Incipient colonisation of Lutzomyia longipalpis in the city of Resistencia, province of Chaco, Argentina (2010-2012)

Lutzomyia longipalpis was recorded for the first time in Argentina in 2004, in the province of Formosa. In the following years, the vector spread to the south and west in the country and was recorded in the province of Chaco in 2010. From November 2010-May 2012, captures of Phlebotominae were made in the city of Resistencia and its surroundings, to monitor the spread and possible colonisation of Lu. longipalpis in the province of Chaco. In this monitoring, Lu. longipalpis was absent in urban sampling sites and its presence was restricted to Barrio de los Pescadores. This suggests that the incipient colonisation observed in 2010 was not followed by continuous installation of vector populations and expansion of their spatial distribution as in other urban centres of Argentina.

Identification of the natural breeding sites of sandflies (Diptera: Psychodidae: Phlebotominae), potential vectors of leishmaniasis, in the province of Chaco, Argentina

The aim of this work was to identify the natural breeding sites of sandflies in the province of Chaco, Argentina, for the first time. Preliminary studies were conducted in two different phytogeographic regions: dry Chaco (Parque Provincial Pampa del Indio), in January 2010, and humid Chaco (Resistencia, Margarita Belén and Colonia Benítez), from May-September 2010. A total of 127 samples were collected (Pampa del Indio: 15, Resistencia: 37, Margarita Belén: 36, Colonia Benítez: 39). A female of Migonemyia migonei was found in Pampa del Indio at the base of a bromeliad in the summer (January) and a pupal exuvium of a phlebotomine fly was found in Resistencia, in a place where dogs rested, in the winter (July). These findings highlighted these two sites as potential breeding sites. Because the existence of potential natural breeding sites for sandflies has been demonstrated in both forest and periurban areas, expanding the search efforts and characterising these sites will enable the development of specific study designs to gain insight into the spatial distribution of the risks posed by these vectors. The resulting information will serve as a basis for proposing and evaluating vector control measures.

Ecoepidemiología de la leishmaniasis cutánea en la Argentina / Eco-epidemiology of cutaneous leishmaniasis in Argentina

Se analizó e integró, desde un enfoque ecoepidemiológico, la literatura publicada sobre leishmaniasis cutánea en la Argentina a partir del primer brote epidémico registrado (1985-1987) y se incorporaron datos inéditos.Se discriminaron tres escalas espacio-temporales de análisis: 1) regional/decadal, 2) focos epidémicos/anual,3) sitio de captura/diaria-mensual. Escala regional: se observó una tendencia creciente de la incidencia, de la transmisión peridoméstica y de la frecuencia y distribución de los brotes (Este-Oeste), concurrente con la dispersión y dominancia de Lutzomyia neivai, vector de Leishmania braziliensis, en ambientes modificados. Escala foco epidémica: se caracterizaron tres escenarios de transmisión: 1) ciclo silvestre/transmisión silvestre, 2) ciclo silvestre/transmisión peridoméstica, 3) ciclo peridoméstico/transmisión peridoméstica rural-periurbana. Se adjudicaron los brotes registrados en Argentina a cada escenario. Escala sitio de captura: se concluyó que la distribución de Lu. neivai es microfocal, metapoblacional con recolonización del peridomicilio desde poblaciones fuente y que presenta una dinámica anual bimodal función de la temperatura y las precipitaciones. Se discuten los resultados de cada escala y categoría en el marco de posibles estrategias de vigilancia y control.