The emergence and spread of leishmaniases in the borders of Argentina, Brazil, Paraguay and Uruguay.

SALOMÓN OD; QUINTANA MG; SANTINI MS; GONZÁLEZ-BRITEZ N; MARTÍNEZ N; ROJAS DE ARIAS A; THOMAZ-SOCCOL V; GONÇALVES A; BISETTO JA, ; WILLAT G; CALEGARI L; BASMADJIAN Y; YADON ZE; IDRC PROJECT #107577 TEAM

Reims

Simposio; IX International Symposium on Phlebotominae Sandflies; 2016

Since 2014 in the border region of Argentina (Ar), Brazil (Br) and Paraguay (Py), a multi-country project has been carried out toidentify the main biological, environmental and social drivers associated with the risk of transmission of leishmaniases, within thetheoretical frame of Eco-Health. Uruguay (Uy) joined the project since the emergence of cVL in 2015. The entomologicalcomponent of the project involves three-night sampling with mini light traps in urban-periurban domestic units, rural-forestand rural-periurban transects by; (a) transverse survey on grids of 400 · 400 m (censal or stratified according to the size ofthe locality), (b) longitudinal, seasonal/monthly surveys (10% of the original sites). More than 500 sites were sampled amongthe four countries. The main results so far have shown: (a) the dominance of Lutzomyia longipalpis (VL vector) in the urbanstratum, both indoors and in peridomestic environments. It is more frequent/abundant in the warmer seasons and places with atendency to spread to the rural non-sylvatic areas. The dominance of Nyssomyia whitmani (CL vector) in the sylvatic-ruralstratum, and in ??green patches?? within urban areas, persistent in colder seasons and places. This spatial segregation was associated with variables that could allow the modelling of the spatial distribution of vectors in time and space at different scales.(b) The evidence-based delimitation of an area for environmental interventions at macrohabitat scale of 400 · 400 m. (c) Thegenotipification of Leishmania infantum and L. braziliensis as the main parasites circulating in the region, infecting indoor andoutdoor sand flies. In order to avoid averaging very diverse results the actual figures of relative abundance will be shown in tables.However, related to the current spread Lu. longipalpis we could distinguish different scenarios: (a) the broad urban distribution ofthe vector, with cVL prevalence rates of 22?26%, and increasing prevalence during the longitudinal survey: Foz do Iguaçu-Br andPuerto Iguazú-Ar. (b) incipient colonization by Lu. longipalpis and 2?4% of cVL: Santa Terezinha de Itaipu-Br and Puerto Libertad-Ar. (c) vectors and cVL restricted to small foci: Presidente Franco-Py (rural-urban) and Ciudad del Este-Py (urban) with 2%cVL prevalence, and three foci in Salto-Uy with cVL rates from 1 to 12% in the main focus. (d) Vectors of CL (Ny. whitmani and alower proportion Ny. neivai) without Lu. longipalpis, and cVL only from imported cases in transects. (e) In Paysandú-Uy, no vectorswere found, so the southernmost border up to now of Lu. longipalpis-VL spread is Salto-Uy. The analysis of the entomologicalcomponent and the integration with the results from other disciplinary components are currently in progress.Financial support: IDRC-Canada Project #107577, Ministry of Health of Argentina, Brazil, Paraguay and Uruguay;PAHO.