1. SAM GIRLS COLLEGE, BHOPAL
DEPARTMENT OF LIFE SCIENCES

2. Presented by Mrs. Ashwini Wao Asst. Prof. Life Science Department
Fasciola hepatica
Presented by
Mrs. Ashwini Wao
Asst. Prof.
Life Science Department

3. Scientific Classification
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Trematoda
Subclass: Digenea
Prder Echinostomida
Family: Fasciolidea
Genus: Fasciola
Species:hepitica

4. General Information
Commonly known as liver fluke
A parasitic flatworm

5. Geographical Distribution
Found in Rural areas of temperate and tropical regions
Especially located in regions with cattle and sheep herding
Found on every continent with nearly 180 million people at risk and an estimated 2.4 million people already infected worldwide.

6. Transmission
Occurs through the ingestion of raw, fresh water vegetation
Plants become exposed to the metacercariae when the body of water that the vegetation is growing in becomes contaminated by eggs in the fecal mater of the infested host
- A form of infection known as halzoun (in the Middle East) is contracted by eating the raw liver of an infected animal

7. Morphology Adult has a flat leaflike body
About mm long by 8-15 mm wide
Has an anterior elongation where oral and ventral suckers are located
Intestines are very branched

8. Hosts
- Cattle
Sheep
Sometimes humans

9. Life Cycle

10. Life Cycle (Cont’d)
The adult F. hepatica lives in bile ducts of the host’s liver
Begin to produce eggs 2-4 months after initial infection
Eggs pass down the bile duct through gastrointestinal tract and are released in the hosts feces
Require water of temperature above 10 C to hatch
The egg hatches and releases miracidiae within two weeks
These newly hatched miracidiae must find a Lymanae snail host within 24 of hatching or they will die

11. Life Cycle (Cont’d)
Inside the Lymanaea miracidium loses its cilia and develops into a sporocyst
Each sporocyst develops into a ridia which then burst the sporocyst and migrate to the hepato-pancreas of the snail
Ridia then develop into cercariae
Cercariae attach to plant matter and encyst, forming metacercariae which is the infective form of the fluke
Mammalian host consumes the vegetation with the metacercariae which then excyst in the small intestine

12. Life Cycle (Cont’d)
Metacercariae burrow through the intestinal wall, move through the peritoneal cavity and enter the liver parenchyma
Immature flukes migrate through the liver patanchyma for 6-8 weeks giving rise to acute symptoms
Once mature they settle in the bile ducts and begin to produce their own eggs after about a month.

14. Four Symptomatic Patterns
Acute Phase
Cronic Phase
Halzoun
Ectopic Infection

15. Acute Phase Rarely seen in humans
Fever, tender hepatomegaly, and abdominal pain are frequent symptoms.
Vomiting, diarrhea, and anemia may also be present

16. Cronic Phase More common in human population
Symptoms include: bilary cholic, abdominal pain, tender hepatomegaly, and jaundice
In children: severe anemia is common
Inflammation of the bile ducts eventually leads to fibrosis and a condition called “pipestem liver”
Severe infections can lead to death

17. Halzoun & Ectopic Infection
Occurs when an individual consumes infected raw liver
The adult worms can cause considerable pain, edema, and bleeding that can interfere with respiration
Adults can live in biliary ducts and cause symptoms for up to 10 years.
- In frequent, but can occur in peritoneal cavity, intestinal wall, lungs, subcutaneous tissue, and very rarely in other locations.

18. Diagnostic Tests
Most widely used form of diagnosis is the directly observed presence of F. hepatica eggs either in a stool sample, duodenal aspirate or biliary aspirate
Flukes do not begin to produce eggs until about 4 months after infection, so you cannot test the stool
Prior to 4 months: serological tests can be used
FAST-ELISA (most popular)
Ultrasound can be used to visualize adult flukes in the bile ducts
CT scan can reveal burrow tracts made by the worms

19. Treatment
Many countries use a 5-10 day course of oral bithionol at 30mg/kg body weight
Triclabendazole is a preferred antihelmintic agent, but is unavailable in most countries.
The resistance is rising to this drug
Along with pharmaceutical therapy, surgery may be necessary in very extreme cases to clear the biliary tract

20. Control Methods Education
Molluscicides: application of malluscicides to decrease the population of Lymnaea snails
Chemotherapy

21. Review Questions 1. What is the average size of an adult F. hepatica?
20 mm x 5mm
30 mm x 13 mm
10 mm x 5 mm
2. What continent can F. Hepatica be found?
Africa
Asia
America
All of the above

22. Review (Cont’d)
3. What is the most effective way to treat fascioliasis?
a. bithionol
b. flagyl
c. triclabendazole

23. References
“Fascioliasis” Retrieved: 2/19/2007
“Fasciola hepatica.” Wikipedia, free encyclopedia. Retrieved: 2/19/2007
“Fasciola hepatica.” Retrieved: 2/19/2007