Schistosoma

Schistosoma spp. (schistosomiasis)

Definition

• Infection with a species of the genus Schistosoma

Species

• S. mansoni: liver and gut
• S. haematobium: GU/pelvis
• S. japonicum: liver and gut
• S. mekongi: Mekong basin

Risk Factors

• Fresh water exposure in endemic countries

Investigations

• Labs
  • CBC, showing eosinophilia
  • Schisto serology (only positive 6 weeks after infection)
  • Egg detection in stool, urine, semen, or tissue biopsy
• Imaging
  • Eggs can cause granulomatous disease in various organs
  • Bladder polyps and obstruction may be seen on ultrasound

Management

• Acute
  • Praziquantel 40mg/kg/d
    • Can cause nausea, dizziness, and fever
• Chronic
  • Prevention

Prognosis

• Increased risk of squamous cell carcinoma, which increase with young age at infection, duration of infection, high burden of infection, and bladder wall fibrosis