Eco-epidemiology and control of Chagas disease in northern Argentina


A long-term One Health collaborative effort of the University of Buenos Aires (led by Ricardo Gürtler, PhD), Rockefeller and Columbia University (Joel E. Cohen, PhD) and Emory University (Uriel Kitron, PhD, MPH) on the ecology, epidemiology and suppression of Chagas disease in the Argentinean Chaco.


A strength of the project is that it addresses all facets of transmission and risk, including the parasite Trypanosoma cruzi (which causes Chagas disease), the insect vectors, the wildlife and domestic reservoir hosts, humans and the physical and biological environments. Among the major findings of the projects is the high degree of heterogeneity in all of these components of the transmission systems. Infestations are highly aggregated, with only a few premises harboring high-density bug colonies. Some peridomestic structures with particular physical attributes maintain residual bug colonies that can recover to pre-intervention numbers and propagate through the community by flight dispersal.


Among our main findings are the inter-connectedness between domestic, peridomestic and Sylva tic populations of the main vector Triatoma infestans (Hemiptera: Reduviidae), the importance of super-spreader dogs and high-risk sites, the occurrence of unanticipated sylvatic foci of Triatoma infestans, and the economically optimal role for community action in sustainable Chagas disease intervention programs.


A key finding of the study is the importance of dogs to the transmission of T. cruzi and to the surveillance of Chagas disease. Dogs are the key reservoir for T. cruzi and the major source of infection for Triatoma infestans, the main vector of Chagas disease in the Chaco, with a force of infection that is 14 times higher than that of humans. Dogs, whose average lifespan in the rural Chaco is only 3.5 years, also fulfill all the criteria for an optimal sentinel for Chagas disease. Trypanosoma cruzi infection is aggregated at the household level along the “80-20 rule”, with a small fraction of the seropositive dog, and to a lesser extent cat and human populations, showing high capacity to infect bugs. Field and experimental evidence shows that dogs are the preferred domestic bloodmeal source of T. infestans.


At the district-wide level, high domestic infestation was clustered in high human-density areas with higher land surface temperature and more degraded landscapes. Anthropogenic changes in the environment, including deforestation, introduction of cash crops and changes in land ownership patterns have had major impacts on wildlife, including suspected reservoir hosts such as opossums and skunks.


In addition to over forty scientific papers that resulted from the project, there is a strong training component for undergraduate and graduate students, post-docs and veterinarians, and the project is based on and committed to community participation and sustainable improvement in public health.


Links to free access key papers (all accessible through PubMed):


Ceballos 2009 -

Gurtler, PNAS -

Vazquez-Prokopec, PLOS NTD -

Gurtler, Parasitology -

Cecere, EID -

Cardinal 2009


Uriel Kitron, PhD, MPH

Department of Environmental Studies

400 Dowman Drive

Math and Science Center, Suite E511

Emory University

Atlanta, GA  30322

Tel: (404) 727-4253; fax: (404) 727-4448;                                                                                                                                                                                                                                 


Ricardo Gürtler, PhD

CONICET Scientific Investigator

Professor and Head

Laboratory of Eco-Epidemiology

Faculty of Natural and Exact Sciences

University of Buenos Aires



Dr. Kitron graciously provided this article to the One Health Initiative website. This was requested following the previous July 28, 2010 OHI website Publications page (scroll down) posting of a news item on NEWKERALA.COM.  Prepared by Drs. Kitron and Gürtler, it is expected to be re-printed in the One Health Newsletter’s Fall issue