Vector migration and dispersal rates for sylvatic Trypanosoma cruzi transmission

• Published in: Ecological complexity 2013-06, Vol.14, p.145-156
• Main Authors: Crawford, Britnee A., Kribs-Zaleta, Christopher M.
• Format: Article
• Language: English
• Subjects: Dispersal; Distribution; hosts; Migration; parasites; Triatoma sanguisuga; Trypanosoma cruzi; vector-borne diseases
• ISSN: 1476-945X
• DOI: 10.1016/j.ecocom.2012.11.003

► We develop a method for calculating migration rates in metapopulation models. ► We describe dispersal in terms of distance, preferred direction of dispersal, and strength of preference for ► a particular direction. ► We convert local, continuous spatial dispersal information to discrete, global migration rates. ► We apply the method to estimate migration rates for vectors of Trypanosoma cruzi. The spread of vector-borne diseases are greatly increased by a vector's ability to migrate. Recent studies of sylvatic Trypanosoma cruzi transmission have motivated the study of vector migration across geographic regions. Due to the natural mechanisms in which vector-borne diseases are transmitted between vectors and hosts, vector dispersal among different host populations is a critical factor in the ability of the parasite to be spread across large regions. In this study we develop a general framework for deriving large-scale, discrete-space migration rates from small-scale, continuous-space dispersal data. We identify three defining characteristics of vector migration: distance, preferred direction of dispersal, and strength of preference for a particular direction. We consider several migration scenarios in which vectors may have no preference for dispersal in a particular direction or may disperse with a preferred direction, such as northeast. We examine what effect preferred direction has on the migration rate, as well as use the local to global framework to calculate numerical estimates for vector migration rates for the primary vectors in the southeast U.S. and northern Mexico, Triatoma sanguisuga and Triatoma gerstaeckeri, based on biological and experimental data. Results from this study can be applied to metapopulation models for species that migrate.