GI Radiology > Biliary > Bile Ducts > Infectious > Ascariasis

Infectious Diseases of Bile Ducts


  1. Pathogenesis:
  • Largest intestinal roundworm that is parasitic in humans.
  • Found in tropical and semitropical countries, thriving in areas with poor sanitation. As recent as fifty years ago, it was common in Virginia.
  • Most common small bowel parasite.
  • Larvae mature into adult worms in the alimentary tract.
  • Possible complications: intestinal obstruction, peritonitis, appendicitis, and hemoptysis.
  • May migrate into the common bile duct and cause signs and symptoms of biliary obstruction.

  1. Radiographic findings:
  • Single worm may produce intraluminal filling defect within opacified bile duct.
  • Long worms in intestine may appear as elongated radiolucent filling defects.
  • Figures: Ascariasis in bile duct of twenty-eight y.o. Vietnamese male with elevated Liver Function Test (LFT). Contrast agent injected into bile ducts during ERCP outlines single linear defect in extrahepatic duct.


  • Figure: Endoscopic views of worm backing out of bile duct into duodenum.



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