In 131 house-to-house surveys conducted in 41 African countries during 1991 and 2002, it has become clear that the population’s access to drinking water and sanitation is highly varied. The coverage of drinking water is as low as 3.2 per cent in some districts of Somalia and as high as 99 per cent in urban Namibia. The figure for sanitation access ranges from 0.2 per cent in Chad to 100 per cent in Gambia. The distribution mapÔÇêcan be used to highlight deprived areas and groups, previouslyÔÇêhidden in national statistics, for relevant policy interventions. PloS Medicine, April 8