Clonorchis Health Dictionary

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Clonorchis: From 1 Different Sources

n. a genus of liver flukes, common parasites of humans and other fish-eating mammals in the Far East. The adults of C. sinensis cause clonorchiasis. Eggs are passed out in the stools and the larvae undergo their development in two other hosts, a snail and a fish.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Liver Disease In The Tropics

ACUTE LIVER DISEASE The hepatitis viruses (A– F) are of paramount importance. Hepatitis E (HEV) often produces acute hepatic failure in pregnant women; extensive epidemics – transmitted by contaminated drinking-water supplies – have been documented. HBV, especially in association with HDV, also causes acute liver failure in infected patients in several tropical countries: however, the major importance of HBV is that the infection leads to chronic liver disease (see below). Other hepatotoxic viruses include the EPSTEIN BARR VIRUS, CYTOMEGALOVIRUS (CMV), the ?avivirus causing YELLOW FEVER, Marburg/Ebola viruses, etc. Acute liver disease also occurs in the presence of several acute bacterial infections, including Salmonella typhi, brucellosis, leptospirosis, syphilis, etc. The complex type of jaundice associated with acute systemic bacterial infection – especially pneumococcal PNEUMONIA and pyomiositis – assumes a major importance in many tropical countries, especially those in Africa and in Papua New Guinea. Of protozoan infections, plasmodium falciparum malaria, LEISHMANIASIS, and TOXOPLASMOSIS should be considered. Ascaris lumbricoides (the roundworm) can produce obstruction to the biliary system. CHRONIC LIVER DISEASE Long-term disease is dominated by sequelae of HBV and HCV infections (often acquired during the neonatal period), both of which can cause chronic active hepatitis, cirrhosis, and hepatocellular carcinoma (‘hepatoma’) – one of the world’s most common malignancies. Chronic liver disease is also caused by SCHISTOSOMIASIS (usually Schistosoma mansoni and S. japonicum), and acute and chronic alcohol ingestion. Furthermore, many local herbal remedies and also orthodox chemotherapeutic compounds (e.g. those used in tuberculosis and leprosy) can result in chronic liver disease. HAEMOSIDEROSIS is a major problem in southern Africa. Hepatocytes contain excessive iron – derived primarily from an excessive intake, often present in locally brewed beer; however, a genetic predisposition seems likely. Indian childhood cirrhosis – associated with an excess of copper – is a major problem in India and surrounding countries. Epidemiological evidence shows that much of the copper is derived from copper vessels used to store milk after weaning. Veno-occlusive disease was ?rst described in Jamaica and is caused by pyrrolyzidine alkaloids (present in bush-tea). Several HIV-associated ‘opportunistic’ infections can give rise to hepatic disease (see AIDS/HIV).

A localised (focal) form of liver disease in all tropical/subtropical countries results from invasive Entamoeba histolytica infection (amoebic liver ‘abscess’); serology and imaging techniques assist in diagnosis. Hydatidosis also causes localised liver disease; one or more cysts usually involve the right lobe of the liver. Serological tests and imaging techniques are of value in diagnosis. Whilst surgery formerly constituted the sole method of management, prolonged courses of albendazole and/or praziquantel have now been shown to be e?ective; however, surgical intervention is still required in some cases.

Hepato-biliary disease is also a problem in many tropical/subtropical countries. In southeast Asia, Clonorchis sinensis and Opisthorchis viverini infections cause chronic biliary-tract infection, complicated by adenocarcinoma of the biliary system. Praziquantel is e?ective chemotherapy before advanced disease ensues. Fasciola hepatica (the liver ?uke) is a further hepato-biliary helminthic infection; treatment is with bithionol or triclabendazole, praziquantel being relatively ine?ective.... liver disease in the tropics

Cholangiocarcinoma

n. a rare malignant tumour of the *bile ducts. Clinical features include abdominal pain, weight loss, pruritus, obstructive jaundice, and abnormal liver function tests. A tumour located at the junction of the right and left hepatic ducts within the liver is known as a Klatskin tumour. Primary sclerosing *cholangitis, *ulcerative colitis, chronic infection with specific liver flukes (such as Clonorchis sinensis), and exposure to the imaging contrast agent Thorotrast are potential risk factors for the development of cholangiocarcinoma. Differentiation from other causes of bile duct *stricture(s), e.g. sclerosing cholangitis, can be very difficult.... cholangiocarcinoma

Clonorchiasis

n. a condition caused by the presence of the fluke Clonorchis sinensis in the bile ducts. The infection, common in the Far East, is acquired through eating undercooked, salted, or pickled freshwater fish harbouring the larval stage of the parasite. Symptoms include fever, abdominal pain, diarrhoea, liver enlargement, loss of appetite, emaciation and – in advanced cases – cirrhosis and jaundice. Treatment is unsatisfactory although *praziquantel has proved beneficial in some cases.... clonorchiasis

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