Schistosoma

Jump to: navigation, search
Schistosoma
Schistsoma mansoni egg
Schistsoma mansoni egg
Scientific classification
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Trematoda
Subclass: Digenea
Order: Strigeidida
Family: Schistosomatidae
Genus: Schistosoma
Weinland, 1858
Species

S. mansoni
S. japonicum
S. mekongi
S. intercalatum
S. haematobium
S. indicum
S. nasale
S. leiperi
S. malayensis
S. rodhaini

WikiDoc Resources for Schistosoma

Articles

Most recent articles on Schistosoma

Most cited articles on Schistosoma

Review articles on Schistosoma

Articles on Schistosoma in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Schistosoma

Images of Schistosoma

Photos of Schistosoma

Podcasts & MP3s on Schistosoma

Videos on Schistosoma

Evidence Based Medicine

Cochrane Collaboration on Schistosoma

Bandolier on Schistosoma

TRIP on Schistosoma

Clinical Trials

Ongoing Trials on Schistosoma at Clinical Trials.gov

Trial results on Schistosoma

Clinical Trials on Schistosoma at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Schistosoma

NICE Guidance on Schistosoma

NHS PRODIGY Guidance

FDA on Schistosoma

CDC on Schistosoma

Books

Books on Schistosoma

News

Schistosoma in the news

Be alerted to news on Schistosoma

News trends on Schistosoma

Commentary

Blogs on Schistosoma

Definitions

Definitions of Schistosoma

Patient Resources / Community

Patient resources on Schistosoma

Discussion groups on Schistosoma

Patient Handouts on Schistosoma

Directions to Hospitals Treating Schistosoma

Risk calculators and risk factors for Schistosoma

Healthcare Provider Resources

Symptoms of Schistosoma

Causes & Risk Factors for Schistosoma

Diagnostic studies for Schistosoma

Treatment of Schistosoma

Continuing Medical Education (CME)

CME Programs on Schistosoma

International

Schistosoma en Espanol

Schistosoma en Francais

Business

Schistosoma in the Marketplace

Patents on Schistosoma

Experimental / Informatics

List of terms related to Schistosoma

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

A genus of trematodes, Schistosoma spp., commonly known as blood-flukes and bilharzia, cause the most significant infection of humans by flatworms (schistosomiasis) and are considered by the World Health Organization as second in importance only to malaria, with hundreds of millions infected worldwide. Adult worms parasitize mesenteric blood vessels. Eggs are passed through urine or feces to fresh water, where larval stages can infect a new host by penetrating the skin.

Taxonomy

There are four species of schistosome which are infective to humans:

  • S. japonicum whose common name is simply blood fluke is found widely spread in Eastern Asia and the southwestern Pacific region. In Taiwan this species only affects animals, not humans. Freshwater snails of the Oncomelania genus are an important host for S. japonicum.
  • S. mekongi is related to S. japonicum and affects both superior and inferior mesenteric veins. S. mekongi differs in that it has smaller eggs, a different intermediate host, and longer prepatent period in the mammalian host.
  • S. haematobium, commonly referred to as the bladder fluke, originally found in Africa, the Near East, and the Mediterranean basin, was introduced into India during World War II. Freshwater snails of the Bulinus genus are an important host for this parasite.


S. indicum, S. nasale, S. leiperi are all parasites of ruminants.

Morphology

Adult schistosomes share all the fundamental features of the digenea. They have a basic bilateral symmetry, oral and ventral suckers, a body covering of a syncytial tegument, a blind-ending digestive system consisting of mouth, oesophagus and bifurcated caeca; the area between the tegument and alimentary canal filled with a loose network of mesoderm cells, and an excretory or osmoregulatory system based on flame cells. Adult worms tend to be 10-20 mm long and use globins from their hosts' hemoglobin for their own circulatory system.

Reproduction

Unlike other trematodes, the schistosomes are dioecious - i.e., the sexes are separate. The two sexes display a strong degree of sexual dimorphism, and the male is considerably larger than the female. The male surrounds the female and encloses her within his gynacophoric canal for the entire adult lives of the worms, where they reproduce sexually.

Related Chapters

External Links

cs:Schistosoma de:Pärchenegel



Linked-in.jpg