- Disease: Fascioliasis.
- Geographical distribution: Worldwide including Egypt.
- Habitat: Bile ducts.
- DH: Man or sheep or cattle (RH) .
- IH: Water snail, Lymnaea cailliaudi (F. gigantica) , Lymnaea truncatula (F. hepatica)
Morphology of Fasciola gigantica and hepatica :
F.gigantica Adult Worm.
- Larger 2-8 cm
- Less developed shoulders
- Parallel lateral borders.
- Larger ventral sucker
F.hepatica Adult Worm
- 2-3 cm
- Well apparent shoulders.
- Converging lateral borders
- Medial branches of intestinal caeca are small knobs
Life cycle of Fasciola species :
- Eggs pass with faeces to water. Egg develops miracidium and hatches. Miracidium enter snail and develops to sporocyst, redia and leptocercous cercaria (simple tail). Cercaria attaches to grasses and loses tail and forms encysted metacercaria.
- Infective stage: encysted metacercaria on grass or water.
- Mode of transmission is by ingestion of metacercaria found in raw unwashed grass or by drinking of contaminated water.
- Metacercaria excysts in the small intestine and penetrates the intestinal wall to peritoneal cavity and pierces the liver capsule and tissue to settle into the bile ducts to become adults.
Diagnosis :
I. Clinical diagnosis: Clinical picture
II. Laboratory:
1- Stool examination for egg (diagnostic stage).
It is useful in diagnosis of chronic fascioliasis, because adults are not yet developed and eggs are not yet excreted in the acute stage
** False diagnosis may result from eating infected raw liver where ova appears in stool. It can be avoided by preventing patient from eating liver for few days, then repeat examination if egg is still present, then patient is infected with Fasciola.
Treatment :
- Triclabendazole: 10 mg/ kg body weight single oral dose.
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