Bilharziasis is an indemic parasite disease in Egypt caused by Schistosoma hematobium and schistosma mansoni.
The infective stage (cercaria) enters the body by piercing the skin. The adult warm lives & matures in the portal vein.
This worm then migrates to lay its ova. The ova deposited become surrounded by bilharzial granulation tissue made of lymphocytes, plasma cells, foreign body giant cells and eosinophils (bilharzial granulation tissue). The lesion ends in fibrosis.
Urinary bladder Bilharziasis
It is caused mainly by S. hemarobium and affects mainly the trigone of urinary bladder and around ureteric orifices.
a) Congestion and granularity.
b) Sandy patches: irregular dirty yellowish patch due to shining of heavy deposits of calcified ova through thinned or atrophied mucosa.
c) Bilharzial polypi: rare.
d) Bilharzial ulcers: occur due to continuous piercing of the ova, atrophy of the mucosa or after casting of a polyp.
Complications of urinary bilharziasis:
1 – Terminal hematuria and anemia.
3- Fibrosis of bladder neck leading to urinary retention or around ureteric orifices causing hydroureter and hydronephrosis.
4- Renal stones.
5- Carcinoma of urinary bladder.
It is mainly caused by S. mansoni. The rectum is the commonest site, then it diminishes in severity proximally to become very rare in the small intestine.
Lesions: one a more of the following lesions may appear
1- Hyperaemia and granulanity: are not very well apparent because the intestinal mucosa is thick.
2- Bilhazial ulcers: are more common and usually larger than those of the urinary bladder.
3- Sandy patches: are less common.
4- Bilhanzial polypi: are common, particularly in the rectum and sigmoid colon. The mucosa is elevated, then pushed towards the lumen, carrying with it a central vascular core of fibrous tissue containing the ova and bilharzial granulation tissue. The mucosa in thickened due to reactive hyperplasia.
The polyps are usually multiple, sessile or pedunculated. Torsion of a polyp may occur with cut of blood supply leading to necrosis of the polyp which falls down leaving an ulcer.
Complications of intestinal bilharziasis:
1) Bilharzial dysentery with diarrhea, tenesmus, blood and mucous.
2) Intestinal hemorrhage which is prolonged leading to hypochomic anemia.
3) Pericolic bilhazioma which is a tumor-like mass formed of bilharzial granulation tissue and is usually misdiagnosed as cancer colon.
4) Chronic intestinal obstruction is rare due to a localized is band of fibosis.
5) Closed bilharzial lesion in which marked fibrosis blocks the way for the freshly coming ova, which pass into the portal circulation as emboli to produce bilharziasis of the liver.
Bilharziasis of liver
There is often massive fibrosis around major portal tracts leading to portal hypertension.
It is due to fibrosis and arterio-venous shunting. This may be manifested as:
3- Varices due to opening of porto-systemic shunts
a- At the lower third of esophagus forming esophageal varices.
b- Around the umbilicus forming caput medosa. c- Around the anus forming piles. 4- Hepatic failure.