Schistosoma species

• Infection with a species of the genus Schistosoma

Species

• Schistosoma mansoni: liver and gut
• Schistosoma haematobium: GU/pelvis
• Schistosoma japonicum: liver and gut
• Schistosoma 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 given over one day split into 3 doses
• Chronic
  • Praziquantel 20-40 mg/kg or 40-60 mg/kg (if at risk for S. japonica)
  • Given over one day split into 3 doses, then repeated 6 weeks later

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