Beating the odds: Sustained Chagas disease vector control in remote indigenous communities of the Argentine Chaco over a seven-year period

摘要

Author summary Efforts to prevent the transmission of the parasite that causes Chagas disease have been directed at eliminating its insect vector species from human dwellings via insecticide applications. The outcome of these interventions has usually been measured through vector-related metrics in prospective studies ranging up to a few years. Longer-term intervention studies that additionally monitor other social determinants of house infestation, such as housing quality and population movement, are lacking. Our seven-year study addresses this gap in a remote rural area of the Argentine Chaco inhabited by deprived indigenous communities. We show sustained vector control headed towards local elimination despite the highly adverse social context and the occurrence of moderate pyrethroid resistance in vector populations. Housing-quality dynamics and household mobility displayed complex patterns that may affect domestic triatomine populations. Household mobility within the area was intense: movers usually torn down their previous precarious houses and built new, equally precarious houses. Housing dynamics included structural improvements, disappearance and construction of new dwellings elsewhere within the study area. We infer that these eco-bio-social factors, including the broad geographic coverage of sustained vector control creating a peripheral buffer zone, substantially increased the long-term effectiveness of the intervention program.