Composition and Vertical Stratification of Phlebotomine Sand Fly Fauna and the Molecular Detection of <i>Leishmania</i> in Forested Areas in Rondônia State Municipalities, Western Amazon, Brazil

Abstract

This study examined sand fly diversity and the natural infection of sand flies by <i>Leishmania</i> in three localities in Rondônia State: Santo Antônio and São Vicente farm, which are anthropized environments, and the Jamari FLONA, which has not been anthropized. Sand flies were collected in canopies and at ground level using CDC light traps and BG-Sentinel CO₂ traps. Female sand flies were grouped into pools that were subjected to DNA extraction and the samples were subjected to PCR to detect and identify <i>Leishmania</i>. A total of 6696 specimens were examined and 52 species were identified. Abundance was greater in canopies than at ground level (<i>n</i> = 5657 and <i>n</i> = 1039, respectively); however, fauna composition was more diverse at ground level. A total of 4870 specimens were collected using CDC light traps and 1826 specimens were collected using BG-Sentinel traps. The presence of <i>Leishmania</i> DNA was detected in 12 pools, and <i>Leishmania</i> species profiles were identified in three of these pools: one pool of <i>Psychodopygus amazonensis</i> and one pool of <i>Psychodopygus chagasi</i> infected with <i>Le. (Vi.) braziliensis</i>, and one pool of <i>Psychodopygus davisi</i> infected with <i>Le. (Le.) amazonensis</i>. Sand flies are sensitive to environmental modification and species diversity is greater in regions that have experienced less anthropization. Although the annual infection rate of cutaneous leishmaniasis is high in Rondônia State, the role that sand flies play in the leishmaniasis transmission cycle remains poorly understood. The high abundance of <i>Ps. davisi</i> and <i>Trichophoromyia auraensis</i> and the presence in these species of natural infection by <i>Leishmania</i> spp. suggest that these species are acting as vectors of tegumentary leishmaniasis in Rondônia.