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Common name: Sheep Liver Fluke

Scientific name: Fasciola hepatica

Kingdom: Animalia

Phylum: Platyhelminthes

Class: Trematoda

Order: Echinostomida

Family: Fascioliclae

Geneus: Fasciola

Species: F. hepatica

The sheep liver fluke is a harmful parasite to humans, sheep, and cattle. Its life cycle begins as the eggs pass in feces, then the eggs go in water then attaching themselves to a snail. Once hatched in the snail three steps are then taken place in snail tissue. After that has occurred the parasite is free-swimming on water plants. Once the water plant is then digested by a human, sheep, or cow it becomes infectious in an organisms system. When the parasite is in the system it goes through the intestinal wall to the liver then to the biliary ducts for three to four months. The adult flukes are up to 30mm by 13mm. Human infections are found where sheep and cattle are raised, and where humans consume raw watercress.

The country’s in which this takes place is Europe, the Middle East, and Asia. While being infected with it the symptoms are abdominal pain, fever, vomiting, diarrhea, and others that can last for months. Treatment for this is triclabendazole with bithinol as an alternative. Since sometimes the parasite will not respond to praziquantel. The history of this parasite have been showing human infection as early as the Pharaonic times. It was first discovered in a sheep by a french man named Jehan de Brie. Not until the late 19th century that its life cycle was educated and its role to humans was recognized. Since then it has become one of the most studied infections, and holds a high-ranking position in the minds of the public health policy makers. In Ireland up to 45% of sheep and cattle are infected with this parasite. In recent years rates in Ireland have averaged 70-80%in adult cattle and sheep are infected with this parasite. Also an estimated 17 million people are infected with this parasite worldwide including Bolivia, Peru, Egypt, and Iran. Climate and weather effects are important to the parasite. 

No development of the parasite can occur if temperatures are under 100 degrees Celsius or above 260 degrees Celsius. Eggs need at least 0.2mm of moisture per month for development.

Author: Tiffany B

Published: 02/2008


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