a helminthic disease of man, cats, dogs, and certain other mammals caused by the flatworm Clonorchis sinensis, which infests the bile ducts, gallbladder, and pancreatic ducts.

Chlonorchiasis is widespread in China, Japan, Korea, and, in the USSR, the Far East. The source of infection is an individual affected with the parasite; animals are of secondary importance as a source. The eggs of the flukes, excreted with the feces and reaching a body of water, are taken up by mollusks (Bithynia bongicornis and others). The helminth develops within the mollusk until it reaches the cercaria stage. The cercaria emerge and penetrate carp (and, possibly, certain crustaceans), within which they change into metacercaria. Human beings and animals become infected when they eat raw, inadequately cooked, or inadequately salted fish. A fever develops two to four weeks after a person becomes infected, the number of eosinophils in the blood increases, and the liver (and sometimes the spleen) become enlarged. Several weeks later these symptoms subside and the disease becomes chronic with brief, intermittent exacerbations. Clonorchiasis causes functional disturbances (dyskinesia) of the biliary tract, hepatitis, pancreatitis, and, sometimes, cirrhosis of the liver. Diagnosis is based on the detection of the fluke eggs in the feces or duodenal contents. A specific agent, chloxylum, as well as cholagogic and antispasmodic agents, are used in treatment, and the biliary tract should be drained. Chlonorchiasis can be prevented by keeping lakes and streams free of pollution by feces and by cooking fish properly (boiling, thorough frying, hot smoking, pickling for two or three weeks).