ICD-11

A condition caused by an infection with the parasitic worm Clonorchis sinensis. This condition commonly presents with inflammation and obstruction of the biliary ducts. This condition may also present with abdominal pain, nausea, or diarrhoea. Transmission is commonly by ingestion of undercooked fish infected with parasitic cysts. Confirmation is by identification of Clonorchis sinensis eggs in a faecal sample.

Clonorchis sinensis is a human liver fluke transmitted to humans through the ingestion of ingestion of raw, undercooked, salted, pickled, or smoked freshwater fish that carry the metacercariae. The larvae mature in the intrahepatic bile duct and live medium sized biliary ducts for over 26 years although they can be found in the gallbladder and pancreatic ducts. The majority of infections are asymptomatic due to the low fluke counts. Heavy infections result in nonspecific symptoms including right upper quadrant abdominal pain, indigestion, diarrhea, fever, loss of appetite, fatigue and flatulence. Complications of C. Sinensis infection include cholangiocarcinoma, pyogenic cholangitis, cholangiohepatitis and gall stones. Chronic irritation of epithelial cells can result in adenenomatous hyperplasia of the biliary epithelium, mucin secreting metaplasia, ductal dilatation, and dysplasia or neoplasia of biliary cells. Periductal inflammation and fibrosis of hepatic cells can arise from eosinophilic and lymphocytic infiltration, although they are generally present after the third decade of life.