Lutzomyia longipalpis in Clorinda, Formosa province, an area of potential visceral leishmaniasis transmission in Argentina

Abstract

Phlebotomine captures were performed with minilight traps CDC like overnight in Clorinda city, Puerto Pilcomayo, Laguna Blanca-Parque Pilcomayo (60 km west of Clorinda), "Km 1254" and "Km 1264" (60 and 50 km south of Clorinda respectivelly). Eleven sites were sampled between 7 and 11 June 2004, and 18 sites between 16-21 December 2004, at least two nights each site in both periods. The capture sites were selected within peridomestic habitats with close vegetation, animal dwellings and/or proximity to the border with Paraguay. The phlebotomine were cleared, mounted and identified as already published (Salomón et al. 2002) Seven individuals (4 males, 3 females) of Lu. longipalpis were captured in peridomestic pig pens of Puerto Pilcomayo ("Km 9" and "Km 11 1/2"). Besides, 3 males of Lu. longipalpis were collected in Clorinda peridomiciles (Libertad street 30 m from the river and Porteño Norte neighbourhood). One male of Lu. longipalpis was trapped in June, the remainder sand flies were caught in December. Despite the low densities found, this is the first report of a competent vector of VL in Argentina close to a current VL focus, and Formosa the second province ever reported with Lu. longipalpis in the country.Lu. cortelezzii (12 individuals), Lu. shannoni (1), and Lu. neivai (4) were also found in Clorinda and Puerto Pilcomayo capture sites, but no sand flies were collected in the surrounding southern or western villages. Lu. neivai is the prevalent species in tegumentary leishmaniasis foci of Formosa province (Salomón et al. 2002).In conclusion, there is a potential risk of VL transmission in Clorinda due to: i) the presence of Lu. longipalpis in Clorinda close to populated areas, ii) the reports of VL from the 'Great Asunción' in Paraguay, and iii) the fluent movement of individuals, bought and stray dogs along the border. Thus, an active surveillance system is required immediately in the area in order to improve the local capacities on detection and diagnose both human and canine leishmaniasis.

Visceral leishmaniasis in border areas: clustered distribution of phlebotomine sand flies in Clorinda, Argentina

“…longipalpis spatial distribution in ClorindaPuerto Pilcomayo in October 2007 clustered in northern and southern outskirt areas, almost in the same sites described in December 2004 when the species was first reported in the province of Formosa (Salomón & Orellano 2005), with no further spread to Laguna Blanca or Laguna Naineck. Similar to our results, high spatial heterogeneity of this vector has also been reported in the southern Brazilian focus of Campo Grande, where 90% of the sand flies captured in the urban environment were Lu.…”

“…In December 2004, Lu. longipalpis was found in Clorinda, Argentina, 40 km from Asunción, Paraguay (Salomón & Orellano 2005). During 2006, the first autochthonous focus of L. i. chagasi transmission associated with human and canine VL and Lu.…”

Lutzomyia longipalpis behavior and control at an urban visceral leishmaniasis focus in Argentina

“…Phlebotominae sand flies were captured in the city of Posadas using CDC battery powered mini light traps overnight 35 The study of Phlebotomine distribution by hour was performed in the backyard of the first reported case of human VL (S27º 23' 00", W55º 54' 19") 32 . The CDC trap was located in a three-wall storeroom over a dog during five consecutive nights from 2/12/2007 to 16/12/2007.…”

“…More recently in 2005, Lu. longipalpis was found in Clorinda City on the border with Paraguay, with no VL human cases 32 .…”

Spatial Distribution of Phlebotominae in Puerto Iguazu-Misiones, Argentina-Brazil-Paraguay Border Area

“…Due to the recording of LV cases in Paraguay and Brazil, a system of vector vigilance was organized on the border area. This resulted in findings of the VL agent vector in Clorinda, Formosa in 2004 17 .…”