Handwashing with soap is the single most cost-effective intervention and it reduces disability-adjusted life years (DALYs) related to diarrheal diseases by a significant margin.
Research shows that every $3.35 invested in handwashing programs prevents one disability-adjusted life year (DALYs). In comparison, gaining that same year by promoting latrines would cost $11, and promoting household water connection would cost more than $200. Failing to invest in handwashing promotion therefore means missing very inexpensive life-saving opportunities.
Research suggests that soap is available in most households in the world, including poor households in developing countries although it is primarily used for bathing and washing clothes.
Handwashing with soap can mean more school days for children.
Diarrhea is responsible for children missing hundreds of millions of school days every year. By having children integrate the habit of handwashing with soap in their daily routines, school absenteeism could be reduced substantially. A recent study suggests that handwashing with soap at critical times could help reduce school absenteeism by around 42 percent. (Bowen et al, 2007)
For this to happen, children must have access to soap in schools. Unfortunately, this is not always the case. UNICEF and IRC conducted research in 2006 by in six developing countries that showed low rates of soap availability in schools. The report concluded, “ensuring students’ access to soap is urgently needed.”