Water quality and health in a Sahelian semi-arid urban context: an integrated geographical approach in Nouakchott, Mauritania

Abstract

Abstract. Access to sufficient quantities of safe drinking water is a human right. Moreover, access to clean water is of public health relevance, particularly in semi-arid and Sahelian cities due to the risks of water contamination and transmission of water-borne diseases. We conducted a study in Nouakchott, the capital of Mauritania, to deepen the understanding of diarrhoeal incidence in space and time. We used an integrated geographical approach, combining socio-environmental, microbiological and epidemiological data from various sources, including spatially explicit surveys, laboratory analysis of water samples and reported diarrhoeal episodes. A geospatial technique was applied to determine the environmental and microbiological risk factors that govern diarrhoeal transmission. Statistical and cartographic analyses revealed concentration of unimproved sources of drinking water in the most densely populated areas of the city, coupled with a daily water allocation below the recommended standard of 20 l per person. Bacteriological analysis indicated that 93% of the non-piped water sources supplied at water points were contaminated with 10-80 coliform bacteria per 100 ml. Diarrhoea was the second most important disease reported at health centres, accounting for 12.8% of health care service consultations on average. Diarrhoeal episodes were concentrated in municipalities with the largest number of contaminated water sources. Environmental factors (e.g. lack of improved water sources) and bacteriological aspects (e.g. water contamination with coliform bacteria) are the main drivers explaining the spatio-temporal distribution of diarrhoea. We conclude that integrating environmental, microbiological and epidemiological variables with statistical regression models facilitates risk profiling of diarrhoeal diseases. Modes of water supply and water contamination were the main drivers of diarrhoea in this semi-arid urban context of Nouakchott, and hence require a strategy to improve water quality at the various levels of the supply chain.

The nexus between improved water supply and water-borne diseases in urban areas in Africa: a scoping review

“…However, the publications reported piped water insufficiency through proportion of the study population that had access to piped water (n=23, 72%), scheduled/ unpredictable water interruptions (n=8, 25%), per capita daily water availability (n=5, 16%) and time used/ distance to the water point (n=3, 9%). Four articles reported piped water inequality through the mode of access (n=3, 9%) 42,50,52 , quantity (n=2, 6%) 38,52 , cost (n=1, 3%) 52 and the scheduled water interruptions (n=1, 3%) 38 .…”

“…To complement their water needs, the study population employed coping mechanisms which included collecting rainwater/ water from rivers, streams or shallow wells (n=22, 69%), purchasing water either from vendors (n=16, 50%) or neighbors (n=1, 3%), storing water in the households (n=11, 34%), water treatment (n=8, 25%), drilling wells/ boreholes (n=3, 9%), installing storage tanks in households (n=1, 3%) and having illegal water connections (n=1, 3%) (Table 4). Four of the studies reported a relatively higher cost in the purchased water as compared to the cost of water supplied by the utility companies 35,41,52,53 .…”

Water, Sanitation and Diarrhoeal Diseases in Nouakchott (Mauritania): Analysing the Determinant of Urban Health Inequalities

“…Within an international research program, NCCR-North South (National Centre of Competence in Research North-South), we build a multidisciplinary research group addressing the issues of environmental sanitation, health and well-being in disadvantaged urban areas. This approach of research group is founded in the concepts of vulnerability and resilience to health risks to develop a systems-thinking through close collaboration between different disciplines, such as medicine, epidemiology, public health, ecology, geography, climatology, anthropology, sociology, economics and political science for better health and well-being improvement of vulnerable communities [17,18]. Following the conceptualization of vulnerability and resilience, results presented in this paper is the contributive output from the multidisciplinary research group to make a first statement step for more comprehensive finding of health and environmental sanitation interlinkages in Nouakchott urban areas.…”

Access to, and use of, water by populations living in a schistosomiasis and fascioliasis co-endemic area of northern Côte d’Ivoire

“…Water is an indispensable source of life, yet it can also be a source of disease (Fenwick, 2006;Steinmann et al, 2006;Traoré et al, 2013). A plethora of bacteria, parasites, protozoa and viruses are transmitted via water.…”