Schistosoma mansoni

Physiology and Structure

Resides in small branches of the inferior mesenteric vein near the lower colon.

The eggs are oval in shape and posses a sharp lateral spine.

 

 

 

 

Schistosoma mansoni egg

http://www.flickr.com/photos/ajc1/2693048966/

 

 

 

http://www.flickr.com/photos/15218842@N08/2370498968/

 

 

 

Clinical Syndromes

  •  Worms in the lungs may produce cough and upon reaching the liver, hepatitis may appear.
  • Flukes take up residence in the vessels and begin laying eggs. Upon doing so, fever, malaise and abdominal pain and tenderness of the liver may be observed.
  • Severe neurologic problems may follow when eggs are deposited in the spinal cord and brain.

 

 

Life Cycle:

 

Schistomes_LifeCycle.gif

 

taken from:  http://www.stanford.edu/class/humbio103/ParaSites2004/Schisto/Schistomes_LifeCycle.gif

 

 Treatment, Prevention and Control

  • Antihelminthic therapy may terminate oviposition (egg laying) but it does not afftect lesions caused by eggs which are already deposited in tissue.
  • Improved sanitation and control of human fecel deposits are critical in ensuring that the infection does not spread.