Positive deviance study to inform a Chagas disease control program in southern Ecuador

Chagas disease is caused by Trypanosoma cruzi, which is mainly transmitted by thefaeces of triatomine insects that find favourable environments in poorly constructedhouses. Previous studies have documented persistent triatomine infestation in housesin the province of Loja in southern Ecuador despite repeated insecticide andeducational interventions. We aim to develop a sustainable strategy for theinterruption of Chagas disease transmission by promoting living environments that aredesigned to prevent colonisation of rural houses by triatomines. This study usedpositive deviance to inform the design of an anti-triatomine prototype house byidentifying knowledge, attitudes and practices used by families that have remainedtriatomine-free (2010-2012). Positive deviants reported practices that includedmaintenance of structural elements of the house, fumigation of dwellings and animalshelters, sweeping with "insect repellent" plants and relocation of domestic animalsaway from the house, among others. Participants favoured construction materials thatdo not drastically differ from those currently used (adobe walls and tile roofs).They also expressed their belief in a clear connection between a clean house andhealth. The family''s economic dynamics affect space use and must be considered in theprototype''s design. Overall, the results indicate a positive climate for theintroduction of housing improvements as a protective measure against Chagas diseasein this region.