Influence of Vectors' Risk-Spreading Strategies and Environmental Stochasticity on the Epidemiology and Evolution of Vector-Borne Diseases: The Example of Chagas' Disease

• Autores: Pelosse, Perrine; Kribs Zaleta, Cristhoper Mitchell; Giniux, Marine; Rabinovich, Jorge Eduardo; Gourbière, Sébastien; Menu, Frédéric
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: EVOLUTION; CHAGAS DISEASE; TRYPANOISOMA CRUZI; MATHEMATICAL MODELING
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Insects are known to display strategies that spread the risk of encountering unfavorable conditions, thereby decreasing the extinction probability of genetic lineages in unpredictable environments. To what extent these strategies influence the epidemiology and evolution of vector-borne diseases in stochastic environments is largely unknown. In triatomines, the vectors of the parasite Trypanosoma cruzi, the etiological agent of Chagas' disease, juvenile development time varies between individuals and such variation most likely decreases the extinction risk of vector populations in stochastic environments. We developed a simplified multi-stage vector-borne SI epidemiological model to investigate how vector risk-spreading strategies and environmental stochasticity influence the prevalence and evolution of a parasite. This model is based on available knowledge on triatomine biodemography, but its conceptual outcomes apply, to a certain extent, to other vector-borne diseases. Model comparisons between deterministic and stochastic settings led to the conclusion that environmental stochasticity, vector risk-spreading strategies (in particular an increase in the length and variability of development time) and their interaction have drastic consequences on vector population dynamics, disease prevalence, and the relative short-term evolution of parasite virulence. Our work shows that stochastic environments and associated risk-spreading strategies can increase the prevalence of vector-borne diseases and favor the invasion of more virulent parasite strains on relatively short evolutionary timescales. This study raises new questions and challenges in a context of increasingly unpredictable environmental variations as a result of global climate change and human interventions such as habitat destruction or vector control.
Fil: Pelosse, Perrine. Public Health England; Reino Unido. Centre National de la Recherche Scientifique; Francia. University of Texas; Estados Unidos. Université Claude Bernard Lyon 1; Francia
Fil: Kribs Zaleta, Cristhoper Mitchell. University of Texas; Estados Unidos
Fil: Giniux, Marine. Centre National de la Recherche Scientifique; Francia. Université Claude Bernard Lyon 1; Francia
Fil: Rabinovich, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina
Fil: Gourbière, Sébastien. Centre National de la Recherche Scientifique; Francia. Université de Perpignan Via Domitia; Francia. University of Sussex; Reino Unido
Fil: Menu, Frédéric. Université Claude Bernard Lyon 1; Francia. Centre National de la Recherche Scientifique; Francia