Clonorchiasis

Definition

A rare parasitic disease characterized by infection with the trematode Clonorchis sinensis (Chinese or oriental liver fluke) through ingestion of metacercarial cysts via infected raw or undercooked fish. Clinical symptoms are related to worm burden. Most acute infections are asymptomatic or present with mild abdominal symptoms. Patients with high worm burdens experience fever, headache, right upper-quadrant abdominal pain, and intermittent colic pain caused by the worms obstructing the gallbladder. Chronic infections are usually severe, resulting in fibrosis of small bile ducts and destruction of the adjacent liver parenchyma, and strongly associated with cholangiocarcinoma.