Perfil epidemiológico de la enfermedad de Chagas en la costa sur del Ecuador: estudio piloto de la infección de Trypanosoma cruzi en el vector Triatoma dimidiata

Chagas disease is a prevalent and potentially fatal parasitic infection that affects millions of people, especially in Latin America. The causative agent of the disease is the protozoan Trypanosoma cruzi, transmitted mainly by blood-sucking insect vectors of the subfamily Triatominae. The objective of this study was to analyze the infection by Trypanosoma cruzi in the vector Triatoma dimidiata in a rural area of Southern coastal Ecuador. Triatominae searches were carried out in peridomestic habitats of households located in Bajada de Chanduy, a rural village in the border between Santa Elena and Guayas provinces. Feces and intestinal contents were extracted from the insects and observed in the microscope for the presence of mobile trypanosomes. Approximately 72% of the insects analyzed were infected with trypanosomes. This percentage reflects the occurrence of active foci of T. cruzi and the potential risk that this poses for people living in rural villages in the study area. The trypanosomes that were found infecting the triatomine bugs will be molecularly identified and a study of the genetic variability of the population of T. dimidiata collected at the study site will be carried out in the future. The results of all these analyses will provide a better understanding of the epidemiology of Chagas disease in rural Ecuador, which is an essential step in the development of control and prevention strategies for the transmission of this pathogenic parasite.La Enfermedad de Chagas es una infección parasitaria prevalente y potencialmente fatal, que afecta a millones de personas, especialmente en América Latina. El agente causal de esta enfermedad es el protozoario Trypanosoma cruzi, que es transmitido por insectos hematófagos de la subfamilia Triatominae. El objetivo de este estudio es analizar la infección por Trypanosoma cruzi en el vector Triatoma dimidiata en un área rural de la costa sur del Ecuador. Las búsquedas de triatominos se llevaron a cabo en hábitats peridomésticos de viviendas ubicadas en Bajada de Chanduy, un pueblo rural en el borde entre las provincias de Santa Elena y Guayas. Las muestras de heces y contenido intestinal fueron extraídas de los insectos y observadas en el microscopio para detectar la presencia de tripanosomas móviles. Aproximadamente 72% de los insectos analizados estaban infectados con tripanosomas. Este porcentaje refleja la presencia de focos activos de T. cruzi y el potencial riesgo que esto implica para los habitantes de los pueblos en el área de estudio. Los tripanosomas que se encontraron infectando a los insectos triatominos serán identificados molecularmente y un estudio de la variabilidad genética de la población de T. dimidiata se llevará a cabo en el futuro. Los resultados de todos estos análisis contribuirán a un mayor conocimiento de la epidemiología de la Enfermedad de Chagas en las zonas rurales del Ecuador, lo que constituye un paso esencial en el desarrollo de estrategias de control y prevención para la transmisión de este parásito patógeno

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

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

Seroprevalence and risk factors for infection with Bartonella bacilliformis in Loja province, Ecuador article

© 2018 The Author(s). The seroprevalence and epidemiology of Bartonella bacilliformis infection in the Andean highlands of Ecuador is largely unknown. We conducted a sero-epidemiologic survey of 319 healthy children aged 1-15 years living in six rural, mountain communities in Loja Province, Ecuador. Blood was collected by finger stick onto filter paper and dried, and the eluted sera analyzed for antibodies to B. bacilliformis by rPap31 ELISA. Demographic, entomologic, and household variables were assessed to investigate associated risk factors for antibody seropositivity to B. bacilliformis. Seroprevalence of 28% was found among children in the study communities. Increased risk of seropositivity was associated with the presence of lumber piles near houses. Decreased risk of seropositivity was observed with the presence of animal waste and incremental 100 meter increases in elevation. Although investigation of clinical cases of Carrion\u27s disease was not within the scope of this study, our serology data suggest that infection of children with B. bacilliformis is prevalent in this region of Ecuador and is largely unrecognized and undiagnosed. This study highlights the need to further investigate the prevalence, pathogenesis, epidemiology, and disease impact of this pathogen in Ecuador

Abundance, Natural Infection with Trypanosomes, and Food Source of an Endemic Species of Triatomine, Panstrongylus howardi (Neiva 1911), on the Ecuadorian Central Coast

The elimination of domestic triatomines is the foundation of Chagas disease control. Regional initiatives are eliminating introduced triatomine species. In this scenario, endemic triatomines can occupy the ecological niches left open and become a threat to long-term Chagas disease control efforts. This study determined the abundance, colonization, and Trypanosoma cruzi infection rate of the endemic Panstrongylus howardi in 10 rural communities located in Ecuador's Manabí Province. In total, 518 individuals of P. howardi were collected. Infestation indices of 1.4% and 6.6% were found in the domestic and peridomestic environments, respectively. We determined a T. cruzi infection rate of 53.2% (N = 47) in this species. P. howardi has a high capacity to adapt to different habitats, especially in the peridomicile. This implies a considerable risk of transmission because of the frequency of intradomicile invasion. Therefore, this species needs to be taken into account in Chagas control and surveillance efforts in the region