Schistosoma
 A genus of trematodes Schistosoma commonly known as blood-flukes are parasitic flatworms which are responsible for a highly significant group of infections in humans termed schistosomiasis. Schistosomiasis is considered by the World Health Organization as the second most socioeconomically devastating parasitic disease (after malaria) with hundreds of millions infected worldwide.Adult flatworms parasitize mesenteric blood vessels.