Epidemiology of Andean Cutaneous Leishmaniasis: Incrimination of Lutzomyia Ayacuchensis (Diptera: Psychodidae) as a Vector of Leishmania in Geographically Isolated, Upland Valleys of Peru

Abstract

The southernmost limit of the distribution of endemic Andean cutaneous leishmaniasis (CL), commonly known as Uta, is localized in the western Andean valleys of Ayacucho, Peru. This area is completely isolated from other regions endemic for this disease. Identification of the insect vector for Andean CL was carried out by combining entomologic and parasitologic approaches. Two Lutzomyia species were captured: Lutzomyia ayacuchensis and Lu. noguchii. The former species was considered responsible for transmission of Leishmania because 1) there was a coincidence in space and time between the presence of this insect and the distribution of Andean CL, 2) it was shown to be highly anthropophilic, 3) Leishmania parasites of the subgenus Viannia were detected by a specific polymerase chain reaction assay, 4) promastigotes isolated from this insect were shown by multilocus enzyme electrophoresis and molecular karyotyping to belong to the same deme of Leishmania (Viannia) peruviana as the one circulating in humans living in the study area, and 5) the complete cycle of L. (V.) peruviana was observed in experimental infections of Lu. ayacuchensis. Parasite and vector homogeneity found in Ayacucho contrasted with the heterogeneity reported for other areas endemic for Andean CL. The potential influence of ecologic determinants on this geographically isolated area is discussed.

Natural Leishmania Infection of Lutzomyia auraensis in Madre de Dios, Peru, Detected by a Fluorescence Resonance Energy Transfer–Based Real-Time Polymerase Chain Reaction

“…4,6,7 In Peru, four species have been incriminated as vectors of L. (V.) peruviana, and all are in the Andean Mountain regions. [8][9][10][11] However, little is known regarding vectors of NWTL in the Peruvian Amazon Basin despite the large number of human cases reported. 8,9,11 Vector surveillance studies are often focused on studying the distribution of potential vectors and the prevalence of Leishmania infections in field-captured sand flies.…”

“…[8][9][10][11] However, little is known regarding vectors of NWTL in the Peruvian Amazon Basin despite the large number of human cases reported. 8,9,11 Vector surveillance studies are often focused on studying the distribution of potential vectors and the prevalence of Leishmania infections in field-captured sand flies. These studies are critical to better understand the dynamics of disease transmission and to identify new parasite-vector associations.…”

Vectores de la leishmaniasis tegumentaria y la Enfermedad de Carrión en el Perú: una actualización

“…Fue descrita a partir de ejemplares capturados en áreas endémicas de leishmaniasis de las provincias de Lucanas y Parinacochas (Ayacucho), entre los 1400 y los 2950 m de altitud (56) . También se ha reportado su presencia en los departamentos de Ancash, La Libertad, Cajamarca y Piura (10,57) , así como en el sur de Ecuador (24) .…”

Distribution of Lutzomyia ayacuchensis, the vector of Andean-type cutaneous leishmaniasis, at different altitudes on the Andean slope of Ecuador

“…During our research activities, we have discovered a form of the disease in people living on the Andean plateau/valleys; the disease form is very similar to 'Peruvian uta' but the causative agent and vector are completely different (Takaoka et al, 1990;Gomez and Hashiguchi, 1991;Kato et al, 2005Kato et al, , 2008a (Davies et al, 1993;Perez et al, 1994Perez et al, , 2007Caceres et al, 2004;Kato et al, 2008aKato et al, , 2011. In Ecuador, however, two species of the genus Leishmania, Leishmania (Leishmania) mexicana and L. (L.) major-like, seemed to be involved in Andean highland leishmaniasis .…”