Helminths > Trematodes > Liverfluke

Clonorchis sinensis

Clonorchis sinensis live in bile ducts of man, and is also called liver fluke. It cause disease named clonorchiasis.

1. Morphology

1.1 Adult 10~25 mm long Like sunflower seed grayish white Having 2 suckers

1.1 Adult

1.2 Egg The smallest egg Yellowish brown Having an operculum and a spine miracidium

An egg under electronic microscope

Eggs in feces

2. Life cycle

Miracidium

Sporocyst

Redia

Cercaria

Metacercaria

Important points Adults live in bile duct of man and other animals (cat and dog) Eggs are passed in feces Infective stage: metacercaria Intermediate host: snail and fish(shrimp) Adolescent: go into abdominal cavity first, and then invade bile ducts.

3. Pathogenesis and symptom

Pathogenesis • In early stage, adults cause inflammation of the bile ducts. • In late stage, the wall of the bile duct become thickened, the lumen become narrow.The eggs and dead worm form gallstones. At last, obstruction of bile duct will take place.

Pathogenesis Some trapped bile will flow back to hepatic tissues,and cause necrosis of hepatic cells. The necrotic hepatic cells become fibrotic. Several years later, cirrhosis of liver take place,hypertension of mesentery vein will appear as result.

Symptom In light infection: irregular appetite, diarrhea, abdominal pain, weakness, hepatomegaly, In heavy infection: Jaundice, abdominal pain, hepatomegaly, splenomegaly, ascites, bleeding of upper digestive tract, retarded growth, cancer of liver,etc.

Hepatomegaly and splenomegaly

Ascites and emaciation

Retarded growth

4. Diagnosis

5. Epidemiology

Distribution This disease is only distributed in Far East (Japan, China, korea, Laos, Thailand, Viet Nam, etc.)

Clonorchiasis in China

Factors for spread of this disease Sources of infection: infected persons, cat and other fish-eating animals. Modes of infection: ingestion of raw or half-cooked fish

6. Treatment and prevention Treat patients Praziquantel is of first choice. Control of fish-eating animals Management of night soil Eradication of snails Educate general population

CLASS-TREMATODES from bhushan in this class of phy helminths is unsegmented,flat,broad,resembling leaf of tree or flatfish. termatode name from they having large prominent suckers with ahole in middle (trema-hole, tode-appearance). Subclass digenea require two hosts.for definitive hosts in which they pass the sexual or adult stage r mammanls, & intermediate host in which they pass their asexual or larval stages r freshwater molluscs,snails.

FLUKES They r hermaphroditic except for schistosomesin which sex is separate.