Once they reach the liver, they move around the liver for up to six weeks, feeding on liver tissue, until they reach the bile ducts where the worms mature into adults. The miracidia swim around until they encounter suitable snail intermediate hosts to infect, or they die within 24 hours. Suitable vectors are aquatic or amphibious snails of the Lymnaeidae family. After the miracidia infect snails, they undergo asexual multiplication, producing several thousand cercariae over several weeks. The cercariae are released into fresh water.
Aquatic plants associated with the fascioliasis infection are watercress and water caltrop.
Definitive hosts eating uncooked aquatic plants and vegetation with encysted metacercariae are infected, starting the cycle over again. The appearance of symptoms as well as the severity of the disease will depend on the intensity of infection and the host. Symptoms may appear a few days after ingestion of larvae, when the immature worms reach the abdominal cavity and begin migrating across or in the liver. These symptoms may be related to lesions in the abdominal cavity and the liver during the acute phase of the infection. Typical symptoms during this phase may include fever, abdominal pain, other gastrointestinal disturbances and urticaria.