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bilharziasis bil·har·zi·a·sis (bĭl'här-zī'ə-sĭs)
group of chronic disorders caused by small, parasitic flatworms (family Schistosomatidae) commonly called blood flukes. Schistosomiasis is characterized by inflammation of the intestines, bladder, liver, and other organs. Next to malaria, it is probably humanity's most serious parasitic infection, affecting at least 200 million people yearly in Africa, Asia, South America, and the Caribbean. There schistosomiasis is most prevalent in rural communities in which standards of hygiene are low. The disease is ordinarily contracted by working, bathing, or swimming in water populated by snails that carry the worms. The parasites were first identified as a cause of the disease in the 1850s by Theodor Bilharz, a German pathologist working in Egypt.