Many countries, particularly in sub-Saharan Africa, are unlikely to reach Millennium Development Goal (MDG) 4 (a two-thirds reduction in under-5 mortality between 1990 and 2015). Diarrhoea caused 15% of under-5 deaths (1.3 million deaths) in 2008 and poor water supply and sanitation are the main underlying problem. MDG7 calls for a halving of the number of people without access to safe drinking water …