Schistosomiasis (=bilharzia) is an intravascular infection caused by the parasitic trematode worms schistosoma. It is carried by freshwater snails which release cercariae (=parasitic larvae). Human infection occurs after contact with water containing cercariae, for example after swimming. 

Schistosomiasis is common in Asia/Africa/South America. 

  • Early: 
    • Maculopapular rash – lasts up to 2 weeks
    • “swimmer’s itch” 
  • Acute disease (=Katayama syndrome) – occurs 16 to 90 days after infection:
    • Fever 
    • Fatigue 
    • Myalgia 
    • Diarrhoea 
    • RUQ pain
    • Cough
  • Chronic disease (granuloma formation): 
    • Splenomegaly 
    • Hepatomegaly 
    • Gastrointestinal inflammation, possibly causing haematochezia 
    • Liver fibrosis (S. mansoni, S. japonicum) 
    • Inflammation/obstruction of urinary tract with haematuria (S. haematobium)
      • Increased risk of squamous cell carcinoma of bladder 
    • Acute transverse myelitis/subacute myeloradiculopathy (S mansoni and S haematobium)
  • Examination 
  • FBC – look for eosinophilia
  • Microscopy of urine/stools
    • Characteristic eggs – they have a lateral or terminal spine so look a little like a cartoon “speech bubble” 
    • Wait 2 months since last freshwater contact as it takes this length of time for eggs to become apparent 

Treatment: oral praziquantel 

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