Document Type

Article

Source Publication Title

PLoS ONE

DOI

http://dx.doi.org/10.1371/journal.pone.0070830

Abstract

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 riskspreading 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.

Disciplines

Mathematics | Physical Sciences and Mathematics

Publication Date

1-1-2013

Language

English

Comments

This work has been supported by the French National Research Agency (grant reference ‘‘ANR-08-MIE-007’’), by the National Science Foundation (grant reference ‘‘DMS-1020880’’), and by the Agencia Nacional de Promocio´n Cientı´fica y Tecnolo´ gica of Argentina (grant reference PICT2008-0035). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Included in

Mathematics Commons

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