Intestinal Echinostoma, Arty

• Intestinal Flukes


  • Fasciolopsis buski
  • Echinostoma ilocanum
  • Artyfechinostomum malayanum
  • Heterophyes heterophyes
  • Metagonimus yokogawai
  • Gastrodiscoides hominis
• Life Cycle of Echinostoma ilocanum


  1. Adult stage in small intestine of human host (definitive host)

  2. Unembryonated ova in stool

  3. Ova in freshwater releases miracidium

  4. Miracidium infects snail (first intermediate host)

  5. Sporocyst in snail produces redia and cercaria

  6. Cercaria infects another snail (second intermediate host)

  
• Echinostoma ilocanum has a lophocercous (long-tailed) cercaria
• Eating raw snails puts a person at risk of Echinostoma ilocanum infection
• Opistorchis


  • Vitellaria in middle 2/3 of body
  • Lobed testes
  • Slender worm

  
• Clonorchis


  • Branched testes
• Echinostoma


  • Slender, similar to Opistorchis
  • Vitellaria extending from anterior to posterior
• Echinostoma adult worm


  • Simple, unbranched intestine
  • Paired, lobulated testes
  • Single, round ovary
  • Vitellaria up to tail end
  • Circumoral disc with 49-51 rows of spines

  
• Artyfechinostomum malayanum shares the life cycle of Echinostoma ilocanum
• Artyfechinostomum malayanum


  • Rounded posterior end
  • Deeply lobed paired testes
• Echinostoma ilocanum


  • Pointed tail end
  • Lobed paired testes
• First intermediate host of Echinostoma ilocanum

  • Gyraulus convexiusculus
  • Hippeutis umbilicalis
• Second intermediate host of Echinostoma ilocanum


  • Pila luzonica
  • Vivipara angularis
• First intermediate host of Artyfechinostomum malayanum


  • Indoplanorbis exustus
  • Gyraulus convexiusculus
• Second intermediate host of Artyfechinostomum malayanum


  • Pila scutata
  • Lymnaea cumingiana
• Echinostoma egg


  • Yellowish to brown, ovoid, operculated, unembryonated upon discharge
• Echinostoma egg cannot be differentiated from Fasciola and Fasciolopsis eggs
• Echinostoma egg cannot be differentiated from Artyfechinostomum malayanum egg
• Echinostomiasis


  • Majority of infections are asymptomatic
  • Symptomatic infections have abdominal pain and diarrhea
  • Heavy infections can cause inflammatory lesions, ulcers, and anemia
• Prevention


  Avoidance of eating raw snails