Household Risk Factors for Trypanosoma Cruzi Seropositivity in Two Geographic Regions of Ecuador

Abstract

Few studies on the relationship between environmental factors and Trypanosoma cruzi transmission have been conducted in Ecuador. We conducted a cross-sectional study of household risk factors for T. cruzi seropositivity in 2 distinct geographical regions of Ecuador. Exposure information was collected via household surveys, and subjects were tested for serological evidence of T. cruzi infection. In total, 3,286 subjects from 997 households were included. In the coastal region, factors associated with seropositivity were living in a house with a palm roof (odds ratio [OR] = 2.63, 95% confidence interval, [1.61. 4.27]), wood walls (OR = 5.75 [2.04, 16.18]), or cane walls (OR = 2.81 11.31, 6.04]), and the presence of firewood in the peridomicile (OR = 2.48 [1.54, 4.01]). Accumulation of trash outside the home was associated with a reduced risk of seropositivity (OR = 0.25 [0.12, 0.51]). In the Andean region, living in a house with adobe walls was the only factor predictive of T. cruzi seropositivity. In conclusion, risk factors for T. cruzi transmission in Ecuador varied by geographic region, probably because of differing behavior of the triatomine vector species in each region. An understanding of the transmission dynamics of T. cruzi in a particular area is necessary for the development of effective Chagas disease control strategies in those areas.

Absence of domestic triatomine colonies in an area of the coastal region of Ecuador where Chagas disease is endemic

“…However, in many areas of Ecuador, systematic studies have neither been conducted nor published. The low number of triatomines found in our study is in contrast with the parasitological analyses obtained from mammals collected at the same time, which are similar with the T. cruzi infection levels found in mammals in other areas endemic for Chagas disease, such as southern Ecuador (Pinto et al 2006, Black et al 2007, 2009.…”

“…Indeed, many studies have implicated housing characteristics as risk factors for infection with T. cruzi. However, despite similar housing conditions and socio-economic status, the seroprevalence of T. cruzi varies widely along the coast of Ecuador (Black et al 2007). A seroprevalence survey conducted in Guayas in conjunction with the present study found an overall seroprevalence of 1%, with a prevalence of 3% among subjects aged 60 years and older (Black et al 2009).…”

Seroprevalencia de la infección por Trypanosoma cruzi y factores asociados en un área endémica de Venezuela

“…Por ejemplo, las casas con paredes de adobe y caña o con techos de palma, así como la presencia de leña en el peridomicilio fueron asociadas con un mayor riesgo de seropositividad; mientras que la acumulación de basura, materia orgánica, piedras y madera, el número de corrales de animales en el peridomicilio estuvieron asociados negativamente con la seropositividad 32,33 . En este trabajo observamos una asociación positiva entre el acúmulo de artefactos viejos, desechos, materiales de construcción, basura y la limpieza inadecuada del domicilio con la probabilidad de los habitantes de la vivienda de ser seropositivos.…”

Seroprevalence of Trypanosoma cruzi in Rural Ecuador and Clustering of Seropositivity within Households

“…These two regions are geographically distinct with different insect vectors of T. cruzi , and a previous analysis of these data showed that household risk factors for T. cruzi differed between the two regions. 11 In the previous analysis, type of materials used in the construction of roofs (palm or tile versus metal) and walls (cane or adobe versus cement) of houses were identified as risk factors for T. cruzi seropositivity. The presence of firewood and trash in the peridomicile area were additionally associated with seropositivity in the coastal provinces but not in the highlands.…”