What is schistosomiasis?

Schistosomiasis (also known as snail fever or bilharzia) is an illness that develops when people come into contact with water contaminated by certain snails carrying the disease-causing parasites, which penetrate the skin and move through the body.

Infection primarily affects the urinary or intestinal system, causing chronic ill health and in some cases death. Poor hygiene and water-based activities (such as swimming and fishing) make school-age children the most vulnerable, with infection responsible for malnutrition, absenteeism, and impaired intellectual development.

Children suffering from persistent and severe schistosomiasis infections are also likely to have chronic irreversible diseases later in life, such as scarring (fibrosis) of the liver, bladder cancer, or kidney failure.


People affected by schistosomiasis

218.2 million people required treatment in 2015 92% of people requiring preventive chemotherapy live in Africa 78 countries are endemic for schistosomiasis

WHO NTD roadmap targets for schistosomiasis

The World Health Organization’s roadmap on NTDs set out a comprehensive plan for the control, elimination and eradication of various neglected tropical diseases by 2020, including schistosomiasis.

Schistosomiasis target: Control by 2020

  • Control morbidity and achieve treatment coverage of at least 75% of all school-age children by 2020
  • Regional elimination in the Eastern Mediterranean Region, the Caribbean, Indonesia and the Mekong River Basin by 2015
  • Regional elimination in the Americas Region, Western Pacific Region and in selected countries in the African Region by 2020

Progress and scorecard from the 5th progress report

Since 2012, we have monitored progress annually for each disease. This information is from the 5th progress report of the London Declaration published in 2017.

Coverage and impact
Programme support
Drug requests filled
Overall progress

Mass drug administration status for school-age children for schistosomiasis

People receiving preventive chemotherapy for schistosomiasis

Since the London Declaration was signed in 2012 and partners committed to defeating neglected tropical diseases, the number of people receiving preventive chemotherapy for schistosomiasis has increased considerably.


  • Data is provided by the World Health Organization
  • Photo: © GSK / Marcus Perkins