Can clean water eliminate parasitic diseases?

Every day, millions of children around the world are exposed to parasitic worm infections—often just by drinking water, walking barefoot, or using unsafe toilets.

Diseases, like schistosomiasis and soil-transmitted helminthiases, can stunt growth, damage organs, and keep children out of school. 

Improving access to clean water, safe toilets, and hygiene education dramatically reduces the risk of infection. Studies show that water, sanitation and hygiene (WASH) interventions can cut parasitic worm infections by up to 70%.  

In fact, countries like Japan and South Korea have eliminated these diseases largely through environmental improvements. 

But in high-burden areas—where infrastructure is weak and reinfection is common—WASH alone isn’t enough. 

Deworming is still essential 

Even with better sanitation, children can still be exposed to parasites in contaminated soil or water. That’s why mass drug administration (MDA) remains essential is critical to break the cycle of disease. Regular treatment helps break the cycle of infection while WASH systems are built and scaled. Together, WASH and MDA form a powerful combination: WASH prevents new infections and MDA clears existing ones. 

The World Health Organization recommends an integrated approach that includes preventive treatment, clean water access, sanitation infrastructure and hygiene education 

This is how we move from control to elimination—and eventually, to a world free from parasitic disease. 

“Challenges caused by climate change, social instability and conflict, together with increasing financial pressures globally, are threatening to undermine efforts to reduce and eliminate parasitic infections. Now, more than ever, is the time to collaborate with, and invest in, better and more equitable water supply and sanitation services.”

Yael Velleman

Director of Policy & Innovation

Tune into this BBC World Service programme where our Head of Policy and Innovation Yael Velleman explores the global impact of inadequate access to clean water and sanitation—and what it means for vulnerable communities around the world. 

You can help end parasitic diseases 

Support programs that combine treatment with long-term WASH solutions. Help communities build toilets, access clean water, and learn safe hygiene practices. And fund the medicines that protect children while those systems grow. 

Because no child should suffer from a disease we already know how to prevent. 

Clean water helps—but it’s not enough alone 

WASH is vital, but without treatment, parasitic diseases will persist. Together, we can build a future where no child suffers from preventable infections. 

Find out more about our Community led-WASH project in Uganda