Leishmania spp. DNA in Sand Flies in a Transition Area of the Cerrado and Atlantic Forest biomes, Mato Grosso do Sul, Brazil

Leishmaniases are infectious diseases whose vectors are female sand flies that depend on the blood of vertebrates for egg maturation. In this study, we investigated the sand fly species and DNA from Leishmania spp. This entomological/epidemiological study was conducted in a rural area in Nova Andradina, Mato Grosso do Sul, Brazil. From March 2019 to February 2020, five modified Falcão light traps were installed at night once a month. The collected insects were separated by sex into pools of 10 specimens. A sample was used for species identification via microscopic analysis, and another sample was used to detect the DNA of Leishmania in females via polymerase chain reaction (PCR). A total of 42,933 insects were collected, 77.6% (n = 33,313) of which were female. A total of 4,993 (11.6%) insects were identified, most were Nyssomyia neivai (n = 4,839; 96.9%). For PCR, 4,130 (9.6%) insects were analyzed, and four pools were positive for Leishmania spp. (with a natural infection rate of 0.1%). When the number of sand flies collected and the climatic variables were correlated, a significant difference was detected when precipitation > 60 mm (p = 0.0314) and relative humidity ≤ 60% (p = 0.0201). The analyzed area is inhabited by one of the main vectors of cutaneous leishmaniasis in Brazil, and we also found that some specimens were infected with Leishmania DNA, which might favor the occurrence of the disease in the region. This information is essential for understanding the dissemination of leishmaniasis and planning actions to prevent in the municipality.