244.2 📚 國考版

244.2.0.1 必背 — Species

  • C. neoformans (worldwide; immunocompromise; HIV)
  • C. gattii (tropical + Pacific NW; sometimes immunocompetent severe)

244.2.0.2 必背 — Microbiology

  • Encapsulated yeast (polysaccharide capsule)
  • India ink stain (halo around yeast)
  • Polysaccharide capsule = virulence factor + antigen test target

244.2.0.3 必背 — Risk Factors

  • HIV CD4 < 100 (especially < 50) — primary in HIV epidemic
  • Solid organ transplant
  • HSCT
  • Anti-TNF
  • High-dose steroids
  • Hematologic malignancy
  • Severe liver disease

244.2.0.4 必背 — Clinical Cryptococcal Meningitis

  • Subacute / chronic onset
  • Headache + fever + altered mental status + photophobia + meningismus
  • Increased ICP (papilledema, CN palsies, visual loss)
  • HIV CD4 < 100

244.2.0.5 必背 — Diagnosis

  • Serum Cryptococcal Antigen (CrAg) — 99% sensitivity
  • WHO recommends serum CrAg screening when CD4 < 100
  • CSF analysis: opening pressure > 25, lymphocytic pleocytosis (sometimes low in AIDS), high protein, low glucose, CSF CrAg, India ink (50-75% sens)
  • Culture gold standard

244.2.0.6 必背 — Treatment 3 Phases

Phase Duration Regimen
Induction 2 weeks Liposomal AmB 4 mg/kg/d + Flucytosine 100 mg/kg/d (or single-dose AmB 10 mg/kg per Ambition-cm 2022)
Consolidation 8 weeks Fluconazole 800 mg/d
Maintenance Until immune recovery Fluconazole 200 mg/d

244.2.0.7 必背 — Repeated LP for High ICP

  • Critical mortality reduction
  • Daily / every-other-day for opening pressure > 25
  • Drain 20-30 mL
  • VP shunt for refractory
  • Don’t forget!

244.2.0.8 必背 — When to Start ART (HIV + Cryptococcal Meningitis)

  • Delay 4-6 weeks after cryptococcal Tx initiation
  • COAT trial 2014 — early ART = higher mortality
  • IRIS prevention
  • WHO 2024 endorsement

244.2.0.9 必背 — Pre-Emptive Therapy

  • Serum CrAg screening at HIV diagnosis + CD4 < 100
  • Positive but asymptomatic + LP normal: fluconazole 800 mg × 14 d then 200 mg/d
  • Prevents progression to overt meningitis

244.2.0.10 必背 — C. gattii

  • Tropical + Pacific NW + Vancouver Island
  • More immunocompetent severe + cryptococcomas
  • May need surgery + longer course

244.2.0.11 必背 — Pulmonary Cryptococcosis

  • Asymptomatic immunocompetent: observation
  • Symptomatic immunocompetent: fluconazole 400 × 6-12 mo
  • Severe: full induction-consolidation-maintenance

244.2.0.12 必背 — Mortality Risk

  • 20-50% with treatment
  • Higher with:
    • Late presentation
    • High ICP
    • Severe immunocompromise
    • Cryptococcoma
    • Co-morbidities