Schistosomiasis

Question 1

Cause

Answer 1

Parasites Schistosoma
S.mansoni
S.japonicum
S.haematobium

Question 2

Signs and sx

Answer 2

From body’s immune response to parasite eggs
Eggs lodge in intestines, liver, urogenital

Rash + itch on skin within days of infection
Within 1-12 weeks - Fevers, chills, cough (other respiratory sx), myalgia, headache

Cough can persist for 6 wks

Chronic infection: can persists for years
Hepato +/- splenomegaly - liver fibrosis, portal HTN
Abdominal pain
Haematuria
Blood in stools
Difficulty urinating

Risk of bladder Ca

Rare, but if eggs in brain or spinal cord - paralysis, seizures, spinal cord inflammation

Question 3

Investigations

Answer 3

Eosinophilia (not always, and >3 wks after exposure)
Serology for anti-schistosomal antibody (Can take 3-6 months to be positive)- however cannot distinguish between active and resolved infection
Stool and urine OCP - may have few eggs, low sensitivity
3 separate specimens (may take >50 days to be present)

Question 4

Treatment

Answer 4

DO NOT treat ACUTE schistosomiasis with Praziquantel - can cause worsening of sx, potentially life-threatening!!
Refer to ID, may need corticosteroids
Treat >6-8 wks after exposure to contaminated water
Praziquantel - for 1-2 days

S. mansoni, S. haematobium, S. intercalatum :
40 mg/kg per day orally in two divided doses for one day
S. japonicum, S. mekongi:
60 mg/kg per day orally in three divided doses for one day