Ecological connectivity of Trypanosoma cruzi reservoirs and Triatoma pallidipennis hosts in an anthropogenic landscape with endemic Chagas disease

PLoS One. 2012;7(9):e46013. doi: 10.1371/journal.pone.0046013. Epub 2012 Sep 26.

Abstract

Traditional methods for Chagas disease prevention are targeted at domestic vector reduction, as well as control of transfusion and maternal-fetal transmission. Population connectivity of Trypanosoma cruzi-infected vectors and hosts, among sylvatic, ecotone and domestic habitats could jeopardize targeted efforts to reduce human exposure. This connectivity was evaluated in a Mexican community with reports of high vector infestation, human infection, and Chagas disease, surrounded by agricultural and natural areas. We surveyed bats, rodents, and triatomines in dry and rainy seasons in three adjacent habitats (domestic, ecotone, sylvatic), and measured T. cruzi prevalence, and host feeding sources of triatomines. Of 12 bat and 7 rodent species, no bat tested positive for T. cruzi, but all rodent species tested positive in at least one season or habitat. Highest T. cruzi infection prevalence was found in the rodents, Baiomys musculus and Neotoma mexicana. In general, parasite prevalence was not related to habitat or season, although the sylvatic habitat had higher infection prevalence than by chance, during the dry season. Wild and domestic mammals were identified as bloodmeals of T. pallidipennis, with 9% of individuals having mixed human (4.8% single human) and other mammal species in bloodmeals, especially in the dry season; these vectors tested >50% positive for T. cruzi. Overall, ecological connectivity is broad across this matrix, based on high rodent community similarity, vector and T. cruzi presence. Cost-effective T. cruzi, vector control strategies and Chagas disease transmission prevention will need to consider continuous potential for parasite movement over the entire landscape. This study provides clear evidence that these strategies will need to include reservoir/host species in at least ecotones, in addition to domestic habitats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chagas Disease / epidemiology
  • Chagas Disease / parasitology
  • Chagas Disease / transmission
  • Chiroptera
  • Ecology
  • Ecosystem
  • Endemic Diseases
  • Geography
  • Humans
  • Insect Vectors / parasitology
  • Mexico
  • Models, Statistical
  • Prevalence
  • Risk Factors
  • Rodentia
  • Triatoma / parasitology*
  • Trypanosoma cruzi / parasitology*

Grants and funding

This study was funded by the Secretaria de Salud and Consejo Nacional de Ciencia y Tecnología (CONACyt) project MOR-2004-CO2-012 to JMR, and by the Universidad Nacional Autónoma de México (PAPIIT project 225408 to VS-C, and the Sistema de Informática para la Biodiversidad y el Ambiente [SIBA], and Tecnologías para la Universidad de la Información y la Computación. AEGC was funded with a scholarship from CONACyT for a M. Sc. degree in vector-borne diseases at the Instituto Nacional de Salud Publica. CNIC is funded with a scholarship from CONACyT for studies at the graduate program in Biomedical Sciences of the Universidad Nacional Autonoma de Mexico. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.