This is a parasitic worm that
occurs throughout Asia and Europe. The worm has a
complicated life cycle, which results in human infection.
Snails ingest eggs from water contaminated by human or
animal feces. The eggs turn into larvae that leave the
snails, and then infect fish. The infected fish are then
eaten by humans, and cause infection. The infection in
humans spreads to the bile ducts (in the liver) and the