233.2 📚 國考版

233.2.0.1 必背 — Major Intestinal Protozoa

Pathogen Clinical Treatment
Giardia Watery → foul-smelling steatorrhea Tinidazole single dose or metronidazole or nitazoxanide
Cryptosporidium Watery diarrhea; severe in HIV CD4 < 100 (chronic) Nitazoxanide; ART critical in HIV
Cyclospora Foodborne (raspberries, basil); prolonged watery + fatigue TMP-SMX × 7-10 d
Microsporidia HIV chronic; disseminated possible Albendazole (Encephalitozoon); fumagillin (E. bieneusi)
Cystoisospora HIV chronic TMP-SMX × 7-10 d + secondary prophylaxis in HIV
Entamoeba histolytica Ch 234 separate

233.2.0.2 必背 — Giardia Specific Features

  • Foul-smelling, greasy stool + steatorrhea + lactose intolerance + post-infectious
  • Cyst chlorine-resistant → UV / filtration
  • Daycare, water, hiking, MSM
  • Stool antigen preferred test

233.2.0.3 必背 — Cryptosporidium Features

  • Acid-fast intracellular
  • Chlorine-resistant
  • Cattle reservoir (zoonotic)
  • Milwaukee 1993 outbreak (400K+ cases)
  • HIV CD4 < 100: chronic severe diarrhea + cholangiopathy + pancreatitis
  • ART critical

233.2.0.4 必背 — Cyclospora Features

  • Foodborne raspberries / basil / cilantro / leafy greens
  • USA seasonal summer outbreaks
  • Modified acid-fast + UV autofluorescence
  • TMP-SMX treatment

233.2.0.5 必背 — Microsporidia

  • Reclassified as fungi
  • HIV chronic diarrhea + disseminated
  • Modified trichrome stain for diagnosis
  • Albendazole (most species except E. bieneusi → fumagillin)

233.2.0.6 必背 — Cystoisospora belli

  • Coccidian, HIV chronic diarrhea
  • Large ellipsoid oocysts visible on stool O+P
  • TMP-SMX

233.2.0.7 必背 — Stool Tests

  • Stool antigen for Giardia + Cryptosporidium (high sensitivity)
  • Modified acid-fast for Cryptosporidium + Cyclospora + Cystoisospora
  • Modified trichrome for Microsporidia
  • PCR multiplex GI panel for all (BioFire FilmArray)

233.2.0.8 必背 — HIV CD4 < 100 + Chronic Diarrhea Differential

  • Cryptosporidium (#1)
  • Microsporidia
  • Cystoisospora
  • Cyclospora
  • CMV colitis
  • MAC, TB
  • ICs / drug side effects
  • Workup: stool studies + colonoscopy + biopsy