Schistosomiasis

Schistosomiasis (bilharzia) is a parasitic infection caused by Schistosoma worms, acquired through contact with freshwater contaminated by infected snails. It is common in many parts of Tanzania where communities rely on lakes, rivers, or irrigation canals.

• Itchy rash shortly after exposure to contaminated water ("swimmer's itch") in some people
• Blood in the urine, most typical of urinary schistosomiasis
• Abdominal pain, diarrhoea, or blood in the stool with intestinal schistosomiasis
• Fatigue and, over years of untreated infection, complications affecting the bladder, kidneys, liver, or intestines

• Caused by Schistosoma worms (commonly S. haematobium for urinary disease, and S. mansoni for intestinal disease in this region).
• Acquired through skin contact with freshwater containing larvae released by infected freshwater snails, such as while swimming, bathing, washing clothes, or farming in irrigated fields.
• Risk is highest in communities with regular contact with lakes, rivers, dams, or irrigation canals where the host snails live.

• Diagnosed by finding Schistosoma eggs on microscopy of urine (for urinary schistosomiasis) or stool (for intestinal schistosomiasis).
• A history of regular freshwater contact in an endemic area supports the diagnosis.
• Ultrasound may be used to assess for bladder or kidney changes in more advanced or longstanding infection.

Praziquantel, given as a single oral dose based on body weight, is the treatment of choice for all forms of schistosomiasis.

Mass drug administration campaigns using praziquantel are conducted periodically in known endemic communities, particularly targeting school-age children.

Advanced complications, such as significant bladder or kidney damage, are referred for specialist assessment and management.

• Avoid swimming, bathing, or wading in untreated freshwater lakes, rivers, or canals in known endemic areas.
• Use safe, piped or treated water for washing and bathing where possible.
• Support community mass treatment campaigns and snail-control efforts in endemic areas.
• Seek treatment promptly if exposure and symptoms suggest infection, and support regular deworming programmes for school-age children in endemic areas.