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.

The appearance of the vector of visceral leishmaniasis (VL) Lutzomyia longipalpis in the province of Formosa in 2004 was associated with urban epidemic risk for the first time in Argentina. During 2006, vectors, canine and human cases of VL were reported in the province of Misiones, and in summer 2008-2009, in the province of Corrientes. In Santiago del Estero province in 2008, cases of human and canine VL were associated with secondary vectors. Therefore, with the aim to know the current distribution of VL risk in the Chaco region, systematic captures of the vector were performed between January and April 2010 in 30 localities of Formosa and Chaco, and in the city of Reconquista, province of Santa Fe (224 traps/night). Lu. longipalpis was reported for the first time in the cities of Resistencia and Puerto Antequera (Chaco). Clorinda and Puerto Pilcomayo (Formosa) are the localities where the traps with more individuals were obtained, 158 and 241 Lu. longipalpis trap / site / night respectively. These results showed that the vector of urban epidemic VL is still spreading in Argentina, and already reached the province of Chaco. Sporadic cases reported in the Chaco region, transmitted by secondary vectors as Lu. migonei would also increase due to intensified surveillance, and the dispersion of the parasite associated with the transit of asymptomatic or symptomatic infected dogs.

El riesgo de leishmaniasis visceral (LV) urbana epidémica se registró por primera vez en la Argentina en el año 2004, por presencia del vector Lutzomyia longipalpis en la provincia de Formosa, la provincia de Misiones registra casos de LV humana, LV canina y vector en el año 2006, y la provincia de Corrientes en el verano 2008-2009. En la provincia de Santiago del Estero los casos de LV humana y LV canina en el año 2008 estuvieron asociados posiblemente a vectores secundarios. Por ello, para conocer la distribución del riesgo en la región del Chaco, entre enero y abril del 2010 se realizó la búsqueda sistemática del vector de LV en 30 localidades de las provincias de Formosa, Chaco y en la ciudad de Reconquista, Santa Fe (224 trampas/noche). Se comprobó la presencia de Lu. longipalpis, por primera vez, en las localidades de Resistencia y Puerto Antequera (Chaco). En Clorinda y Puerto Pilcomayo (Formosa) se obtuvieron las trampas con más ejemplares, 158 y 241 Lu. longipalpis trampa/sitio/noche respectivamente. Los resultados muestran que el vector de la LV urbana epidémica continúa dispersándose en el territorio argentino, habiendo ingresado a la provincia de Chaco. La notificación de casos esporádicos en la región chaqueña, transmitidos por vectores secundarios, como Lu. migonei, podría aumentar también debido a la vigilancia intensificada, y a la dispersión del parásito asociada al tránsito de perros infectados, sintomáticos o asintomáticos.