Entomological aspects of leishmaniasis transmission in the urban area of Teófilo Otoni, a municipality endemic for the disease in the Brazilian state of Minas Gerais.

ABSTRACT

Brazil is endemic for both visceral (VL) and cutaneous (CL) clinical forms of leishmaniasis, poverty-associated diseases with worldwide distribution. Leishmania parasites are the etiological agents of leishmaniases, which are transmitted to humans through the bites of infected phlebotomine sand flies. From 2018 to 2023, 15 cases of VL and 129 cases of CL were reported in Téofilo Otoni, an important economic center in the Brazilian state of Minas Gerais. Owing to the lack of data on the entomological fauna, the present study aimed to clarify this main aspect of leishmaniasis. From May, 2021 to April, 2023, entomological captures were performed monthly in ten neighborhoods in Teófilo Otoni. The influence of bioclimatic variables on insect populations was evaluated, and natural infection by Leishmania spp. was investigated using molecular methods. A total of 306 specimens of 12 species of phlebotomine sand fly were collected. The majority (91.6%) were proven or putative vectors of leishmaniasis agents. The population of insects tended to increase during the cooler and drier months. Although Leishmania infection was not detected in any of the samples, the presence of vectors provides conditions for the maintenance and expansion of the transmission cycle of leishmaniasis in Teófilo Otoni.