Tap water access and its relationship with cholera and other diarrhoeal diseases in an urban, cholera-endemic setting in the Democratic Republic of the Congo

Abstract

Globally 1.3 billion people are at risk of cholera in endemic countries, where nearly 3 million cases occur annually, of which 3 % are fatal. The burden is highest in South-Asia and Sub-Saharan Africa, where diarrhoeal diseases in general are also a leading cause of mortality and morbidity, especially for children under 5. Uvira, the second largest city of South-Kivu province in the eastern part of the Democratic Re-public of the Congo, has been affected by cholera since it reached the region in the late 1970s. Suspected cholera cases have been reported nearly every week since 2004 by the Uvira cholera treatment centre (CTC). This thesis first shows that about 40% of the patients admitted to the CTC test positive for cholera with rapid diagnostic tests, and that infections with other common enteric pathogens are highly prevalent. Two surveys of water-related practices in more than 500 households indicate that tap water is sometimes used by nearly 80% of households for drinking purposes but only systematically by less than 50%, whilst surface water is the main source of domestic water for nearly 40% of households. Tap water access is a predictor of the quality and quantity of domestic water used in households. Time-series regression reveals a 2.5-fold increase in CTC admissions within the 12 days following a 24h interruption in tap water supply. Finally, a multivariable time-series model high-lights the influence of tap water supply variability in time and space on suspected chol-era incidence, especially that attributed to epidemic transmission. By demonstrating the influence of coverage disparities and intermittency of the current tap water supply network on households’ water-related practices and suspected cholera incidence in Uvira, this research establishes a solid base for a much-needed impact evaluation of on-going improvements on suspected cholera in an endemic area.