Molecular Mass Screening to Incriminate Sand Fly Vectors of Andean-type Cutaneous Leishmaniasis in Ecuador and Peru

Abstract

Sand flies from the Andean areas of Ecuador and Peru were examined for Leishmania infections by using our recently established molecular mass screening method. Leishmanial minicircle DNA-positive sand flies were detected in 3 of 192 and 1 of 462 samples from Ecuador and Peru, respectively. Sand fly species were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the 18S ribosomal RNA (rRNA) gene, and the positive flies were Lutzomyia (Lu.) ayacuchensis and Lu. peruensis, respectively. Furthermore, cytochrome b and mannose-phosphate isomerase gene sequence analyses identified the parasites from Ecuador and Peru as Leishmania (Leishmania) mexicana and L. (Viannia) peruviana, respectively. Thus, the mass screening method was confirmed to be a powerful tool for sand fly research.

Development of a loop-mediated isothermal amplification method for rapid mass-screening of sand flies for Leishmania infection

“…In the present study, the applicability of the colorimetric MG-based LAMP assay for detection This result was consistent with previous reports from the same study areas (Hashiguchi et al, 1991;Kato et al, 2005Kato et al, , 2008. Hence, in this proof-of-concept study, the LAMP method using MG dye was found to be a rapid, sensitive and high-throughput screening tool for the detection of sand flies infected with the Leishmania DNA in endemic areas.…”

“…(L.) mexicana in both Alausi and Chanchan, as well as other Andean endemic areas of Ecuador (Takaoka et al, 1990;Kato et al, 2005Kato et al, , 2008.…”

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 .…”

“…The only incriminated vector species is Lu. ayacuchensis, and the ratio infected by L. (L.) mexicana is high (1-8%) in highland areas, which is uncommon in most endemic areas of Ecuador (Takaoka et al, 1990;Gomez and Hashiguchi, 1991;Hashiguchi et al, 1991;Kato et al, 2005Kato et al, , 2008a. Therefore, distribution of the vector species is a major risk factor for the endemicity of leishmaniasis.…”

“…In the Andean highlands (Alausi, Chanchan, and Huigra), L. (L.) mexicana is endemic and Lu. ayacuchensis is incriminated as the vector species (Takaoka et al, 1990;Gomez and Hashiguchi, 1991;Hashiguchi et al, 1991;Kato et al, 2005Kato et al, , 2008a. No Andean type of cutaneous leishmaniasis (CL) cases caused by L. (L.) mexicana was reported in the lower areas, including Olympo, Ochoa, Naranjapata, and Ventura.…”