Liver flukes

Fasciola species
Fasciola hepatica

1. Liver Flukes By: Pop Canata

2. Taxonomy Kingdom: Animalia Phylum: Platyhelminthes Class: Trematoda Subclass: Digenea (“two generations”) Order: Echinostomida Family: Fasciolidae Genus: Fasciola

3. Liver Flukes Fasciola species Found in the liver and biliary passages of humans and ruminants Fasciola hepatica Sheep liver fluke Temperate liver fluke Common Liver Fluke Fasciola gigantica Giant liver fluke Tropical liver fluke

4. Liver Flukes Fasciola hepatica Mode of transmission is by ingestion of metacercariae found in edible aquatic plants or by drinking water with floating metacercariae Metacercariae excsts in the duodenum or jejunum and liberate the juvenile fluke Juvenile fluke penetrates the intestinal wall and reaches the liver capsule The parasite burrows into the liver parenchyma where it grows and develops It becomes sexually mature in the bile ducts

5. Liver Flukes Fasciola hepatica Adult Worm Large, broad, flat body Leaf shaped Anterior end forms a prominent cephalic cone Small oral and ventral suckers Long and highly branched intestinal caeca

6. Liver Flukes Fasciola hepatica and gigantica

7. Liver Flukes Fasciola hepatica and gigantica First Intermediate Host : Lymnaea sp. Lymnaea philippinensis Second Intermediate Host Watercress grass

8. Liver Flukes Fasciola hepatica Fasciola hepatica Ova Large Hen’s egg shaped Ovoid Operculated Bile stained Unsegmented

9. Liver Flukes Fasciola hepatica Fasciola gigantica Ova Larger but very similar to Fasciola hepatica ova *Because of similarities, it is just safe to say Fasciola ova

10. Liver Flukes Fasciola species

11. Female adult: 25,000 eggs/day

12. Liver Flukes Fasciola hepatica Mode of transmission Ingestion of fresh water plants with metacercaria or by drinking water with floating metacercariae

13. Liver Flukes Fasciola species Diagnostic Stage Ova Infective Stage: Metacercaria

14. Liver Flukes Fasciola species Pathogenesis and Clinical Manifestations Fascioliasis Asymptomatic Can produce fever Right upper quadrant abdominal pain Hypereosinophilia Acute or invasive phase Migration from intestine to liver Traumatic and necrotic lesions in liver parenchyma Chronic or latent phase Asymptomatic Parasite has reached the bile ducts Obstruction Stimulates inflammation in the biliary epithelium leading to fibrosis Obstruction causes Biliary sepsis

15. Liver Flukes Fasciola species Diagnosis Microscopy -demonstration of eggs in the feces Serologic tests Low specificity because of cross reactivity with antigens of other parasites RFLP* PCR restriction Fragment Length Polymorphism * In molecular biology,  restriction fragment length polymorphism , or RFLP (commonly pronounced “ rif -lip”), is a technique that exploits variations in homologous DNA sequences. It refers to a difference between samples of homologous DNA molecules that come from differing locations of restriction enzyme sites, and to a related laboratory technique by which these segments can be illustrated.

16. Liver Flukes Fasciola species Treatment Bithionol 20-50 mg/kg body weight on alternate days to complete 10 to 5 doses Triclabendazole Also a recommended drug of choice due to: Efficacy Safety Ease of use

17. Liver Flukes Fasciola species Epidemiology Worldwide distribution Economic importance in livestock raising In the Philippines, the dominant species is Fasciola gigantica affecting cattle and water buffalos Few human cases are reported locally

18. Liver Flukes Fasciola species Prevention This can be accomplished by inspecting the plants, especially watercress, very carefully for the metacercariae or more effectively by not eating plants grown in areas where herbivorous mammals (especially sheep) are found. The contamination of water with feces from infected animals or people in areas where the aquatic plants are used for food should be prevented. Water-grown vegetables should be washed with 6% vinegar or potassium permanganate for 5-10 minutes, which kills the encysted metacercariae . This approach is more successful than attempts to halt the consumption of raw vegetables. Cook water-grown vegetables thoroughly before eating. Avoid sewage contamination of growing areas. Use of molluscicides is the most frequent public health intervention, as it prevents the transmission of many other trematodes , including  Schistosoma  spp. Treatment of animals to reduce the reservoir and reduce stock losses has been used. Until the introduction of single-dose triclabendazole , bithionol was the only available treatment, much limited by expense and treatment duration.