Clonorchiasis is infection with the liver fluke Clonorchis sinensis. Infection is acquired by eating undercooked freshwater fish. Symptoms include fever, chills, epigastric pain, tender hepatomegaly, diarrhea, and mild jaundice. Humans become infected by eating raw, undercooked, dried, salted, or pickled fish containing encysted metacercariae. Metacercariae are released in the duodenum, enter the common bile duct through the ampulla of Vater, and migrate to smaller intrahepatic ducts, where they mature into adults in about 1 mo. Symptoms of Clonorchiasis include heavier infections can cause fever, chills, epigastric pain, tender hepatomegaly, mild jaundice, and eosinophilia. Chronic cholangitis in heavy infections may progress to atrophy of liver parenchyma, portal fibrosis, and cirrhosis. Jaundice may occur if a mass of flukes obstructs the biliary tree. Other complications include suppurative cholangitis, cholelithiasis, pancreatitis, and, late in the course, cholangiocarcinoma. Diagnosis of Clonorchiasis includes finding eggs in the feces or duodenal contents.
The geographic distribution of liver flukes is largely in Asia and Eastern Europe. Endemic areas of Clonorchis sinensis include china. In southern China millions of people are patients with liver fluke disease, and in some endemic areas, 30-75% of the inhabitants are infected. In China, there are two principal endemic areas, namely southern China and Manchuria. Depending upon the endemic areas, the prevalence rate is variable at between 10% and 85%, and average prevalence rate in southern China is 18%. There are about 8.5 million people infected in the Guangdong and Guangxi areas and another several million people in Manchuria.
For treatment of Clonorchiasis there is only one medicine Praziquantel. It should be administered at the dose of 25 mg/kg 3 times daily for 2–3 consecutive days or of 40 mg/kg, single administration.
Clonorchiasis ongoing research
Some of the ongoing research studies on Clonorchiasis are ClonorESTdb: a comprehensive database for Clonorchis sinensis EST sequences, Cholangiocarcinoma: descriptive epidemiology and risk factors.