Enzootic transmission of Leishmania spp. in gallery forests of the Brazilian Cerrado

Abstract

Gallery forests harbor mammals and sand flies that may be involved in the transmission of Leishmania spp. parasites. Characterizing the enzootic cycles of Leishmania spp. is essential for understanding its transmission dynamics. We analyzed the presence of Leishmania spp. in mammals and sand flies in gallery forests during the dry season in the Cerrado. Four gallery forests were investigated in May and September 2014. Our capture effort included 1,280 HP trap-nights, 16 Shannon trap-nights for sand flies, and 5,120 trap-nights for mammals. After identifying the mammalian and sand fly species, SSU rRNA and ITS-1 polymerase chain reaction (PCR) were used to detect Leishmania spp. A total of 1,209 sand flies belonging to 13 species were captured, mainly Bichromomyia flaviscutellata. Leishmania spp. DNA was not detected in the analyzed sand fly females. PCR analysis of 153 mammals revealed Leishmania spp. in 20 samples (13%) in May (early dry season), when the infection rate was 31% in one gallery forest. The host species were Rhipidomys macrurus, Gracilinanus agilis, and Didelphis albiventris. We observed a low frequency of mammals infected with Leishmania spp., which was not detected in sand flies. Our results indicate that Leishmania spp. infection is higher in mammals during the early dry season in Cerrado gallery forests.