Dr.mustafa
surgery
Schistosomiasis
Schistosomiasis, also known as bilharzia, is a parasitic disease that leads to chronic ill health. It
is the major health risk in the rural areas. The worms responsible for the disease were
eventually discovered in 1851 by Theodor Bilharz,.
Pathogeneses:
Schistosoma haematobium causes urinary schistosomiasis and affects 54 countries in Africa and
the Eastern Mediterranean. People are infected by contact with water used in normal daily
activities. The cercariae are excreted by the snail into the surrounding water. They can
penetrate an individual's skin within a few seconds, continuing their biological cycle once they
have made their way to the victim's blood vessels. Within 30 to 45 days, the parasite is
transformed into a long worm which is either male or female. The female lays from 200 to 2000
eggs per day over an average of 5 years, according to the species.
In urinary schistosomiasis,
they live in the blood vessels of the bladder. Only about a half of the eggs are excreted in the
urine (urinary schistosomiasis). The rest stay in the body, damaging other vital organs. It is the
eggs and not the worm itself which cause damage to the intestines, the bladder and other
organs. There is an association between urinary schistosomiasis and a form of cancer of the
bladder in some regions
Bladder schistosomiasis:
After maturation, the adult worm pairs travel to the pelvic veins. Eggs are deposited in the
bladder wall vessels and incite a granulomatous response that results in polypoid lesions. The
eggs may go on to incite a chronic inflammatory response and fibrosis, which is an important
predisposing factor for squamous cell carcinoma.
Imaging Findings for Bladder schistosomiasis:
Imaging findings mirror the pathologic course.
1-In the acute phase, nodular bladder wall thickening is observed at urography or cross-
sectional imaging.
2-The chronic phase is characterized by a contracted, fibrotic, thick-walled bladder with
calcifications. These calcifications are typically curvilinear and represent the large numbers of
calcified eggs within the bladder wall. A mass may be secondary to inflammation or
complicating carcinoma, typically squamous cell carcinoma.
Dr.mustafa
surgery
Treatment:
Until the 1970's, treatment of schistosomiasis was nearly as dangerous as the disease itself.
Modern treatment is effective and without risk. Three new drugs have revolutionized
treatment.
Praziquantel - effective in the treatment of all forms of schistosomiasis, with virtually no side
effects
Oxamniquine - used exclusively to treat intestinal schistosomiasis in Africa and South America
Metrifonate - effective for the treatment of urinary schistosomiasis
By:TWANA NAWZAD