Ecology of phlebotomine sand flies in an area of leishmaniasis occurrence in the Xakriabá Indigenous Reserve, Minas Gerais, Brazil

Abstract

Introduction: Leishmaniasis is a complex vector-borne infectious diseases caused by protozoan parasites in the genus Leishmania and spread by hematophagous phlebotomine sand flies (Diptera: Psychodidae, Phlebotominae). The aim of this study was to investigate the phlebotomine fauna, endophily and exophily of the species found, and possible influence of climatic factors on their populations. Methods: The study was conducted in the Xakriabá Indigenous Reserve (XIR) in the municipality of São João das Missões in northern Minas Gerais state, Brazil. Insects were collected over three consecutive nights in the last week of each month for 12 months from July 2015 to May 2016 from four houses in four different villages. Two traps were set up in each house: one in the intra-domicile and another in the peri-domicile. Results: A total of 2,012 phlebotomine sand fly specimens representing 23 species and belonging to 10 different genera were captured and identified. Among the studied villages, Riacho do Brejo showed the highest density and diversity of phlebotomine sand flies. The species Lutzomyia longipalpis (80.3%) and Nyssomyia intermedia (7.3%), which are major vectors of visceral and cutaneous leishmaniasis, respectively, had the highest population densities, both in the intra-and peri-domicile. No correlation was observed between climatic factors and the density of phlebotomine sand flies. Conclusions: The results of the present study may contribute to a better understanding and targeting of the measures for preventing and controlling leishmaniasis by the authorities responsible for indigenous health.

Lutzomyia longipalpis, Gone with the Wind and Other Variables

“…The agreed preconditions for selecting capture sites, labeled as worse scenarios, best scenarios, or critical sites, act as a quasi-controlled natural experiment design and so could minimize certain associations. This statement has already been discussed for chickens and animal dwellings, but is also valid for organic matter in soil, trees, and relative humidity vegetation (Costa et al 2019). Further, when these factors, taken as qualitative variables with dichotomous or trichotomous values, were added to characterize "receptivity levels" for Lu.…”