BILHARZIASIS Common Schistosomiasis Strains Comment Distribution Name of pathogen Genitourinary All Africa, Middle East and India Schistosomiasis Haematobium Intestinal All Africa, Brazil and most of Caribian Schistosomiasis Mansoni China, Philippen Schstosomiasis Japonicum Central Africa Schistosomiasis intercalatum Cambodia Schistosomiasis Mekongi

Egg Meracedium ← Snail Cercaria → → →

Female Schistosoma Male Schistosoma

BILHARZIASIS Definition: Chronic granulomatous inflammation caused by bilharzial infection, It is endemic in Egypt The granuloma is formed of macrophages, lymphocytes, plasma cells, eosinophils, giant cells, and fibroblasts

Life cycle of urinary bilharziasis: Caused by: Schistosoma hematobium. The life cycle Cercaria → skin → small vein → right side of the heart → lung → left side of the heart → Liver → maturation into adult worms →pass in blood to the urinary bladder (vesical venous plexus) → lay eggs → eggs pass with the urine → ovum hatch → miracidium → snail (intermediate host) → cercaria.

Pathogenesis The ovum retained in the bladder wall (submucosa) → granuloma formation chronic irritation & inflammation → epithelial changes → 1-Sandy patchs: healing of the granuloma by fibrosis → atrophy of the overlying epithelium 2- B ulcer 3-B polyp: epithelial hyperplasia

Bilharzial polyp

4-Brunn’s nests dipping of the transitional epithelium in the submucosa 5-Cystitis cystica : hydropic degeneration in Brunn’s nest→↓ 6-columner metaplasia of the transitional epithelium ↓ Cystitis glandularis 7- squamous metaplasia (Precancerous)

Squamous metaplasia of the urothelium

Bilharziasis, liver

Complications of urinary bilharziasis 1-Terminal hematurea → microcytic hypochromic anaemia 2-Bacterial infection 3-stone formation 4-Fibrosis (healing of B reaction) → difficulty in micturation → trabeculation of the bladder wall → stenosis of the bladder neck → hydroureter& hydronephrosis → renal failure 5- Squamous cell carcinoma

Intestinal bilharziasis Caused by schistosoma mansoni Life cycle: Cercaria → penetrate the skin → venous blood → Rt side heart → lung →Lt side of the heart → liver ( maturation into adult worms) → pass to rectal venous plexus → lay eggs → pass with stool → ovum hatch in water → miracidium → snail → cercaria

Pathogenesis: 1-( granuloma) : B ovum trapped in the intestinal wall (submucosa) → B inflammatory reaction 2-Sandy patch: healing of B reaction by fibrosis + calcification of the ovum with atrophy of the mucosa 3-Ulcers: necrosis of the mucosa 4-B polyp: epithelial hyperplasia overlying B granuloma 5- Fibrosis → narrowing of the intestinal lumen

Bilharziasis in the colon

Complications of intestinal Bilharziasis 1-Desentry 2-Blood in stool → microcytic hypochromic anaemia 3-Fibrosis → stenosis of the intestinal lumen + polyp → chronic intestinal obstruction

Bilharziasis of the liver Pathogenesis: 1-Impaction of the B ovum in the portal vein → deposited in portal tract → Granuloma → healing by fibrosis 2-Fatty change

Bilharzial granuloma

Bilharzial granuloma in the liver

3-Fine B fibrosis 4-Coarse B fibrosis

Complications of Bilharziasis in the liver 1-Portal hypertension → porto-systemic anastomosis → Splenomegally ascitis eosophageal varieces → hematemesis piles → bleeding per rectum 2-Hepatomegally 3-liver failure

Bilharzial splenomegally Pathogenesis: Hyperplasia of the reticuloendothelial system by B antigene Chronic venous congestion and portal hypertension

Microscopically: Hyperplasia of the lymphoid follicles, congestion of the sinusoids Thick capsule Fibrosis Interstitial hemorrhage Hyaline degeneration Atrophy of the follicles