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

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

Toledo

Congreso; 6th World Congress on Leishmaniasis; 2017

Instituto de Salud Carlos III - Drugs for Neglective Diseases inicitaive

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 the presence of Nyssomyia whitmani (Nw)asthemainvectorrelatedtounmodifiedenvironmentsanditsecotones.Regardingtovisceralleishmaniasis(VL)urbanreportsstartedin2010withLutzomyialongipalpis (Ll)as the main vector. Methods: We divided the urban and periurban environments of both cities into a grid of 400m2, with 55/15 samples sites respectively. In rural areas and natural forests we set12/13samplesites. The selection criterion for all sites was the worsts scenario. In each site, REDILA traps were set for three consecutive nights, and a total of 48 meso and microscale environmental characteristics surveyed simultaneously. The proportion covered by six landcover classes were estimated for different surface areas (between 0.27 and 20.25 hectares) around each sampled site. The best area was selected comparing the deviance explained by adjusted Generalized Linear Models. To evaluate the possible determinants for each vector we developed a zero-inflated negative binomial regression model. We analyzed females for detection of Leishmania infantum DNA, products we repurified and sequenced for identity analysis with BLASTm. 3 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(microscale)and Normalized Difference Water Index (mesoscale), 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). Analysis of Nw is in progress. Leshmaniainfantum DNAwasdetectedin7/369,5Ll,1Nwand1Micropygomyiaquinquefer (first detection).4 Conclusions: Lutzomyia longipalpis has urban distribution related to urbanization indicators, food presence and water bodies in the closeness. Nyssomyia whitmani (preliminary) has a preference for areas with higher vegetation presence, in mixed landscapes(periurban, rural, natural areas). The selection of the better scale will allow designing appropriate control strategies according to each species.Financial Support IDRC-CanadaProject#107577-001, MinistryofHealthofArgentina