Cris Scott and Angel Knopick

Liver rot and you! Until 1300 thought to be a leech From 1970 to 1995, about 300,000 cases were reported in 61 countries. 2.4 million are infected and 160 million more at risk 2009 evidence of an emerging problem? In regions of Bolivia, 38% of children ages 5 to 19 may be infected.

Classification/Taxonomy Kingdom: Animalia Phylum: Platyhelminthes Class: Trematoda Order: Echinostomida Family: Fasciolidae Genus: Fasciola Species: hepatica

Geographic Range WORLDWIDE! Human infections: Europe (especially France, Spain, Portugal), North Africa, South America (especially Bolivia), Cuba, United States Need temperate, slow-moving, or standing water urbanization

What is affected?? aka…HOSTS Definitive hosts: Sheep, cattle, buffalo, goats, and rabbits Intermediate hosts: Snail Fossaria modicella or Stagnicola bulimoides Accidental hosts: Humans??

Morphology Adult One of the largest flukes in the world Average is 30 mm long and 13 mm wide Leaf/cone shaped 1 posterior and 1 anterior sucker Egg Average 140 µm long and 75 µm wide

Life Cycle Eggs from human or other host are passed in feces: no embryo. Eggs are released into water: embryo. Eggs hatch and miracidia are released. Miracidia invade a snail (intermediate host). In the snail, the parasite undergoes three levels of development: Sporocyst, Rediae, and Cercariae. The cercariae are excreted from the snail and encyts as metacercariae on aquatic vegetation (lose tails). Cattle and sheep acquire the parasite by eating the vegetation containing the metacercariae. Humans normally become infected by eating contaminated watercress. The metacercariae excyst in the duodenum. The metacercariae migrate through the intestinal wall, the peritoneal cavity, and the liver into the biliary ducts They develop into adult flukes, and eggs are excreted in the feces.

Fascioliasis: infection by liver flukes Humans: Abdominal pain Fever Eye infection- blindness Jaundice Eosinophilia Diarrhea Hepatomegaly (enlarged liver) Skin rash Anemia Animals Acute Type I: > 5000 ingested metacercariae, quick death without clinical signs Acute Type II: metacercariae, slowly die Subacute: 800 – 1000 metacercariae, anemia, weight loss, and death, Chronic: 200 – 800 metacercariae, bottle jaw, emaciation, weight loss, and edema

Diagnosis Liver blockage coincides with the consumption of watercress Eggs in stool Fast-ELISA False results are possible when patients have eaten infected liver and F. hepatica eggs pass through the feces Liver free diet Early diagnosis is essential to prevent irreparable damage to the liver

Control and Treatment Avoid “wild” watercress Thoroughly cook liver Education on eating uncooked aquatic plants (kjosco) Control host reservoir populations Control snail populations Triclabendazole (drug of choice) & Rafoxanide

Vaccines Proteases secreted immunizing antigens Proteases/hemoglobin: egg viability reduced Cysteine proteases: worms reduced 75% ≠

Economic Importance Infection leads to mortality, reduction of milk and meat production Leads to secondary bacterial infections In Montana, 17% of cattle livers were infected In Mexico, over 400,000 out of 6 million cattle slaughtered were confiscated

References CDC: 15 Feb 2011http:// NIH: 15 Feb 2011http:// Wiki: 15 Feb 2011http://en.wikipedia.org/wiki/Fasciolosis WHO: No3/bulletin_1995_73(3)_ pdf, 15 Feb 2011http://whqlibdoc.who.int/bulletin/1995/Vol73- No3/bulletin_1995_73(3)_ pdf WHO: ascioliasis/en/, 15 Feb ascioliasis/en/ Roberts, Larry S., Gerald D. Schmidt, and John Janovy. Gerald D. Schmidt & Larry S. Roberts' Foundations of Parasitology. Boston: McGraw-Hill Higher Education, Print.