What is Schistosomiasis

Schistosomiasis (bilharzia) Any one ofa group of diseases of humans and some other mammals caused by infestation by blood flukes (trematodes of the genus Sdiis-tosomo). The trematode requires two hosts; the first is an aquatic snail in which larvae emerging from eggs hatched in water de¬velop through several stages, finally to fork-tailed forms (cercariae] which escape from the snail, swim freely in the water, and attach themselves to and penetrate the skin of their second host, a mammal. In the mammalian body they move through blood vessels, feeding upon glyco-gen in the blood plasma and growing, eventually migrating to a site that varies from species to species, where they ma¬ture, mate, and lay eggs. The eggs leave the body in urine or faeces. Symptoms vary ac¬cording to the species causing the in¬festation, but may include swelling and tenderness of the liver, dropsy, enlarge¬ment of the spleen, watery skin eruptions, fever, cough, haemorrhage, diarrhoea, and reduced function of the affected organs. The diseases are common in low latitudes.