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

Abstract

Abstract. We performed a cross-sectional study of Trypanosoma cruzi seroprevalence in 14 communities in three provinces of Ecuador and estimated the magnitude of the association of seropositive individuals within households. A total of 3,286 subjects from 997 households were included. Seroprevalence was 5.7%, 1.0%, and 3.6% in subjects in the Manabí, Guayas, and Loja provinces, respectively. Seroprevalence increased with increasing age in Manabí and Guayas, whereas in Loja, the highest prevalence occurred in children ≤ 10 years of age. In the coastal provinces, clustering of seropositives within households was not observed after adjustment for other household factors. However, in the Andean province of Loja, the odds of seropositivity were more than two times greater for an individual living in a household with another seropositive person. Our results indicate that transmission of T. cruzi is ongoing in Ecuador, although intensity of transmission and mechanisms of interaction between humans and the insect vectors of disease vary between geographic regions.

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

“…In contrast, the prevalence of T. cruzi seropositivity in the neighbouring coastal province of Manabí was 5.7%, with prevalences reaching as high as 11% among subjects older than 60 years of age. The low seroprevalence reported in Guayas, particularly among young age groups as reported by Black et al (2009), fits with the absent triatomine infestation found in this study.…”

“…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). In contrast, the prevalence of T. cruzi seropositivity in the neighbouring coastal province of Manabí was 5.7%, with prevalences reaching as high as 11% among subjects older than 60 years of age.…”

A National Survey to Determine Prevalence of Trypanosoma cruzi Infection Among Pregnant Women in Ecuador

“…1 It is estimated that 200,000 people are infected with T. cruzi in Ecuador, 2 where most provinces located on the Pacific coast as well Loja in the southern highlands have, for many decades, been known to be endemic for Chagas disease and continue to be active transmission foci. 3,4 Meanwhile, sylvatic foci were detected in the northern Ecuadorian Amazon region during the 1990s, 5 and additional studies have shown that this region is very active for T. cruzi transmission. [6][7][8] However, despite punctual knowledge at the local scale, the global epidemiological situation of Chagas disease in Ecuador remains largely uncharacterized: no countrywide study exists to provide a global estimate of prevalence for T. cruzi infection, many areas remain unstudied, and particularly little is known regarding congenital transmission.…”

“…Furthermore, they should include Loja province, a key active endemic region in the highlands. 4 Generating epidemiological information from the high-risk areas should be a priority to inform the most cost-effective strategies aimed at eliminating mother-to-child transmission of Chagas disease in Ecuador. Finally, an education component designed to inform the population about Chagas disease and the risk of congenital transmission is required, which is highlighted by the results of our surveys.…”

Clinical, electrocardiographic and echocardiographic abnormalities in Latin American migrants with newly diagnosed Chagas disease 2005-2009, Barcelona, Spain

“…Several articles published, although not in a conclusive way, suggest the opposite. A familial aggregation could exist among Chagas cardiomyopathy cases due to a higher number of mother-to-child transmissions by highly infectious T. cruzi strains or due to a longer infection period [15,16]. This fact could be explained by taking into account that the infected individual, usually asymptomatic and mainly with normal cardiac tests, was considered as "reference case" and a T. cruzi active research was done among close asymptomatic relatives.…”