Chronic urinary schistosomiasis

After about 2 months, the ova invade the bladder and ureter causing local inflammation. Initially asymptomatic, this may later cause frequency and haematuria. In heavy infection, haematuria may be gross and cause iron deficiency anaemia; in lighter infection, characteristically, haematuria occurs at the end of micturition.

Other features of chronic infection:

• calcified, contracted bladder - from calcification of ova
• bladder cancer - especially, squamous cell carcinoma
• hydro-ureter and hydronephrosis - from ureteric stricture and abnormalities of ureteric paralysis
• chronic pyelonephritis and pyonephrosis - from reflux nepropathy with bacterial superinfection; may cause renal failure and death
• less commonly, neurological symptoms from ectopic egg deposition in the spinal cord - usually, a transient paralysis