis + Cutaneous + Disseminated Immunocompromise (GAE); CL wearers (keratitis) Subacute / chronic 90%+ GAE
Balamuthia mandrillaris GAE + Cutaneous Immunocompetent + immunocompromise Subacute / chronic 89%+

235.2.0.2 必背 — Naegleria PAM

  • Warm freshwater swimming + diving (lakes, hot springs, pools, neti pot)
  • Nasal entry → cribriform plate → olfactory bulbs → CNS
  • Sudden onset severe headache + fever + olfactory disturbance + stiff neck
  • Mortality > 97%; < 10 documented survivors globally
  • Treatment: combination (amphotericin B IV/IT + miltefosine + azithromycin + fluconazole + rifampin + dex + hypothermia)
  • CDC 24/7 hotline for treatment guidance

235.2.0.3 必背 — Acanthamoeba Keratitis

  • Contact lens wearers (tap water rinse, extended wear, swimming with lens)
  • Severe pain disproportionate to findings
  • Ring corneal infiltrate, pseudo-dendritic
  • Often misdiagnosed as HSV initially
  • Treatment: topical chlorhexidine/PHMB + propamidine + neomycin (long course); corneal transplant if severe

235.2.0.4 必背 — Acanthamoeba GAE

  • Immunocompromise (HIV, transplant)
  • Subacute / chronic
  • Brain biopsy diagnostic
  • Combination therapy + miltefosine + immune restoration

235.2.0.5 必背 — Balamuthia mandrillaris

  • Immunocompetent + immunocompromise
  • Subacute / chronic
  • Cutaneous often precedes CNS (months-years)
  • Multi-drug therapy + miltefosine

235.2.0.6 必背 — Miltefosine

  • Key drug for free-living amebae
  • FDA accelerated 2013
  • CDC compassionate use
  • Pregnancy contraindicated

235.2.0.7 必背 — Prevention

  • Naegleria: avoid warm freshwater diving + neti pot with tap water + nose clip
  • Acanthamoeba keratitis: contact lens hygiene + no tap water rinse + no swimming with lens
  • Balamuthia: limit soil + water exposure (limited prevention)

235.2.0.8 必背 — CSF in PAM

  • Lymphocytic + PMN
  • Low glucose
  • High protein
  • RBCs (hemorrhagic)
  • Don’t refrigerate before examination (kills trophozoites)

235.2.0.9 必背 — Diagnosis PAM

  • CSF wet mount + Giemsa + motile trophozoites
  • PCR (CDC reference)
  • MRI (basal cistern enhancement)