Genitourinary Schistosomiasis

Diagnosis

  • Diagnosis of infection
    • Urine sediment reveals terminally spined eggs of S. haematobium (midday urine sample is most diagnostic)
    • Rectal or bladder mucosal biopsy to look for eggs
    • Serologic tests are not yet completely reliable. However, the new and developing DNA probes may become useful in the future for the diagnosis
  • Diagnosis of sequelae and complications
    • Plain x-ray of abdomen classically reveals bladder calcification. Seminal vesical, urethral, and distal ureteral calcification may be seen
    • IVU is essential to look for obstructive uropathy. More recently, CT scanning and ultrasound have been employed for the detection of obstructive and destructive lesions
    • Cystoscopic appearance

Medical management

  • S. haematobium is sensitive to metrifonate (Bilharcil), praziquantel (Biltricide), hycanthone mesylate (Etrenol), niridazole (Ambilhar), and Oltipraz
  • Praziquantel, a heterocycline prazinoisoquinoline
    • Drug of choice for treatment of all species
    • Dosage for S. haematobium is 40 mg/kg by mouth in single dose
  • Metrifonate (7.5 to 10 mg/kg)
    • Drug of choice for endemic infections caused by S. hematobium
    • Dosage is given in three oral doses at 14-day intervals
  • Niridazole (Ambilhar) is a nitrofuran
    • Dosage is given orally in two divided daily doses of 25 mg/kg per day for 5 to 7 days.
  • These drugs may have many side effects, and in edemic areas the clinician must be cognizant of risk-benefit ratios, as low-level infection is well tolerated by many persons and generally will not produce symptomatic chronic disease or chronic obstructive uropathy

Surgical management

  • Surgical procedures are reserved for complications of infection such as:
    • Ureteral stenosis
    • Bladder fibrosis
    • Bladder carcinoma
  • Procedures include:
    • Ureteral dilatation
    • Ureteral reimplantation
    • Partial cystectomy
    • Bladder augmentation
    • Cystectomy with urinary diversion

References


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