Global environmental changes — the manifestations of which can include loss biodiversity and land used changes, increasing atmospheric temperature and climatic instability (e.g., longer and more severe periods of drought or rainfall) — are expected to affect the distribution and prevalence of various infectious diseases by making conditions more (or less) propitious for the survival of pathogens and their vectors and intermediate hosts, and by inducing mass movement of human and animal populations. In this project we intend to investigate the combined effect of climate change and land use change, in particular the development of water management infrastructures, on the distribution of snail-borne schistosomiasis, a debilitating parasitic disease of poverty, affecting more than 200 million people worldwide. We will focus on Ivory Coast and in Brazil, two countries particularly vulnerable to this parasitic disease as a consequence of projected climate change combined with growing human population, deforestation, expansion of agriculture and of marginal urban settings and the development of dams and irrigation canals. The project has three objectives: FIRST, we will use a hybrid approach integrating species distribution models accounting for the most relevant socio-economic and environmental drivers of schistosomiasis with temperature-driven, process-based mathematical models of the parasite and its intermediate snail hosts to produce maps of present and future risk for schistosomiasis under climate change. SECOND, we intend to conduct initial feasibility and nutritional studies and market analyses of aquaculture of freshwater prawns native of Brazil and of Cote d'Ivoire with the goal of using them as novel biological control agents of schistosome's snail host while, at the same time, promoting the development of small-scale aquaculture businesses. THIRD, to track future changes in the distribution and abundance of the snail hosts, we will develop machine learning algorithms that enable computer vision as an "environmental diagnosis" tool for the quick and accurate identification of potential schistosome-host snails and parasites from field-acquired cellphone images, trained on thousands of images that have been identified to species by the gold standard of DNA barcoding and PCR-RFLP.
We anticipate the following main intellectual contributions. First, the proposed research will provide a major step forward in the development of novel mixed-models for profiling schistosomiasis risk by integrating mechanistic model of schistosomiasis transmission that include thermal sensitive parameters with remote sensing and GIS spatial representation of other ecological, environmental and socioeconomic drivers of schistosomaisis risk. Second, by combining field data at different scales with theory to investigate the linked human and natural drivers of parasite transmission, this project will improve our scientific understanding of the expected future distribution of schistosomiasis risk in Brazil and Cote d’Ivoire, two countries potentially vulnerable to future climate change and characterized by high population growth and extensive land use changes. Third, this project will provide preliminary insights on the potential use of native freshwater predators of the snails that amplify the disease as (i) biological control agent of schistosomiasis in Cote d’Ivoire and Brazil and (ii) as production animals in small scale aquaculture business. Finally, this project is transformative as it will provide a reference framework to investigate the environmental determinants of a wide family of snail-borne and soil-transmitted helminthiasis, such as fascioliasis, paragonimiasis and other helminth infections affecting over 1.5 billion of the world’s poorest people.
First, by understanding climatic, environmental and anthropogenic drivers of present and futur edistribution of schistosomiasis, this project has the potential to benefit millions of people infected or continuously exposed to Schistosoma parasites in the environment. In addition, we intend to develop a user-friendly, freely available software tool to evaluate the future risk of schistosomiasis associated with proposed development of water management infrastructure. Finally, with this project we intend to train postdoctoral students, graduate students, and undergraduates in four countries and three continents, i.e., UK, USA, Brazil and Cote d’Ivoire, as well as to develop activities to promote k-12 education and increase awareness of schistosomiasis