First description of Leishmania (Viannia) infection in Evandromyia saulensis, Pressatia sp. and Trichophoromyia auraensis (Psychodidae: Phlebotominae) in a transmission area of cutaneous leishmaniasis in Acre state, Amazon Basin, Brazil

Abstract

Studies on the sandfly fauna to evaluate natural infection indexes are still limited in the Brazilian Amazon, a region with an increasing incidence of cutaneous leishmaniasis. Here, by using a multiplex polymerase chain reaction directed to Leishmania kDNA and hybridisation, we were able to identify L. (Viannia) subgenus in 12 out of 173 sandflies captured in the municipality of Rio Branco, Acre state, revealing a positivity of 6.94%. By sequencing the Leishmania 234 bp-hsp70 amplified products from positive samples, infection by L. (V.) braziliensis was confirmed in five sandflies: one Evandromyia saulensis, three Trichophoromyia auraensis and one Pressatia sp. The finding of L. (Viannia) DNA in two Ev. saulensis corresponds to the first record of possible infection associated with this sandfly. Moreover, our study reveals for the first time in Brazil, Th. auraensis and Pressatia sp. infected by L. (Viannia) parasites.

Municipality of Rio Branco, state of Acre, Brazil. Inset shows a satellite image with the distances among the three study areas where sandflies were collected (two collecting points were performed in each area; not indicated in the image). (1) Area I - Chico Mendes Municipal Park (10º02’135’’S, 67º47’716’’W) situated in the Vila Acre district. The park occupies an area of 52 ha and is located along the highway AC-040 and 10 km from the city of Rio Branco. It is considered one of the last remaining areas of primary forest with very important representative species of fauna and flora. (2) Area II - Bosque district (09º55’802’’S, 67º51’763’’W) represents an urban area located near the centre of Rio Branco, where houses have been constructed very close to the Amazon forest with the presence of domestic and wild animals in peri-domicile areas. (3) Area III - Moreno Maia settlement (10º10’357’’S, 67º55’505’’W) is situated along Transacreana Road and represents a rural area far away from the centre of Rio Branco, where the few existing residences are situated near forest with the maintenance of domestic animals in the peri-domicile areas. Source: Rio Branco (67º49’52”S and 9º59’11”W), Google Maps. Image from HM Nogueira Diniz; production service and image treatment, IOC, Fiocruz.