Ecology and molecular analysis of sand flies in Bambuí, Minas Gerais, Brazil: Implications for leishmaniasis surveillance.

Leishmaniasis stands out as a public health problem in the state of Minas Gerais, Brazil, especially in the Midwest region. However, the entomological aspects in several municipalities remain unknown. Therefore, this study aimed to investigate the sand fly fauna in Bambuí, encompassing ecological dynamics and molecular detection of Leishmania. Monthly collections were conducted using CDC light traps from September 2018 to August 2020 across 16 selected points with urban and rural characteristics, chosen based on the coverage area of the Municipal Health Department and the occurrence of canine and human visceral leishmaniasis (VL) cases. Ecological indices of the sand fly population (Chao1, Shannon, Simpson and Pielou) were assessed, and sand fly abundance was correlated to climatic variables (humidity, temperature and rainfall). A total of 8838 specimens representing 17 species within nine genera were collected (estimated species richness by Chao 1 estimator = 17; SE ± 1.8). Predominantly, Lutzomyia longipalpis, Nyssomyia whitmani and Evandromyia cortelezzii constituted approximately 98% of all captured sand flies. While species richness and diversity displayed variations throughout the study, a positive correlation emerged between temperature (p < 0.0001; r = 0.7767), monthly rainfall (p < 0.0001; r = 0.7810) and sand fly abundance. Molecular analysis revealed Leishmania DNA in 2.05% of female sand flies, with the presence of Leishmania infantum in Lu. longipalpis and both Le. infantum and Leishmania braziliensis in Ev. cortelezzii. The entomological data, coupled with the occurrence of autochthonous cases of canine visceral leishmaniasis, offer valuable insights for evidence-based strategies to prevent leishmaniasis in Bambuí.

Carvalho GML ，Dutra-Rêgo F ，Andrade-Filho JD 《-》

Entomological Studies in Itaúna, Brazil, an Area With Visceral Leishmaniasis Transmission: Fauna Survey, Natural Leishmania Infection, and Molecular Characterization of the Species Circulating in Phlebotomine Sand Flies (Diptera: Psychodidae).

Among neglected tropical diseases, visceral leishmaniasis (VL) shows great relevance in global terms and is a serious public health concern due to the possibility of severe and lethal forms in humans. In this study, we evaluate entomological factors such as diversity and abundance of phlebotomine sand flies (Diptera:Psychodidae) and the Leishmania species circulating in these species in possible association with VL transmission in the Brazilian town Itaúna. The entomological collections were performed during three consecutive nights, always in the third week of each month, within a period of 12 mo. A total of 1,786 sand fly specimens were collected, from which 20% were collected inside houses. The influence of three local climatic variables (temperature, rainfall, relative humidity) on the population sizes of these insects was evaluated. Temperature was the most influential factor, with a significant positive correlation with the local population size of phlebotomine sand flies collected per month. Lutzomyia longipalpis (Lutz & Neiva, 1912) was the predominant species in the study area. Leishmania DNA was detected in nine out of 133 pools of sand fly females, using nested/PCR, which resulted in a minimal natural infection rate of 2.91%. DNA from Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatida), was detected in Evandromyia cortelezzii (Bréthes, 1923), Ev. evandroi (Costa, Lima & Antunes, 1936), Ev. lenti (Mangabeira, 1938), and Ev. termitophila (Martins, Falcão & Silva, 1964), besides Lu. longipalpis. Our study indicates favorable conditions for VL spreading in Itaúna due to the presence of Lu. longipalpis and Le. infantum-infected phlebotomine sand flies.

Lopes JV ，Michalsky EM ，Pereira NCL ，de Paula AJV ，Lara-Silva FO ，Silva-Lana R ，Fortes-Dias CL ，Pinheiro LC ，Dias ES ... -  《-》

Diversity, Leishmania detection, and blood meal sources of sand flies from Iguatama, Minas Gerais, Brazil.

This study investigated the sand fly fauna of the municipality Iguatama, in the Midwest Region of Minas Gerais state, Brazil, including Leishmania infection rates and blood meal sources. Sand flies were collected during four periods over the course of a single year, encompassing both dry and rainy seasons, using CDC light traps placed in peridomiciles where dogs were seropositive for visceral leishmaniasis (VL). A total of 762 sand fly specimens, representing 12 species across seven genera, were collected. Lutzomyia longipalpis was the most abundant species, comprising 57.6% of the collected specimens, followed by Nyssomyia neivai (19.6%) and Nyssomyia whitmani (10.5%). Species richness and diversity varied among collection periods, with the highest diversity observed in January 2019. Molecular analysis detected Leishmania DNA in 12.5% of the sand fly specimens, with Le. infantum being the predominant species. Blood meal analysis revealed feeding on multiple vertebrate species, including humans, rats, dogs, and chickens. The presence of Leishmania DNA in sand flies, and the identification of human blood meals, highlight the potential role of these species in VL transmission. These findings underscore the importance of continued surveillance and control measures to prevent the spread of VL and reduce transmission risk in the region.

Dutra-Rêgo F ，Binder C ，Capucci DC ，Vaz TP ，Andrade Filho JD ，Fontes G ，Gontijo CMF ... -  《PLoS One》

Ecoepidemiological aspects of visceral leishmaniasis in an endemic area in the Steel Valley in Brazil: An ecological approach with spatial analysis.

Lana RS ，Michalsky ÉM ，Lopes LO ，Lara-Silva FO ，Nascimento JL ，Pinheiro LC ，França-Silva JC ，Mendes TSC ，Fortes-Dias CL ，Dias ES ... -  《PLoS One》

Diversity of phlebotomine sand flies and molecular detection of trypanosomatids in Brumadinho, Minas Gerais, Brazil.

Tanure A ，Rêgo FD ，Tonelli GB ，Campos AM ，Shimabukuro PHF ，Gontijo CMF ，Paz GF ，Andrade-Filho JD ... -  《PLoS One》