Vector competence of some Neotropical sandflies for the Leishmania (Viannia) braziliensis complex

Abstract

To evaluate the vector competence of some Lutzomyia spp. (Diptera: Psychodidae) for Leishmania (Viannia) spp. (Kinetoplastida: Trypanosomatidae), experimental infections of anthropophilic sandflies from the Colombian Pacific coast were performed, through membrane feeding and xenodiagnosis on hamsters infected with Le. (V.)braziliensis or Le. (V.)panamensis. Wild-caught or F1 generation females of Lutzomyia gomezi, Lu. hartmanni, Lu.panamensis and Lu.trapidoi were allowed to feed on hamster lesions and then maintained at 26 degrees C and > 80% r.h. on a sugar-water diet until dissection on the fifth day post-infection (p.i.). Despite similar infection rates (range 37-44%) in both Lu.gomezi and Lu.trapidoi, infections were heavier (> 100 parasites) in the latter species. Infections of Lu.trapidoi with Le.braziliensis (n = 21) and Le.panamensis (n = 27) showed parasite migration toward the foregut, with promastigote colonization of the stomodeal valve and appearance of infective forms. In contrast, infections of Lu.gomezi with Le.braziliensis (n = 10) and Le.panamensis (n = 5) were light (< 50 parasites) and usually restricted to the pylorus. In Lu.hartmanni, only a few promastigotes were found in the pylorus and midgut of 3/8 specimens infected with Le.braziliensis, and no Le.panamensis developed (n = 19). By day 5 p.i., promastigote colonization of the hind- and midgut by Le.panamensis was observed in 2/4 Lu.panamensis but not Le.braziliensis (n = 3). It was concluded that Lu.trapidoi is a more efficient vector than Lu.gomezi for both Le.braziliensis and Le.panamensis, and that Lu.hartmanni and Lu.panamensis are of minor importance for Leishmania transmission in this endemic area.

Presencia en el peridomicilio de vectores infectados con Leishmania (Viannia) panamensis en dos focos endémicos en el occidente de Boyacá, piedemonte del valle del Magdalena medio, Colombia

“…trapidoi es un vector confirmado de L. (V.) panamensis en otros focos de leishmaniasis cutánea en Colombia (11,29,35,36,), Panamá (37) y Ecuador (38). Es antropofílica y su capacidad para soportar el desarrollo de L. (V.) panamensis se ha confirmado en el laboratorio (39). En el presente estudio, L. trapidoi fue la especie más abundante en el intradomicilio en ambos municipios y en el peridomicilio, también, presentó una abundancia importante.…”

“…La presencia de alimento sanguíneo en la hembra de L. gomezi encontrada infectada en este estudio llevaría a discutir dos posibilidades: la primera es que la hembra se haya alimentado horas antes de la captura de un reservorio infectado o que se haya infectado con Leishmania en una primera alimentación y que acabara de tomar su segunda o tercera alimentación de sangre, lo cual colocaría a esta especie como un vector eficiente de Leishmania (48). Se ha demostrado en infecciones experimentales que L. gomezi permite el completo desarrollo de L. (V.) panamensis en su tracto digestivo (39,52).…”

Phylogeography of the Lutzomyia gomezi (Diptera: Phlebotominae) on the Panama Isthmus

“…Alongside Lu. gomezi other Lutzomyia species vectors have been caught in the same place and associated with a focus of cutaneous leishmaniasis infection in other American countries, incriminating this species with high potential in the transmission of the disease [2,10-14]. …”

First report of Warileya rotundipennis (Psychodidae: Phlebotominae) naturally infected with Leishmania (Viannia) in a focus of cutaneous leishmaniasis in Colombia

“…panamensis have been previously incriminated as vectors of Leishmania braziliensis and Leishmania panamensis , respectively (Morales et al, 1981; Hashiguchi et al, 1985; Travi et al, 1988; Jaramillo et al, 1994; Rodriguez et al, 1999; Christensen et al, 1983). Although N. trapidoi was found infected with Leishmania of the Viannia subgenus in this study, the limited number of specimens of this species found inside of houses contrasted with the marked abundance of W. rotundipennis.…”