Eco-bio-social research on community-based approaches for Chagas disease vector control in Latin America.

Ricardo E Gürtler,Zaida E Yadon

doi:10.1093/trstmh/tru203

Abstract

This article provides an overview of three research projects which designed and implemented innovative interventions for Chagas disease vector control in Bolivia, Guatemala and Mexico. The research initiative was based on sound principles of community-based ecosystem management (ecohealth), integrated vector management, and interdisciplinary analysis. The initial situational analysis achieved a better understanding of ecological, biological and social determinants of domestic infestation. The key factors identified included: housing quality; type of peridomestic habitats; presence and abundance of domestic dogs, chickens and synanthropic rodents; proximity to public lights; location in the periphery of the village. In Bolivia, plastering of mud walls with appropriate local materials and regular cleaning of beds and of clothes next to the walls, substantially decreased domestic infestation and abundance of the insect vector Triatoma infestans. The Guatemalan project revealed close links between house infestation by rodents and Triatoma dimidiata, and vector infection with Trypanosoma cruzi. A novel community-operated rodent control program significantly reduced rodent infestation and bug infection. In Mexico, large-scale implementation of window screens translated into promising reductions in domestic infestation. A multi-pronged approach including community mobilisation and empowerment, intersectoral cooperation and adhesion to integrated vector management principles may be the key to sustainable vector and disease control in the affected regions.

Highlights

The disease is caused by the protozoan Trypanosoma cruzi which infects at least 150 mammalian species and is mainly transmitted by blood-sucking triatomine bugs.[3]
These vector species are the most successful in terms of abundance and parasite transmission, and are the main targets of vector control programs: Triatoma infestans in the southern cone countries; Rhodnius prolixus in the northern section of South America and formerly in several countries of Central America; Panstrongylus megistus in Brazil; Triatoma dimidiata in Central America, southern Mexico, Colombia and Ecuador
The research projects covered two different model systems of house infestation by triatomine bugs: one in which there is stable domestic and peridomestic colonization (T. infestans in Bolivia and T. dimidiata in Guatemala),[18,19,22] and one in which house invasion is seasonal and domestic colonization appears to be transient with occasional human-vector contact (T. dimidiata in Yucatan, Mexico).[20,21]

Summary

Introduction

With 8–12 million infected people, Chagas disease ranks among the most important infectious diseases in the Americas in terms of disability-adjusted life-years.[1,2] The disease is caused by the protozoan Trypanosoma cruzi which infects at least 150 mammalian species and is mainly transmitted by blood-sucking triatomine bugs.[3] Chagas disease has strong links to rural poverty, poor quality housing, subsistence economies, and marginalized populations.[2] Increased international migration from Latin America to highincome countries has expanded the distribution of human Chagas disease to the global scale through transfusional and vertical transmission. A much longer list of sylvatic triatomine species may infest peridomestic structures and eventually establish domestic colonies, contact humans and transmit

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Discussion

Conclusion