Geographic Distribution of Leishmania Species in Ecuador Based on the Cytochrome B Gene Sequence Analysis

Abstract

A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas.

Eco-epidemiological aspects, natural detection and molecular identification of Leishmania spp. in Lutzomyia reburra, Lutzomyia barrettoi majuscula and Lutzomyia trapidoi

“…Leishmania braziliensis se ha encontrado en la provincia de Pichincha en pacientes con leishmaniasis cutánea en las localidades de San Miguel de Los Bancos, Puerto Quito y Pedro Vicente Maldonado; esta especie se había registrado ya en la Amazonia y en la costa ecuatoriana (21). En el presente estudio, se detectó en ejemplares de Lu.…”

“…amazonensis en focos endémicos depende de las especies dominantes primarias o secundarias (21), pero para confirmar esta hipótesis es necesario evaluar en campo, entre otras variables ecológicas, la preferencia alimentaria, la tasa de picadura y la actividad nocturna. La presencia de ADN de Leishmania en el abdomen de una hembra evidenció que hubo multiplicación del parásito en el mesenterón, lo que desde el punto de vista biológico es clave cuando se evalúa el papel de una especie de flebotomíneos como vector local.…”

“…y su tipificación en flebotomíneos, se han empleado el gen citocromo b (Cyt b) y la subunidad pequeña ribosómica de la región del ARN (SSU-rRNA) (21). En el presente trabajo, se utilizó el gen espaciador interno de la transcripción del ARN ribosómico, unidad I (ITS1), propuesto recientemente para una detección más sensible de Leishmania spp.…”

Coinfection of Leishmania guyanensis and Human Immunodeficiency Virus–Acquired Immune Deficiency Syndrome: Report of a Case of Disseminated Cutaneous Leishmaniasis in Ecuador

“…2 Leishmania guyanensis was identified as the causative species, which he probably contracted while working in the endemic area for CL, where the dominant parasites are L. guyanensis and L. panamensis. 9,11 In coinfected individuals from Brazil, Bolivia, Argentina, and French Guyana, the infecting agents were identified as L. guyanensis and L. braziliensis; also, a viscerotropic variant of Leishmania chagasi was found in cutaneous lesions of an HIV-positive patient. 2,3 The severity and characteristics of the lesions depend more on the degree of immunosuppression rather than the infecting Leishmania species.…”

“…have been identified from human lesions, with the species Leishmania panamensis and L. guyanensis, being predominant in the subtropical and tropical lowlands of the Pacific coastal region. [9][10][11] Regarding HIV infection in Ecuador, data from the Ministry of Public Health (MSP), inform that since 1984, the year in which the first case of HIV was detected, until 2011, the mean prevalence of infection in the population was 0.24%; the registered number of HIV cases was 22,177, of which 9,911 are now acquired immune deficiency syndrome (AIDS) cases. 12 By 2014, MSP estimated that the number of people living with HIV was 33,000 (25,000-46,000).…”