Fascioliasis is a waterborne and foodborne zoonotic disease caused by two parasites of class Trematoda, genus Fasciola; namely F.hepatica and F. giganticaHumans are incidental hosts and become infected by ingesting contaminated watercress or water. The illness occurs worldwide, particularly in regions with intensive sheep or cattle production. Incidence of human infection has increased over the past 20 years.
Various symptoms like fever, nausea, vomiting, appetite loss, indigestion, abdominal pain, diarrhea, cough etc are seen generally.
Sheep, cattle and goats are the definitive hosts. Other alternate herbivore hosts are horses, pigs, buffaloes, donkeys and pigs. The adult worms reside in the biliary passages of these hosts and are shed in their stools.
Up to 17 million cases have been estimated to be affected with fascioliasis worldwide. F. hepatica typically occurs worldwide in temperate regions, except Oceania. F. gigantica causes outbreaks in areas of Ireland and Africa. Infection is most prevalent in regions with intensive sheep and cattle production. Miracidia require temperate water to develop and hatch.