trmatodes

Trematodes (flukes):
Clonorchis sinensis (the Chinese or oriental liver
fluke)
This parasite is endemic in Japan ,Korea, China,
Taiwan and Vietnam.
Cause disease called clonorchiasis
Morphology :
Adult worm: C .sinensis is narrow ,oblong
,flat worm with pointed anterior end somewhat
rounded posterior end. it measures 10-20mm in
length by 3-4mm in breadth .The oral sucker is
slightly larger than ventral sucker. The blind
intestinal caeca are simple and extend to the
caudal region .It has two large branched testes.
these are situated one behind the other in the
posterior third of the body.
Eggs :
The eggs are broadly ovoid, have thick shell and are provided with distinct convex operculum resting on shoulders. A small knob is seen at the posterior end . they measure 28-35 ?m by 12-19 ?m(the smallest helminthes eggs). They contain ciliated embryos it is similar to eggs of H. heterophyes.
life cycle:
- Infective form: metacercaria encysted in flesh of fresh water fish
- Definitive host : man ,pig ,dog cat and rat.
- Intermediate host: 1st intermediate host is snail and 2nd intermediate host is fresh water fish.
- Infective mode: eating uncooked fish infected with metacercaria.
Clinical symptoms:
? Inflammatory reaction in the biliary epithelium of the bile ducts lead to fibrosis of the ducts.
? Biliary obstruction in heavy infection .
? Tender hepatomegaly.
? Epigastric pain.
Lab. diagnosis:
? Ova are found in faces and bile ducts or duodenal aspiration.
? String test.