SCHISTOSOMIASIS OF BLADDER/ SNAIL FEVER/ BILHARZIASIS/ BILHARZIA/ KATAYAMA FEVER

•  Schistosomiasis is an infection with Schistosoma haematorium (parasitic worm)
• 5 species of schistosoma are-

i) S. Haematorium

ii) S. Mansoni

iii) S. Japonium

iv) S. Mekongi

v) S. Intercalatum

LIFE CYCLE-

• Man is the only definitive host and intermediate host is snail.
• Life cycle begins with the passage of eggs (4-6 weeks) into freshwater through urine.
• When the eggs are hatched, ,iracidia are produced and penetrates snail from cercarie.
• Eggs –> Miracidium –> cercaria (infects human) –> migrate to vesical venous plexus for reproduction –> eggs in urine

PATHOLOGY-

• Schistosoma eggs are highly antigenic and induces intense granulomatous reaction ain the bladder results in bladder fibrosis with ureteric or urethral fibrosis.
• Calcification of dead eggs within the bladder produces calcified bladder or bladder stones.
• Schistosoma is a genus of trematodes, commonly known as blood flukes.

CLINICAL FEATURES-

• After penetration of the skin, urticaria lasting about 5 days can occur (swimmer’s itch) is the first clinical sign from cercarial penetration.
• After intubation period of 4-12 weeks, Katayama syndrome (acute schistosomiasis) which is fever, urticaria, muscle ache, abdominal pain, cough, lymphadenopathy, hepatosplenomegaly, sweating and asthma with leuckocytosis and eosinophilia.
• MC symptom of urinary schistosomiasis is urinary frequency.
• Chronic Schistosomiasis is due to egg deposition.
• After an asymptomatic phase, there is painless terminal haematuria.
• Intestinal symptoms- abdominal pain and diarrhoea
• Urinary symptoms- urinary frequency, dysuria, hematuria.

INVESTIGATIONS-

1. Urine examination shows presence of eggs.
2. Cystoscopy-

a) Bilharzial pseudotubercles are the earliest specific appearance of disease

b) Bilharzial nodules caused by fusion of tubercles

c) Sandy patches– calcified dead ova

d) Ulceration- sloughing of mucous membrane containing dead ova

e) Fibrosis- secondary infection

f) Granulomas- aggregation of nodules

g) Papilloma

h) Carcinoma

1. IVU, RGV or cystography shows decrease bladder capacity
2. Plain radiographs shows-

a) Calcification in the wall of bladder (fetal head appearance)

b) Calcification of distal ureters- linear or pattern calcification characteristic feature.

TREATMENT-

• Praziquantel is DOC
• Metrifonate, oxaminiquine
• Surgical intervention for ureteric stricture or bladder thickening

COMPLICATIONS-

• Squamous bladder cancer