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

Distribution of the vector species is a major risk factor for the endemicity of leishmaniasis. In the present study, the vertical distribution of Lutzomyia (Lu.) ayacuchensis, the vector of Leishmania (Leishmania) mexicana in the Ecuadorian Andes, was surveyed at different altitudes (300–2500 m above sea level) of the Andean slope. The vector species Lu. ayacuchensis was identified at an altitude of 650 m and a higher areas, and higher distribution ratio of the species was observed at higher altitudes. In addition, high ratios of L. (L.) mexicana infection were detected in higher areas, but none in lower populations of sand flies. Since an association between sand fly populations and vector competence is suggested in Lu. ayacuchensis, haplotype analysis was performed on the species from different altitudes of the study areas; however, no apparent difference was observed among populations. These results suggested that Lu. ayacuchensis in Andean slope areas of Ecuador has the potential to transmit L. (L.) mexicana and spread leishmaniasis in these areas.