03089nas a2200277   4500000000100000008004100001653001800042653002000060653001600080653000800096653003000104100001100134700001400145700001100159700001600170700001100186700001400197700001500211700001100226245011200237856007900349300001300428490000600441520235000447022001402797       2015                            d10aTransmissions10aResearch models10aMethodology10aHSI10aHabitat suitability index1 aWalz Y1 aWegmann M1 aDech S1 aVounatsou P1 aPoda J1 aN'Goran E1 aUtzinger J1 aRaso G00aModeling and validation of environmental suitability for schistosomiasis transmission using remote sensing.  uhttp://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004217   ae00042170 v93 a<p><strong>BACKGROUND: </strong>Schistosomiasis is the most widespread water-based disease in sub-Saharan Africa. Transmission is governed by the spatial distribution of specific freshwater snails that act as intermediate hosts and human water contact patterns. Remote sensing data have been utilized for spatially explicit risk profiling of schistosomiasis. We investigated the potential of remote sensing to characterize habitat conditions of parasite and intermediate host snails and discuss the relevance for public health.</p>

<p><strong>METHODOLOGY: </strong>We employed high-resolution remote sensing data, environmental field measurements, and ecological data to model environmental suitability for schistosomiasis-related parasite and snail species. The model was developed for Burkina Faso using a habitat suitability index (HSI). The plausibility of remote sensing habitat variables was validated using field measurements. The established model was transferred to different ecological settings in Côte d'Ivoire and validated against readily available survey data from school-aged children.</p>

<p><strong>PRINCIPAL FINDINGS: </strong>Environmental suitability for schistosomiasis transmission was spatially delineated and quantified by seven habitat variables derived from remote sensing data. The strengths and weaknesses highlighted by the plausibility analysis showed that temporal dynamic water and vegetation measures were particularly useful to model parasite and snail habitat suitability, whereas the measurement of water surface temperature and topographic variables did not perform appropriately. The transferability of the model showed significant relations between the HSI and infection prevalence in study sites of Côte d'Ivoire.</p>

<p><strong>CONCLUSIONS/SIGNIFICANCE: </strong>A predictive map of environmental suitability for schistosomiasis transmission can support measures to gain and sustain control. This is particularly relevant as emphasis is shifting from morbidity control to interrupting transmission. Further validation of our mechanistic model needs to be complemented by field data of parasite- and snail-related fitness. Our model provides a useful tool to monitor the development of new hotspots of potential schistosomiasis transmission based on regularly updated remote sensing data.</p>
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