Classification Kingdom : Animalia Phylum : Platyhelminthes Class : Trematoda Subclass : Digenea Order : Echinostomida Suborder : Distomata Family : Fasciolidae Genus : Faciola Species : F.hepatica

Fasciola hepatica The common name of this parasite, the "sheep liver fluke," is somewhat misleading since this parasite is found in animals other than sheep (including cattle and humans), and the parasite resides in the bile ducts inside the liver rather than the liver itself

Fasciola hepatica Morphology •Adult worm-it is a large leaf-shaped fluke, measuring 3cm in length by 1.5 cm in breadth and brown to pale grey in color. •There are two suckers, the oral sucker is smaller. •The anterior end bearing the oral sucker forms a conical projection. •The posterior end is rounded. •The acetabulum is situated in a line with the two shoulders formed by the broadening of the conical projection posteriorly.

Immature eggs are discharged in the biliary ducts and in the stool .   Eggs become embryonated in water , eggs release miracidia , which invade a suitable snail intermediate host.  In the snail the parasites undergo several developmental stages (sporocysts , rediae , and cercariae ).  The cercariae are released from the snail and encyst as metacercariae on aquatic vegetation or other surfaces.  Mammals acquire the infection by eating vegetation containing metacercariae.  Humans can become infected by ingesting metacercariae-containing freshwater plants, especially watercress . 

After ingestion, the metacercariae excyst in the duodenum and migrate through the intestinal wall, the peritoneal cavity, and the liver parenchyma into the biliary ducts, where they develop into adults .  In humans, maturation from metacercariae into adult flukes takes approximately 3 to 4 months.  The adult flukes (Fasciola hepatica: up to 30 mm by 13 mm; F. gigantica: up to 75 mm) reside in the large biliary ducts of the mammalian host.  The migration of the worms through the host's liver, and the presence of the worms in the bile ducts, are responsible for the pathology associated with fascioliasis

Diagnostic Stage Egg The largest egg in trematodes. Operculated containing immature miracidium. Eggs hatches in fresh water after 2-3 weeks

Symtoms Acute Phase ­ The acute phase of infection is rarely seen in humans and occurs only when a large number of metacercariae are ingested at once. Fever, tender hepatomegaly, and abdominal pain are the most frequent symptoms of this stage of infection although vomiting, diarrhea, urticaria (hives), anemia,The infection results in upper quadrant pain, chills

In children, severe anemia is a common result of infection and is the greatest source of disability from infection in this age group. These symptoms reflect the biliary obstruction and inflammation caused by the presence of the large adult worms and their metabolic waste in the bile ducts. Inflammation of the bile ducts eventually leads to fibrosis and a condition called "pipestem liver", a term describing the white appearance of the biliary ducts after fibrosis. The final outcome of severe infections is portal cirrhosis and even death.

Pathology 1- The parasite causes thickening of the lining of the bile duct and an inflammatory response in the surrounding liver tissue. 2- In heavy infections the bile duct epithelium can also be eroded, and the parasite's eggs will enter the liver tissue; in such cases the eggs are surrounded by a fibrotic capsule (granuloma). 3- Heavy infections can also result in stenosis (narrowing or blockage) of the bile ducts. Since the parasites can live for years and the number of parasites tends to increase as a person ages, the damage to the liver and bile duct tends to accumulate over time and can result in death.

Diagnosis This is based on the finding of eggs in stool or in the bile obtained by duodenal intubation. •Patients may be symptomatic during the first weeks of infection, but no eggs will be found in the stool until the worms mature, which takes 8 weeks. •Multiple stool examinations may be needed to detect light infections. •Moderate to high eosinophilia

Diagnosis A variety of immunological tests have been used •ELISA is a sensitive and practical method. •It becomes positive within 2 weeks of infection and becomes negative after treatment. •Antigen from adult worm is used for complement fixation test and skin test.

Treatment •F.hepatica is not sensitive to Praziquentel and treatment remains problematic. •Bithionol is now the drug of choice for fascioliasis. •Triclabendazole as a single dose is also

Fasciolasis (liver rot) Continue Name: Fasciola hepatica Fasciola gigantica Definition:- Sheep liver flukes Description: Short worm with wide shoulders. Long worm with narrow shoulders. Distribution: Latin America, Africa , Europe & China Egypt , Africa & Far East Disease: Fasciolasis (liver rot)

Adult lives in bile duct Human, sheep and cattle Fasciola hepatica Fasciola gigantica Habitat: Adult lives in bile duct Definitive host: Human, sheep and cattle ( Human is an accidentally definitive host) 1st intermediate host: Lymnaea trunculata Lymnaea cailliaudi 2st intermediate Aquatic plants & vegetables leaf blades Reservoir: Sheep & cattle

Continue It is leaf shape with a cone-shaped projection at the anterior end.  Living specimens are a grayish-brown in color

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