Evaluating the Adaptation Process of Sandfly Fauna to Anthropized Environments in a Leishmaniasis Transmission Area in the Brazilian Amazon

Abstract

Phlebotomines (Diptera: Psychodidae) are vectors of several etiological agents of human and animal diseases, including protozoans of the gender Leishmania. Precarious socioeconomic conditions and uncontrolled population growth directly influence the transmission risk of parasites and the urbanization of vector species, previously restricted to wild environments. The Marajó Archipelago is considered a high incidence area of leishmaniasis in the Brazilian Amazon. However, it is poorly studied. The aim of this study was to assess the adaptation processes of phlebotomine species to anthropized environments in this region. For this purpose, the phlebotomine fauna was compared between three municipalities of the Marajó Archipelago: Anajás, Portel, and São Sebastião da Boa Vista. To survey the phlebotomine fauna, CDC (Center for Disease Control) light traps were installed in the wild areas and in the intra and peridomiciliary areas of rural and urban environments. The environments studied presented a diversified phlebotomine fauna, with higher richness in the wild environment (15 species), followed by the rural (seven species), and finally, the urban environment (three species). A migration of wild fauna to the adjacent anthropized areas (rural environment) and to urban areas was observed, evidencing the adaptation process of this vector to anthropized environments in the studied region. Thus, our study evidenced that the disorganized human occupation and utilization of the landscape might cause the invasion of urban areas by wild populations of phlebotomines, in this way enabling the settlement of urban leishmaniasis transmission cycles.

Distribution of the assemblage of phlebotomine sandflies (Diptera: Psychodidae) along an environmental gradient

“…On WE1, we found the highest proportion of males, compared to females. The higher proportion of males in the population have been previously reported and this corroborates the results obtained in studies involving sampling of phlebotomines using light trap (Dye et al 1991, Barata et al 2004, Rosario et al 2017. For example, male sand flies are attracted to plants as a source of sugar meals.…”

Ecological aspects of Phlebotomines (Diptera: Psychodidae) and the transmission of American cutaneous leishmaniasis agents in an Amazonian/ Guianan bordering area

“…Despite high overall species diversity, numerical domination (74.8%) of only three species was expected. Studies on forested environments have shown a phlebotomine fauna generally composed of a few dominant species and many species with few specimens [ 46 , 47 ].…”

Palaeoclimatic models - predicted changes in the potential Neogene distribution patterns of Phlebotomus similis and Phlebotomus sergenti (Insecta: Diptera: Psychodidae)

“…In certain cases, sandflies could adapt quickly to new environments. Rosário et al (2017) documented that several New World sandfly species were adapted to the urbanised regions of Brazil in the last few decades. However, it should be noted that warmer, nutrient-rich and predator-poor habitats provided by cities are favoured by sandfly species.…”