Parasite

Schistosomiasis

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Schistosomiasis, Bilharziasis, Katayama Fever, Acute Schistosomiasis, Acute Toxemic Schistosomiasis

  • Pathophysiology
  1. Trematode Parasite
    1. Schistosoma mansoni (South America, Caribbean, Africa)
      1. Affects hepatic and intestinal tract
    2. Schistosoma japonicum (Asia)
      1. Affects hepatic and intestinal tract
    3. Schistosoma haematobium (Africa)
      1. Affects genitourinary tract
  2. Vectors
    1. Fluke
    2. Intermediary freshwater snail host
  3. Affected regions
    1. Sub-Saharan Africa
    2. Southeast Asia
  4. Parasite enters unbroken skin in infested fresh water
    1. Boating or swimming in endemic regions
    2. Illness is secondary to immunologic response to schistosomal worms
  5. Incubation Period
    1. Illness onset 4-8 weeks after exposure
  • Symptoms
  • Acute Illness (Katayama Fever)
  1. Flu-like illness symptoms
    1. Fever
    2. Fatigue
    3. Malaise
    4. Arthralgias
  2. Respiratory symptoms
    1. Nonproductive Cough
    2. Bronchospasm
  3. Gastrointestinal symptoms
    1. Abdominal Pain
    2. Diarrhea
    3. Weight loss
  4. Skin
    1. Urticaria
  • Differential Diagnosis
  • Acute Illness (Katayama Fever)
  1. See Fever in the Returning Traveler
  2. Malaria
  3. Typhoid
  • Imaging
  • Acute Illness (Katayama Fever)
  1. Chest XRay with Pulmonary Infiltrates
    1. Present 4 to 6 weeks after travel
  • Labs
  1. Complete Blood Count
    1. Eosinophilia
  • Diagnosis
  • Microscopic exam of stool and urine
  1. Eggs (uncommonly seen in light infections)
  2. Eosinophilia
    1. Differentiates Schistosomiasis from other causes of Fever in the Returning Traveler
  • Complications
  1. Chronic infection affecting liver, Bladder, Uterus, Gastrointestinal Tract
  2. Severe neurologic sequelae (rare)
    1. CNS or spinal cord lesions (Schistosoma japonicum)
  • Management
  • Acute Toxemic Schistosomiasis (Katayama Fever)
  1. Prednisone for 3-6 days
  2. Praziquantel 40-60 mg/kg for 1-3 doses on same day
    1. Consider repeating Praziquantel in 4-6 weeks after worms have matured
  • References
  1. Black, Martin, DeVos (2018) Crit Dec Emerg Med 32(8): 3-12
  2. (2018) Sanford Guide, Accessed on IOS 8/2/2018