Feeding sources and trypanosome infection index of Rhodnius pallescens in a Chagas disease endemic area of Amador County, Panama

Abstract

SUMMARYThe sylvatic triatomine Rhodnius pallescens is considered to be the most important and widespread vector of Trypanosoma cruzi and Trypanosoma rangeli in Panama. However, its behavior and biological characteristics have only been partially investigated. Thus, to achieve sustainable and efficient control over Chagas disease in Panama, a better understanding of the ecology and biology of R. pallescens is essential. In this study we evaluated R. pallescens host feeding sources using a dot-blot assay, and the trypanosome infection index by PCR analysis in a Chagas disease endemic area of central Panama. It was found that in peridomestic palm trees, 20.3% of the examined bugs had fed on opossums (Didelphis marsupialis). However, we observed an increased anthropophagy (25.4%) for those bugs collected inside houses. Considering the domestic and peridomestic habitats as a whole, the proportion of collected R. pallescens infected with trypanosomes was 87.4%. In the two habitats the predominant infection was with T. cruzi (80-90%). Between 47-51% of the analyzed triatomines were infected with T. rangeli. Mixed infections (40-51%) were also detected. These findings provide a better basis for the implementation of a rational control and surveillance program for Chagas disease in regions where R. pallescens is endemic.

Entomological Indices, Feeding Sources, and Molecular Identification of Triatoma phyllosoma (Hemiptera: Reduviidae) One of the Main Vectors of Chagas Disease in the Istmo de Tehuantepec, Oaxaca, Mexico

“…16 Rhodnius pallescens collected from peridomestic palm trees had fed on opossums, whereas insects collected inside houses showed increased anthropophagy; however, no significant difference in the infection index was observed between the two habitats. 17 Belminus herreri was positive for only one feeding source, Blattidae. 18 In localities of Jalisco, Mexico, T. longipennis had different preferences depending on the habitat.…”

Conocimientos y factores de riesgo relacionados con la enfermedad de Chagas en dos comunidades panameñas donde Rhodnius pallescens es el vector principal

“…Las características clínicas y epidemiológicas particulares que adopta esta zoonosis en el país, han sido estudiadas en los últimos años por varios autores (2)(3)(4)(5)(6)(7). Si bien se han reportado condiciones eco-epidemiológicas apropiadas para su transmisión en casi todas las provincias, la infección humana es más frecuente en las áreas rurales que bordean el Canal de Panamá (1,8), en el distrito de Chepo al este de la provincia de Panamá (9) y en el norte del distrito de Santa Fe en la provincia de Veraguas (7).…”

“…Rhodnius pallescens es considerado el vector principal de la enfermedad de Chagas en la mayoría de las áreas endémicas estudiadas (3,4,9,10). Este triatomino presenta esencialmente hábitos silvestres, aunque frecuentemente se desplaza al domicilio y peridomicilio en busca de alimento, atraído por la luz u otros factores no definidos totalmente (3,11).…”

“…A diferencia de otros triatominos de Centroamérica y Suramérica, la colonización de las viviendas por R. pallescens es un evento poco común que amerita evaluaciones prospectivas urgentes. Por otra parte, la infestación domiciliaria por pocos insectos, la mayoría adultos infectados con T. cruzi, es una condición frecuente en las comunidades aquí estudiadas (3,4).…”

Detection of Wolbachia Bacteria in Multiple Organs and Feces of the Triatomine Insect Rhodnius pallescens (Hemiptera, Reduviidae)

“…Its capacity to invade houses located near its natural habitat, the royal palm tree (Attalea butyracea), and to transmit T. cruzi and Chagas' disease to humans has been well documented in Panama (4,23,32). Wolbachia was previously found in only one individual of R. pallescens that was described in a list of Panamanian species (41).…”