The problem: intestinal worms and parasites
Schistosomiasis (shis-toe-so-my-a-sis) and soil-transmitted helminthiasis (STH) are both what the World Health Organization calls “neglected tropical diseases,” which affect the poorest and most marginalized communities in the world. Schistosomiasis is carried by freshwater snails and transmitted through contaminated water during everyday activities, such as bathing, fishing, and washing clothes in lakes, rivers, or ponds. STH is caused by a group of intestinal parasites, and is transmitted through soil contaminated with human feces.
The World Health Organization estimates that 206 million people are affected by schistosomiasis and 1.5 billion are infected with STH  . Infection with these parasites can result in anemia, blood in urine, abdominal pain, and genital discomfort. These symptoms can lead to impaired cognitive development and reduced school attendance; longer-term effects include stunted growth, internal organ damage (such as liver fibrosis), increased risk of HIV infection, and bladder cancer.
The solution: cost-effective school deworming programs
Mass deworming programs — typically run by national governments — provide those living in at-risk communities the medication needed to treat STH and schistosomiasis infections. These programs have a strong track record of success and are highly cost-effective, generally at around 43 cents per child per year. The estimated long-run social financial rate of return is around 65% per year. 
—Innovations for Poverty Action 
How the Schistosomiasis Control Initiative works
SCI does not have country offices or local staff. Rather, they work directly with government programs to help deliver services through existing health care systems. By providing technical support, SCI can remain agile and responsive, and focus on building capacity and maximizing efficiency. Plus, working in partnership increases their organizational cost effectiveness, while reducing duplicative efforts.