Phlebotomine Fauna (Diptera: Psychodidae) and Putative Vectors of Leishmaniases in Impacted Area by Hydroelectric Plant, State of Tocantins, Brazil

Abstract

BackgroundAlthough leishmaniases are regarded as serious public health issues in the State of Tocantins, as consequence of the impact of environmental changes, small advances in taxonomic and ecological studies of Phlebotominae fauna are taking place in this state. The present study aimed to improve the knowledge about the sand flies, as well as about the aspects of the bioecology of leishmaniases vectors from Porto Nacional, a city that was directly impacted by the construction of Luís Eduardo Magalhães Hydroelectric Plant (HEP – Lajeado).Methodology/Principal FindingsSand flies were collected monthly using CDC light traps and Shannon traps for a period of 40 consecutive months, at different monitoring stations, where 7162 specimens were collected and 48 species were detected. Among the species found, 22 are first records in the state and seven are considered important vectors of leishmaniases. Lutzomyia longipalpis, the vector of American Visceral Leishmaniasis (AVL) showed higher frequency in urban compared to rural areas, and Nyssomyia whitmani, the vector of American Cutaneous Leishmaniasis (ACL), predominated in rural areas. The frequency and habits of sand fly vectors are discussed considering environmental characteristics and climatic factors.Conclusions/SignificanceThe construction of dams requires a great amount of labor, therefore attracting people from elsewhere. Increased migration, without adequate structure, leads to bad living conditions in new and unplanned settlements. It also leads to deforestation associated with environmental impacts, which can facilitate the spread of leishmaniases.This study discusses the importance of Lu. longipalpis and Ny. whitmani on the transmission cycles of leishmaniases in Porto Nacional and the record of Bi. flaviscutellata in periurban area of the city.

Phlebotominae sand flies (Diptera: Psychodidae): potential vectors of American cutaneous leishmaniasis agents in the area associated with the Santo Antônio Hydroelectric System in Western Amazonian Brazil

“…The Chao/ Jackknife indices calculated in the present study indicated that the sampling effort was suffi cient to completely estimate the species richness in the studied region. Several recent studies have described a high level of biodiversity of sand fl ies (>50 species registered in some of environments) in areas associated with hydroelectric systems in Brazil (21) (22) (23) . The present study is the fi rst to provide a longitudinal evaluation of sand fl y populations before and after the fi lling of a dam.…”

Epidemiological aspects of visceral leishmaniasis in Jaciara, Mato Grosso, Brazil, 2003 to 2012

“…In Três Lagoas, 14 species were recorded between 2000 and 2006, totaling 4,277 specimens collected, with L. longipalpis corresponding to 87% (OLIVEIRA et al, 2010). Unlike these regions, faunal studies on these insects in Tocantins showed high species richness, with 48 species described in the municipality of Porto Nacional between 2004 and 2007, and revealing predominance of L. longipalpis, L. whitmani and L. sordellii (VILELA et al, 2011). In the Taquaruçu district, six months of research resulted in 767 sandfly specimens from 32 different species (MACHADO et al, 2012).…”

Ecoepidemiology of American Visceral Leishmaniasis in Tocantins State, Brazil: Factors Associated with the Occurrence and Spreading of the Vector Lutzomyia (Lutzomyia) longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae)

“…Its presence in Tocantins is unlikely, then. The presence of L. (L.) longipalpis was assumed only in municipalities where the information was missing, so given the wide distribution of L. longipalpis in Brazil [12] and, more specifically, in Tocantins State [29][30][31][32][33][34][35][36][37], the chances of its capture in a new sand fly survey are high.…”

“…From the scarce bibliographic records that were found (9), the vector was recorded in only 22 municipalities of Tocantins [29][30][31][32][33][34][35][36][37]. In contrast, there are records of human cases in 124 municipalities, which demonstrate the lack of entomological studies in the state ( Figure 5).…”

“…Considering the occurrence of L. (L.) longipalpis in all municipalities where there are records of autochthonous human cases of AVL, in addition to the information from the literature [29][30][31][32][33][34][35][36][37], it is suggested that the vector is present in all classes of land use ( Figure 5, Table 1). …”