Hygiene, Sanitation, and Water: Forgotten Foundations of Health

Every year, around 2.4 million deaths worldwide (4.2% of all deaths) could be prevented if everyone practised appropriate hygiene and had good, reliable sanitation and drinking water. The majority of these deaths are children in developing countries dying from diarrhoea and subsequent malnutrition, and from other diseases attributable to malnutrition.
How is an opportunity to prevent so many deaths (and 6.6% of the global burden of disease in terms of disability-adjusted life years or DALYs failing to attract the attention of the international public health community?