Sand fly (Diptera: Psychodidae: Phlebotominae) species composition in an area with a recent American Tegumentary Leishmaniasis outbreak in Minas Gerais, Brazil

Abstract

American tegumentary leishmaniasis (ATL) constitutes an infectious, non-contagious pathology that manifests as ulcerative lesions on the integumentary system and mucosal surfaces. The causative agents are parasites belonging to the genus Leishmania (Protozoa: Kinetoplastida: Trypanosomatidae). In Brazil, the principal ATL agents include Leishmania (Leishmania) amazonensis, Leishmania (Viannia) guyanensis, and Leishmania (Viannia) braziliensis. ATL transmission to humans occurs via the hematophagous activity of phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae). Despite the endemic status of ATL in Brazil, a notable outbreak occurred in the municipality of Montes Claros (Minas Gerais state), yielding 509 documented cases over a triannual period (from 2019 to 2021). In light of the absence of contemporary entomological data in that region, a survey was performed involving monthly collections over 1-yr (from June 2022 to May 2023) across 6 sylvan environments within the peri-urban area of the city, where ATL cases were reported. A total of 3,342 phlebotomine sand flies, representing 10 genera and 29 species, were collected and identified to the species level. Three ATL vectors were identified with the following relative abundances: Nyssomyia intermedia (Lutz & Neiva, 1912) (8.53%), Nyssomyia whitmani (Antunes & Coutinho, 1939) (1.74%), and Migonemyia migonei (França, 1920) (0.45%). The presence of Leishmania DNA was assessed through quantitative PCR in female phlebotomine sand flies across 26 species. Although no positive samples were detected, the registration of autochthonous cases and the presence of proficient vectors establishes the essential conditions for ATL transmission and emphasizes the necessity for ongoing surveillance of its incidence within Montes Claros.