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

Epidémiologie moléculaire de l’infection par les virus de l'hépatite B (VHB) et de l'hépatite Delta (VHD) en Mauritanie

Date du colloque&nbsp;: 10/2009</p

Virological and epidemiological features of hepatitis delta infection among blood donors in Nouakchott, Mauritania

International audienceBackgroundIn Mauritania, some authors have described a possible high prevalence of hepatitis delta virus (HDV) infection in the 1990s in studies of small-size samples. Objectives The aims of our study were to assess the prevalence of HDV in HBsAg positive blood donors in Mauritania, to identify the main risk factors for HDV transmission and to analyze genetic diversity of HDV strains. Study design From October 2008 to December 2009, 11,100 consecutive blood donors were considered in this study. Among them, 1700 (15.3%) were HBsAg positive and 455 accepted to participate in this study. Demographic, epidemiological, ethnical, clinical and biological data were recorded. HDV screening, i.e., antibodies (HDVAb) and RNA (HDV-RNA) detection, was performed for all of them as well as HDV and HBV genotyping. Results Ninety/455 (19.78%) donors were HDVAb positive and HDV-RNA was detectable in 56 (62.2%) of them. HDV infection was significantly associated with older age, number of marriages, military profession, residence in the desert and a history of hospitalization. The HDV genotypes of the circulating strains were HDV-1 (89.3%) and HDV-5 (10.7%). Conclusion HDV is highly endemic in Mauritanian blood donors indicating that a high number of them will develop chronic hepatitis, cirrhosis or hepatocellular carcinoma. Associated risk factors support nosocomial transmission of HDV. These data underline the need to reinforce HBV vaccination in newborns and in blood donors without HBV markers, together with screening for HDV in HBV-infected individuals.</p

Environnement et santé : où en est la géographie ?

L’actualité nous rappelle l’importance du lien entre santé et environnement. L’épidémie d’ébola, qui s’est déclenchée en Afrique de l’ouest en 2013-14, est un exemple déterminant de ce lien entre environnement et santé. La géographie, discipline où l’interaction entre l’homme et le milieu naturel offre un angle de réflexion inédit sur cette question, permet de découvrir une vision globalisée des maladies et de l’accès aux soins au niveau d’une population et donc d’un territoire, du local à l’international, de l’infection à la pandémie. Les auteurs s’interrogent donc, dans cette ouvrage tout en couleur (richement illustré de photos et de cartes), sur le rôle de la géographie dans la compréhension de l’évolution des maladies, bactéries, virus, de leurs expansions. Ils essaient d’expliquer comment mettre en place des solutions sanitaires acceptables par les populations. Dans ce livre sont traités la crise ébola 2013-2014, les trypanosomiases ou maladies du sommeil, les diarrhées infectieuses, le paludisme… mais aussi les inégalités de soin, la vulnérabilité des populations face aux risques de santé en France, en Europe et dans les pays de la ceinture tropicale