Non-randomized controlled trial of the long-term efficacy of an Ecohealth intervention against Chagas disease in Yucatan, Mexico

PLoS Negl Trop Dis. 2018 Jul 2;12(7):e0006605. doi: 10.1371/journal.pntd.0006605. eCollection 2018 Jul.

Abstract

Non-domiciliated intrusive triatomine vectors are responsible for a low but significant transmission of Trypanosoma cruzi to humans. Their control is a challenge as insecticide spraying is of limited usefulness, and alternative strategies need to be developed for a sustainable control. We performed a non-randomized controlled trial of an Ecohealth intervention based on window insect screens and community participation to reduce house infestation by Triatoma dimidiata in two rural villages in Yucatan, Mexico. Efficacy of the intervention was measured over a three years follow-up period and entomological indicators showed that the proportion of triatomines found inside houses was significantly reduced in houses with insect screens, which effectively kept more bugs on the outside of houses. Using a previously developed model linking entomological data to the prevalence of infection in human, we predicted that the intervention would lead to a 32% reduction in yearly incidence and in the prevalence of T. cruzi infection. The cost for the coverage of all the windows of a house was of comparable magnitude to what families currently spend on various domestic insecticide, and most screens were still in good conditions after three years. In conclusion, the Ecohealth approach proposed here is effective for the long-term and sustainable control of intrusive T. dimidiata vectors in the Yucatan peninsula, Mexico. This strategy may also be easily adapted to other intrusive triatomine species as well as other regions/countries with comparable eco-epidemiological settings, and would be an excellent component of a larger integrated program for the control of a variety of other vector-borne diseases, bringing additional benefits to the communities. Our results should encourage a further scaling-up of our implementation strategy in additional villages in the region.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chagas Disease / parasitology
  • Chagas Disease / prevention & control*
  • Chagas Disease / transmission
  • Housing
  • Humans
  • Insect Control / methods*
  • Insect Vectors / drug effects
  • Insect Vectors / parasitology
  • Insect Vectors / physiology
  • Insecticides / pharmacology
  • Mexico
  • Rural Health
  • Triatoma / drug effects
  • Triatoma / parasitology
  • Triatoma / physiology*
  • Trypanosoma cruzi / drug effects
  • Trypanosoma cruzi / parasitology
  • Trypanosoma cruzi / physiology*

Substances

  • Insecticides

Grants and funding

This investigation received financial support from the UNDP/World Bank/WHO Special Program for Research and Training in Tropical Diseases (TDR)/International Development Research Center (IDRC), Project #A90276. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.