Blood trematode (Schistosoma haematobium) is a flatworm from the cluster of digenetic trematodes. Usually, the definitive host is human. In the human body, the parasite can live from 5 to 18 years. Blood trematode causes schistosomiasis or bilharciosis. The adult form of flatworm lives in blood vessels, where it feeds on blood. The male Schistosoma trematode measures 7-10 mm in length and 1 mm in width. It is covered with nodules and has a gynaecophoric duct in which the female is wrapped up.
Human infection occurs by penetrating the skin by the flatworm during bathing in contaminated water (fresh water reservoirs). Flatworms get through the blood vessels to the heart, then through the lungs (within 48 hours) into the portal vein system, where they reach sex maturity. Worms live 2-18 years. Skin symptoms usually occur in two stages. In the first stage (invasion), there appears an itching and papular rash at the site of skin penetration. In the second stage, urticaria and swelling of the face occurs. Adult worms migrate in pairs, in the circulatory system, the females lay eggs in the capillaries of the bladder, from where they are expelled outside.