Clonorchiasis is an infectious disease caused by the Chinese liver fluke, Clonorchis sinesis. Clonorchiasis is a known risk factor for the development of cholangiocarcinoma which is a neoplasm of the biliary system.Clonorchis sinensis is also known as a trematode. Trematoda is part of the phylum Platyhelminthes. Vertebrates are usually the host of adult trematode parasites. The interesting characteristic of these mostly hermaphroditic flukes is that they require one or more intermediate hosts. The first intermediate hosts are mollusks, without which miradicium (egg) development cannot occur. After a series of generations within the mollusk, large numbers of larvae are released - cercariae.



In the case of Clonorchis sinensis the cercaria penetrate the flesh of freshwater fish. When a person consumes the infected fish then the parasite moves to the biliary ducts.

Causes

Humans may be infected after ingesting metacercariae in poorly cooked fish. The characteristic findings of clonorchiasis were diffuse, mild dilation of the small intrahepatic bile ducts, particularly in the periphery of the liver. Fluke infections are diseases of the digestive tract and other organ systems that may be caused by several different species of Trematodes that have complex life cycles involving hosts other than human beings.

In human beings, fluke infections may be classified according to those diseases, that are caused by liver flukes and those caused by lung flukes.

Symptoms

The common symptoms are-

Fever

Chills

Anorexia

Diarrhea

Epigastric pain

Abdominal pain

Hepatomegaly

Treatment

First of all, the following diagnostic tests can help a victim be SURE that he or she is suffering from clonorchiasis. A medical history should be taken including questions on diet, travel, and regions where the patient has previously resided. A physical assessment will include gentle palpation of the liver. An Elisa blood test may be admistered.

Medical tests may include endoscopy and examination of a stool (faeces) sample for eggs. Radiological and sonographic assesments are also becoming increasingly popular, but different imaging modalities present various risks, including a high number of false positives. The adult fluke can also be recovered surgically.

There are a number of anthelmintic medications which work in different ways. Praziquantel or albendazole are the drugs of choice to manage clonorchiasis and of course treatment for the secondary effects of parasitemia may be necessary.

Albendazole is used to treat hydatid disease and larval taeniasis (beef tape worm) infection, and for some tapeworm infections by adult worms. It works by inhibiting metabolism in the cells of the worm, leading to their immobilization and death.

Praziquantel is used to treat blood flukes, lung flukes, liver flukes and intestinal flukes, and the majority of tapeworms. It is the drug of choice for treating clonorchiasis.