Dispersal patterns of Trypanosoma cruzi in Arequipa, Peru.

Alexander S F Berry,Melina Vargas-Maquera,Renzo Salazar-Sánchez,Ricardo Castillo-Neyra,Claudia Chipana-Ramos,Claudia Arevalo-Nieto,Jenny Ancca-Juarez,Katty Borrini-Mayorí,Michael Z Levy,César Náquira-Velarde,Dustin Brisson,Carlos A Buscaglia

doi:10.1371/journal.pntd.0007910

Abstract

Anthropogenic environmental alterations such as urbanization can threaten native populations as well as create novel environments that allow human pests and pathogens to thrive. As the number and size of urban environments increase globally, it is more important than ever to understand the dispersal dynamics of hosts, vectors and pathogens of zoonotic disease systems. For example, a protozoan parasite and the causative agent of Chagas disease in humans, Trypanosoma cruzi, recently colonized and spread through the city of Arequipa, Peru. We used population genomic and phylogenomic tools to analyze whole genomes of 123 T. cruzi isolates derived from vectors and non-human mammals throughout Arequipa to determine patterns of T. cruzi dispersal. The data show significant population genetic structure within city blocks-parasites in the same block tend to be very closely related-but no population structure among blocks within districts-parasites in neighboring blocks are no more closely related to one another than to parasites in distant districts. These data suggest that T. cruzi dispersal within a block occurs regularly and that occasional long-range dispersal events allow the establishment of new T. cruzi populations in distant blocks. Movement of domestic animals may be the primary mechanism of inter-block and inter-district T. cruzi dispersal.

Highlights

Human populations are increasingly moving from rural to urban centers resulting in fundamental habitat alterations that have caused local extinctions of many native species
As the number and size of urban environments increases globally, it is becoming vital to understand how human disease-causing pathogens, their vectors, and their non-human hosts disperse through urban landscapes
We study a population of Trypanosoma cruzi–the protozoan parasite and causative agent of Chagas disease in humans–that

Summary

Introduction

Human populations are increasingly moving from rural to urban centers resulting in fundamental habitat alterations that have caused local extinctions of many native species. This influx of humans and domestic animals creates suitable habitats that can be colonized by invasive species, including human pests and pathogens. Investigations into the dynamic processes of immigration, establishment, and dispersal of disease-causing agents in human-altered ecosystems are important for public health risk management because the distribution and abundance of these pest species is correlated with the incidence of disease in humans [2]. We examine the dispersal pattern of Trypanosoma cruzi, the causative agent of Chagas disease, around the region of Arequipa, Peru

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Conclusion