Ecological Niche Modeling as a Tool for Understanding Distributions and Interactions of Vectors, Hosts, and Etiologic Agents of Chagas Disease

Abstract

Chagas disease, or American Trypanosomiasis, is a tropical parasitic disease caused by the flagellate protozoan Trypanosoma cruzi, which is in turn transmitted by blood-sucking insects of the subfamily Triatominae (family Reduviidae). Because no drugs or vaccines are available to cure Chagas disease in its chronic phase, vectorial control (i.e., insecticide spraying) constitutes the principal means by which to impair Chagas disease transmission. Environmental and social factors have caused changes in the epidemiology of this disease-it was originally restricted to Latin America, but is now becoming a global heath concern in non-endemic areas as a consequence of human migrations. In Brazil, despite the fact that the most effective vector has been controlled, other triatomine species infest and colonize domiciliary habitats and can transmit the pathogen. As a consequence, Chagas disease transmission continues: the prevalence of the disease remains at ∼12 million people, with ∼200,000 new cases per year in 15 countries of Latin America, making control actions still necessary. Understanding the environmental requirements and geographic distributions of vectors is key to guiding control measures, and understanding better epidemiologic aspects of the disease. Ecologic niche modeling is a relatively new tool that permits such insights--as a consequence, here, we present an overview of insights gained using this approach in understanding of Chagas disease.