Vertical and horizontal distribution of sand flies in an area with a history of transmission of Tegumentary Leishmaniasis in Chaco, Argentina.

JUAN RAMÓN ROSA; MATÍAS ARIEL PARRAS; ENRIQUE ALEJANDRO SZELAG; OSCAR DANIEL SALOMÓN

Puerto Iguazú

Simposio; 8th International Symposium on Phlebotomine Sandflies; 2014

Instituto Nacional de Medicina Tropical - Ministerio de salud de la Nación

During the active search for human cases of cutaneous leishmaniasis in a dry and wet transitional chacoan bio-region, an inhabited dwelling from a rural area (26º20´22"S, 60º15´44") of Tres Isletas as worst epidemiological scenario was selected. Five CDC-type light traps/month/night/12hs(19:00 to 7:00 pm) were used in domicile, peridomicile (goats pens and piggery) and forest 110m from domicile where anthropic activities were evident. Also in forest 2 traps were installed in a tree, near the ground level at 1.5m and canopy level 10m. From December to December 2010-2012 a total 1179 Phlebotominae were captured: Migonemyia migonei (82%), Evandromyia cortelezzii (2.4%) only males, Ev. sallesi (5%) only males, cortelezzii complex females (9%): (including Ev. cortelezzii and Ev. sallesi of similar morphology), Nyssomyia neivai (0.3%), Psathyromyia shannoni (0.1%) and Brumptomyia brumpti (1.2%). Mg. migonei predominated on December 2011 (n=309) with average temperature and relative humidity of 31ºC and 32%, respectively. Only in summer 2010 (November/December) all species were recorded in peridomicile and domicile with the greatest abundance in the first (n=467) and the lowest in the second one (n=81) predominating Mg. migonei in both (n=405; n=71, respectively). In vertical strata, all species were recorded in ground level. In 2010, the highest abundance was in canopy (n=289) in autumn (March/April), and the lowest in ground level (n=245) in summer (November/December). Mg. migonei was the predominant followed by Ev. cortelezzii, Ev. sallesi and cortelezzii complex females. The least were Pa. shannoni only in ground level and Br. brumpti in ground and canopy levels. In all seasons 2010 there was Phlebotominae in both strata, with highest abundance in summer (n=422) 28°C and 45% and lowest in winter (n=20), 12°C and 55%. In 2011, the highest was in spring (n=166) 24°C and 66% and the lowest in summer (n=74) 27°C and 58%. Species suspected as vectors of leishmaniasis in this region were recorded in both strata, in all seasons. This behavior was probably due to the meteorological and microclimate conditions, soil type and vegetation, limited by physiological factors such as changes in the food habits favored by anthropic activities. The need for further large-scale studies to contribute to the knowledge of bionomics and environmental change in an epidemiological context are showed. Financial support: Roemmers Argentina Foundations.