[Water, sanitation and diarrheal risk in Nouakchott Urban Community, Mauritania]. / Eau potable, assainissement et risque de maladies diarrhéiques dans la Communauté Urbaine de Nouakchott, Mauritanie.

INTRODUCTION: Drinking water and sanitation are two factors of inter-linked inextricably public health especially in the city of Nouakchott where the low availability of these services leads to a multitude of use and hygiene practices involving a complex socio-ecological system with an increased risk of waterborne diseases transmission (diarrhea, cholera, etc.). METHODS: Thus, this contribution analyzes the impact of socio-ecological system on the development of diarrheal diseases by using socio-environmental and epidemiological data from various sources (national surveys and registries consultation). RESULTS: Overall, the results show that only 25.6% of households have access to drinking water sources while 69.8% of the populations dispose improved latrines. Hence, the weakness in environmental sanitation conditions explains the level of diarrheal morbidity averring 12.8% at the urban level, with an unequal spatial distribution showing less affected communes such as Tevragh Zeina (9.1%) and municipalities more affected like Sebkha (19.1%). The distribution according to the age categories shows that children under 5 years are the most affected with 51.7% followed by people aged over 14 with 34.2%. The correlation analysis between socio-economic, environmental and epidemiological variables reveals a number of significant associations: untreated water consumption and diarrhea (R = 0.429); collection of wastewater and occurrence of diarrhea ; existence of improved latrine and reduction of diarrheal risk (R = 0.402). DISCUSSION: Therefore, exposure to diarrheal diseases through the prism of water and sanitation is a real public health problem that requires a systemic and integrated approach to improving environmental health.

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

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.

Absence of dry season Plasmodium parasitaemia, but high rates of reported acute respiratory infection and diarrhoea in preschool-aged children in Kaédi, southern Mauritania.

BACKGROUND: The epidemiology of malaria in the Senegal River Gorgol valley, southern Mauritania, requires particular attention in the face of ongoing and predicted environmental and climate changes. While "malaria cases" are reported in health facilities throughout the year, past and current climatic and ecological conditions do not favour transmission in the dry season (lack of rainfall and very high temperatures). Moreover, entomological investigations in neighbouring regions point to an absence of malaria transmission in mosquito vectors in the dry season. Because the clinical signs of malaria are non-specific and overlap with those of other diseases (e.g. acute respiratory infections and diarrhoea), new research is needed to better understand malaria transmission patterns in this region to improve adaptive, preventive and curative measures. METHODS: We conducted a multipurpose cross-sectional survey in the city of Kaédi in April 2011 (dry season), assessing three major disease patterns, including malaria. Plasmodium spp. parasite rates were tested among children aged 6-59 months who were recruited from a random selection of households using a rapid diagnostic test and microscopic examination of Giemsa-stained thick and thin blood films. Acute respiratory infection and diarrhoea were the two other diseases investigated, administering a parental questionnaire to determine the reported prevalence among participating children. FINDINGS: No Plasmodium infection was found in any of the 371 surveyed preschool-aged children using two different diagnostic methods. Acute respiratory infections and diarrhoea were reported in 43.4% and 35.0% of the participants, respectively. About two thirds of the children with acute respiratory infections and diarrhoea required medical follow-up by a health worker. CONCLUSIONS: Malaria was absent in the present dry season survey in the capital of the Gorgol valley of Mauritania, while acute respiratory infections and diarrhea were highly prevalent. Surveys should be repeated towards the end of rainy season, which will enhance our understanding of the potential changes in malaria transmission in a region known as 'hot spot' of predicted climate change.