Schistosoma

Schistosoma /Schis·to·so·ma/ (-so´mah) a genus of blood flukes, including S. haemato´bium of Africa, S. japon´icum of East Asia, S. manso´ni of Africa, South America, and the West Indies, and S. intercala´tum of Central Africa. The invertebrate hosts are snails. Human infection (schistosomiasis) follows contact with contaminated water; flukes penetrate the skin, enter the bloodstream, and make their way to other organs.schistoso´mal

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Schis·to·so·ma (shst-sm, sks-)

n.

A genus of digenetic trematodes that includes the blood flukes of humans and domestic animals that cause schistosomiasis. Also called Bilharzia.

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Schistosoma

[shis′təsō′mə]

Etymology: Gk, schistos, cleft, soma, body

a genus of blood flukes that may cause urinary, GI, or liver disease in humans and that requires fecal contamination of water and freshwater snails as intermediate hosts. Schistosoma haematobium, found chiefly in Africa and the Middle East, affects the bladder, ureter, and pelvic organs, causing painful frequent urination and hematuria. S. japonicum, found in Japan, the Philippines, and Eastern Asia, causes GI ulcerations and fibrosis of the liver. S. mansoni, found in Africa, the Middle East, the Caribbean, and tropical America, causes symptoms similar to those caused by S. japonicum. Also called Bilharzia. See also schistosomiasis.

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Schistosoma [shis″-, skis″to-so´mah]

a genus of trematodes, including several species parasitic in the blood of humans and domestic animals. The organisms are called schistosomes or blood flukes. Larvae (cercariae) enter the body of the host by way of the digestive tract, or through the skin from contact with contaminated water, and migrate in the blood to small blood vessels of organs of the intestinal or urinary tract; they attach themselves to the blood vessel walls and mature and reproduce. The intermediate hosts are snails of various species.

The life cycle of Schistosoma. From Mahon and Manuselis, 2000.

Schistosoma haemato´bium a species endemic in North, Central, and West Africa and the Middle East; the organisms are found in the venules of the urinary bladder wall, and eggs may be isolated from the urine.

Schistosoma japo´nicum a species geographically confined to China, Japan, and nearby countries; found chiefly in the venules of the intestine.

Schistosoma manso´ni a species widely distributed in Africa and parts of South America; the organisms are found in the host's mesenteric veins, and eggs may be found in the feces.

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Schistosoma

a genus of elongated dioecious trematodes which inhabit blood vessels of the host. The eggs are found in the wall of the bladder, uterus and urethra. Includes S. bovis (ruminants), S. curassoni (ruminants), S. haematobium (humans), S. incognitum (pigs, dogs), S. indicum (ruminants, horses), S. intercalatum (humans, ruminants, horses), S. japonicum (humans, many other species), S. magrebowiei (ruminants, zebra), S. lieperi (wild artiodactyls), S. mansoni (humans, wild animals), S. mattheei (most species), S. mekongi (humans, dogs), S. nasalis (ruminants, horses), S. rodhaini (dogs, rodents), S. spindale (ruminants, dogs), S. suis (see S. incognitum, above).

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Schistosoma

Parasitology A genus of elongated sexually dimorphic trematodes, the blood flukes, of phylum Platyhelminthes, Class Trematoda, of which there are 3 major human pathogens: S hematobium, S japonicum, and S mansoni; Schistosoma spp infect ±200 million worldwide, kill 800,000/yr; morbidity is due to exuberant tissue reaction to the eggs–they don't replicate in humans. See Circumoval body, Pipestem fibrosis.