Clonorchis sinensis is an endemic trematode parasite that causes human clonorchiasis. It is estimated that approximately 35 million people are infected with this fluke in East Asia, including Korea, China and Vietnam . Individuals generally become infected with C. sinensis by the consumption of raw or undercooked freshwater fish containing metacercariae . The C. sinensis adult worms inhabit the bile ducts and cause a series of pathological changes, such as epithelial hyperplasia, periductal fibrosis, obstructive jaundice, dyspepsia and liver cirrhosis, in the infected hosts . Chronic clonorchiasis has been classified as a definite biological carcinogen that causes cholangiocarcinoma in humans by the World Health Organization .