Provision of sustainable sanitation in emergency situations: role of ecosan

This paper describes the potential of ecological sanitation (ecosan), and in particular of urine-diversion dehydrating (UDD) toilets, to provide sustainable excreta disposal in emergency situations in low-income countries. Three case studies of emergency sanitation were analysed: El Salvador (hurricane), Afghanistan (civil war) and Pakistan (earthquake). The analysis of these case studies has shown that the systems implemented in the long-term phase of the emergency were sometimes more sustainable than what was in place before the emergency occurred. For UDD toilets to be viable during emergency situations, specific criteria have to be in place. The essential criteria include awareness and expertise among aid agencies, ease of transportation and quick installation of standardised UDD units, stage and duration of emergency and the role of government in sanitation provision. For emergency situations in low-income countries, we propose the use of UDD toilets (e.g. with pre-fabricated urine-diversion squatting pans) as a suitable excreta management option, particularly in those instances where pit latrines are not sustainable in the longer term

Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009

BACKGROUND: In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. METHODS: We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. RESULTS: This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. CONCLUSION: This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic