| Trypanosoma cruzi, the causative agent of Chagas disease, is a protozoan parasite transmitted by insect vectors of the subfamily Triatominae. Human infection occurs throughout Latin America. The epidemiology of T. cruzi infection on Ecuador has not been widely studied. This is a cross-sectional study of T. cruzi seroprevalence and household risk factors for T. cruzi seropositivity in 14 rural communities in 3 provinces of Ecuador. 3,286 subjects from 997 households were included in the study. Seroprevalence of T. cruzi was 5.7%, 1.0%, and 3.6% in the sampled communities of the Manabi, Guayas, and Loja provinces, respectively. Seroprevalence increased with increasing age in the provinces of Manabi and Guayas, while in Loja the highest prevalence was seen in children younger than 10 years. In the coastal provinces of Manabi and Guayas, 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 [1.31, 6.04]), and the presence of firewood in the peridomicile area (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 province of Loja, living in a house with adobe walls and living in the same household as another seropositive individual were the only factors predictive of T. cruzi seropositivity. The risk of seropositivity was more than two times greater for an individual living in a household with another seropositive person in this region.; Clustering of seropositives within households was not observed in the coastal region after adjustment for known household risk factors for T. cruzi infection. In conclusion, risk factors for T. cruzi transmission in Ecuador varied by geographic region, likely due to differing behavior of the triatomine vector species in each region. These findings illustrate that an understanding of the transmission dynamics of T. cruzi in a particular area are necessary for the development of effective Chagas disease control strategies in those areas. |
