ABSTRACT
Infectious diarrhoea is probably the largest contributor to the disease burden from water, sanitation and hygiene – although it is also transmitted through food and air. Disease burdens from diarrhoeal diseases in children younger than five can be up to 240 times higher in low-income nations than high-income nations. And if data were available for how diarrhoeal disease burdens varied between different income groups (or between those living in informal settlements and those in good quality housing), the differentials could be even larger. For instance, the prevalence of diarrhoea among children under three in many of Nairobi’s informal settlements was found to be twice the national average (and the rural average) while the prevalence of diarrhoea with blood (which signifies serious systemic infection) was often three to four times the national average (and rural average).18
