Schistosome: A parasitic trematode worm contracted from infested water that is capable of causing liver, gastrointestinal tract and bladder disease. There are three main species of these trematode worms (flukes) -- Schistosoma haematobium, Schistosoma japonicum, and Schistosoma mansoni -- that produce disease in humans. The larval forms of the para... Found on http://www.medterms.com/script/main/art.asp?articlekey=18309