Micro and meso scale environmental determinants of Lutzomyia longipalpis and Nyssomyia whitmani abundance, main vectors of visceral and cutaneous leishmaniasis in Puerto Iguazú, Agentina

QUINTANA, M.G.; SANTINI M.S.; CAVIA, R.; MARTÍNEZ, M.; FERNANDEZ, M.S.; LIOTTA, D.J.; GIULIANI, M.; MOYA, S.L.; SALOMÓN, O.D.

Congreso; 6th World Congress on Leishmaniasis; 2017

Background: The study area includes the localities of Puerto Iguazú and Puerto Libertad, northeast Argentina. The area reported outbreaks of cutaneous leishmaniasis (CL) since the ´90s, with presence of Nyssomyia whitmani (Nw) as the main vector related to unmodified environments and its ecotones. Regarding to visceral leishmaniasis (VL) urban reports started in 2010 with Lutzomyia longipalpis (Ll) as the main vector. Methods: We divided the urban and periurban environments of both cities into a grid of 400 m2, with 55/15 samples sites respectively. In rural areas and natural forests we setted 12/13 sample sites. The selection criterion for all sites was the ?worst scenario?. In each site, REDILA traps were set for three consecutive nights. A total of 48 meso and microscale environmental characteristics were survey simultaneusly. Proportions covered by six landcover classes were estimated for different surface areas (between 0.27 and 20.25 hectares) arround each sampled site. The best extend area was selected compared the deviance explained adjusted Generalized Linear Models. We developed a zero-inflated negative binomial regression model to evaluate the posible determinants of each vector. We analyzed females phlebotomines individually for detection of Leishmania infantum DNA, products were purified and sequenced for identity analysis with BLASTm. Results: Ll abundance was better explained by the land cover characteristics of the area of 20.25ha, and for Nw the areas of 1.05ha and 20.25ha. The significant variables for the ?zero-inflated? component of Ll were the presence of chicks (micro scale) and Normalized Difference Water Index (meso scale), while the abundance of Ll was related to A) Mesoscale: drinking water network, garbage collection, sewer and B) Microscale: availability of differents blood sources (presence of hens, dogs or both). Analisys for Nw are in progress. Leshmania infantum DNA was detected, 5 Ll, 1 Nw and 1 Micropygomyia quinquefer (first detection in Argentina).Conclusions: Lutzomyia longipalpis has urban distribution related to greater urbanization, food presence and water bodies in the closeness. Nyssomyia whitmani (preliminary) has preference for areas with higher vegetation presence, in mixed landscapes (periurban, rural, natural areas). The selection of the better scale will allow to design appropriate control strategies according to each species. Financial Support IDRC-Canada Project #107577-001, Ministry of Health of Argentina