Neglected Tropical Diseases affect approximately 2.7 billion people worldwide and are widely distributed, especially among the tropics. The dispersal and distribution of the pathogens that cause NTDs are strongly influenced by the spatial complexity of their physical and biotic environment. Thus, spatial analyses of abiotic and biotic variables can serve to accurately predict the emergence, occurrence, and spread of disease. Furthermore, vital to effective disease control is an understanding of the extent to which populations of parasites and their vectors are connected. In this project we propose to focus on Chagas disease in an area of disease transmission in Southern Ecuador and Northern Peru. Chagas disease is caused by the single-celled kinetoplastid Trypanosoma cruzi, and in our study region the local insect vector species is Rhodnius ecuadoriensis.
Our aim i s to establish the population genetic/genomic diversity of both vector and parasite across the study region by high resolution (genome scale) genotyping. To evaluate the interconnectivity of different vector and parasite populations, and to predict potential dispersal routes or barriers to gene-flow, we propose to adopt a landscape genetics approach. 'Landscape genetics'encompasses a body of theory and statistical tools to provide deeper insights into the interactions between landscape features (e.g. elevation, land use, population density) and spatial genetic patterns within and between populations and/or individuals.
Our aim i s to define what environmental factors and what spatial scales are relevant in defining parasite and vector population distribution. Such descriptions of diversity are key to measuring and predicting dispersal. Our evaluation of barriers to gene flow will feed directly into a rationale for effective local disease control. Furthermore our project will provide a model with which to approach the study of the dispersal and distribution of other NTD agents.
The spatial variation of the natural environment (rainfall, population density, temperature, etc.) frequently predicts the occurrence and severity of infectious disease transmission. We propose to study how spatial diversity affects the distribution and dispersal of Chagas disease parasites and insect vectors in southern Ecuador and northern Peru. To achieve this objective, we propose to combine high resolution genetic analysis of parasites and vectors with sophisticated spatial statistics to help predict disease occurrence, inform local control efforts, and provide a model for the study of other Neglected Tropical Diseases.