Fasciola Species PDF - Helwan University

Fasciola Species by Dr. Shaimaa Helmy Ass. Professor of Medical parasitology Faculty of Medicine Helwan University Fasciola hepatica and Fasciola gigantica Liver fluke  Objectives By the end of this lecture...

Fasciola Species by Dr. Shaimaa Helmy Ass. Professor of Medical parasitology Faculty of Medicine Helwan University Fasciola hepatica and Fasciola gigantica Liver fluke  Objectives By the end of this lecture, you will be able to: Recognize Fasciola hepatica and gigantica regarding their: Geographical distribution Life cycle Mode of infection Pathogenesis Clinical picture Diagnosis Treatment Prevention and control Define spurious infection and differentiate between it and true fascioliasis. Define Parasitic Pharyngitis or Halzoun  Fasciola species Geographical Distribution: Worldwide F. gigantica cattle raising countries F. hepatica sheep raising countries Both exist in Egypt causes Fascioliasis  Life Cycle of Fasciola Infected Man (DH) Infected Herbivorous Mode of infection animals (RH) Ingestion of contaminated vegetables & water Habitat (Bile ducts of the liver) Egg in stool Encysted metacercaria (ID) (DS) Fresh water Lepto-cercous L. cailliaudi L. truncatula cercaria Snail (IH)  Pathogenesis Penetration of small intestine by excysted metacercariae to reach peritoneum Destruction and necrosis of liver parenchyma by migrating immature flukes leading to inflammatory reactions and haemorrages Obstruction of bile ducts: 1. Mechanical 2. Inflammation 3. Proline excreted by the flukes → Hyperplasia of biliary epithelium and fibrous thickening of the ducts → obstruction Periductal fibrosis and pressure atrophy on adjacent liver tissue  Pathogenesis (cont.) Secondary bacterial infection with manifestations of hepatitis Minute abscesses form around eggs trapped in the parenchyma Liver cirrhosis could occur with severe Fasciola infection Flukes may lose way and form ectopic lesions  Clinical Picture Light infection could passed unnoticed & Spontaneous healing may occur Digestive disturbances and diarrhoea. Fever, urticaria, bronchial asthma Due to Allergic reaction to parasite byproducts Pain & tenderness in the right costal margin and substernal pain (the right hypochondrium). Enlarged tender liver (hepatomegaly). Cholangitis, cholecystitis and obstructive jaundice.  Diagnosis of Fascioliasis I) Clinically (suggestive): Fever & Hepatomegaly & High Eosinophilia II) Laboratory: 1- Stool Examination or duodenal aspirate 2- Immunological tests 3- Blood examination III) Radiologically  Laboratory Diagnosis I) Stool Examination or duodenal aspirate: for Detection f eggs S: 140 X 70 µ S: oval, operculated, thin shelled C: yellowish C: immature ovum  Laboratory Diagnosis (cont.) Diagnosis of Fascioliasis by stool analysis is of limited use Why? Because: 1- eggs appear in stool after 3-4 months. (prepatent period) 2- eggs are not detectable in the chronic phase. 3- eggs appear in stool of uninfected persons after eating cooked liver of infected animal. (Spurious infection – false fascioliasis)  Laboratory Diagnosis (cont.) II-Immunodiagnostic tests: To detect Fasciola antigen in stool (copro-antigen) or antibody in serum by Enzyme-liked immunosorbent assay (ELISA) Immunofluorescence assay Immuno-electrophoresis It can detect early prepatent and chronic infections  Laboratory Diagnosis (cont.) III- Blood Examination High eosinophilia Anaemia (up to 80%)  Radiological diagnosis Radiological imaging Dye is injected through the needle Percutaneous cholangiography Ultrasonography  Radiological diagnosis (cont.) Endoscopic retrograde cholangiography  Treatment Triclabendazole single oral dose of 10 mg / Kg / b. w. single oral dose is effective. Bithionol (Dichlorophenol) 30 - 50 mg / Kg every other day for ten doses.  Prevention and Control - Mass treatment - Proper washing or cooking of aquatic vegetations - Soaking of vegetables in vinegar or potassium permanganate - Safe water supply - Snail control  Parasitic Pharyngitis or Halzoun Ingestion of fresh RAW sheep, goats and rabbits livers infected with living Fasciola worms Inflammation of pharyngeal mucosa may result in suffocation Treatment of Halzoun: Gargling with alcoholic drinks, emetics. Tracheostomy. Control of Halzoun: Proper cooking of animals tissue.