Risk factors for intradomiciliary infestation by the Chagas disease vector Triatoma dimidiatain Jutiapa, Guatemala

Abstract

Seventeen variables were evaluated as possible risk factors for the intradomiciliary infestation with Triatoma dimidiata in 644 houses in Jutiapa, Guatemala. During 2004 the houses were assessed for vector presence and evaluated for hygiene, cluttering, material comfort, construction conditions and number of inhabitants, among other factors. Chi-square analysis detected significant associations between vector presence and eight variables related to domestic sanitary and construction conditions. Log-linear models showed that regardless of the age of the house, the odds of vector presence were 4.3 and 10 times lower in houses with a good socioeconomic status compared with poor and very poor houses respectively. Log-linear models also pointed to a greater chance of vector presence when walls lacked plastering (3.85 times) or walls had low quality-incomplete plastering (4.56 times), compared with walls that were completely plastered. Control strategies against T. dimidiata should include the introduction of better-quality but inexpensive plastering formulations and better sanitation practices should also be promoted among the population. Such control strategies should not only reduce or eliminate infestation, but also prevent vector reinfestation.

Vector Blood Meals Are an Early Indicator of the Effectiveness of the Ecohealth Approach in Halting Chagas Transmission in Guatemala

“…6 Indeed, unplastered or deteriorated plastered walls and poor hygienic conditions have been shown to be the most important out of many factors in predicting T. dimidiata house infestation in Guatemala. 7 We believe that encroachment and deforestation reduces sylvan blood meal sources and replaces those with human and domestic animal blood sources, which could support a higher insect density.…”

Ecohealth Interventions Limit Triatomine Reinfestation following Insecticide Spraying in La Brea, Guatemala

“…Beginning in 2005, interventions also focused on community education regarding Chagas disease and on making houses resistant to reinfestation by T. dimidiata through hygienic and targeted home improvements. 17,18 Interventions in 2008 focused on limiting vector access to alternative blood meal sources within the home and on limiting vector survival in peridomestic habitats. 18 Home improvements included plastering of interior walls (2005) and replacing dirt floors with a cement-like floor material made of volcanic ash and lime (2008) to eliminate potential areas of refuge for the vector within the home, as well as limit vector access to soil particles often used for camouflage.…”

“…Five entomological and socio-economic surveys were completed over the 2002-2009 study period (Table 1) to evaluate the effectiveness of the combined insecticide spraying and Ecohealth intervention program and provide insight into the environmental and socio-economic factors associated with vector reinfestation. 17,18 Five individuals from the Universidad de San Carlos and five health officials from the Guatemalan Chagas Program administered the questionnaire and performed the entomological surveys. All homesteads within the village were assigned a house number and the geographic coordinates of each home were recorded using a handheld global positioning system (GPS) receiver.…”

Triatoma dimidiata in Colombia. Distribution, ecology and its epidemiological importance

“…En este amplio territorio se la puede encontrar en hábitats silvestres, en el peridomicilio y en el domicilio, y ha habido reportes de su presencia en el área urbana en diferentes países de América Central, así como en Colombia y en Ecuador (14)(15)(16)(17). Con frecuencia se reportan poblaciones en los tres hábitats en una misma área geográfica, en tanto que en Belice, por ejemplo, solo se la ha encontrado en condición silvestre y, ocasionalmente, en el peridomicilio (18).…”

“…Las condiciones socioeconómicas son determinantes para la infestación domiciliaria y, en algunos estudios, se ha reportado que la probabilidad de encontrar individuos de T. dimidiata es 4,3 a 10 veces mayor en viviendas con condiciones socioeconómicas deficientes que en aquellas con buenas condiciones (17).…”