Phlebotominae fauna in a recent deforested area with American tegumentary leishmaniasis transmission (Puerto Iguazú, Misiones, Argentina): seasonal distribution in domestic and peridomestic environments

Abstract

Phlebotominae sand flies have been involved as vectors of Leishmania. In Argentina, Nyssomyia neivai and Nyssomyia whitmani are involved as the main vectors of American Tegumentary Leishmaniasis (ATL). In the northeastern border of the country, an outbreak of ATL during 2004–2005 was associated with deforestation and subsequent settlement of farmers close to the edge of the forest. The aim of this work was to study the community composition of sand flies along time in farms located near primary and secondary forest in two environments: houses and pigsties. The association of abundance with temperature and precipitation was also evaluated for the most prevalent species. A total of 23,659 Phlebotominae belonging to the genera Nyssomyia, Migonemyia, Pintomyia, Evandromyia, Micropygomyia, Sciopemyia, Dampfomyia, Psathyromyia and Brumptomyia were captured. Ny. whitmani, which was the most abundant species, and Migonemyia migonei, which was the second most abundant species, were present throughout the year. Both species were positively associated with temperature, mostly up to 31–47 days, and with precipitation at 31 days before the sampling day. The abundance was higher in pigsties than in houses, but the time pattern was positively associated between both environments. These results confirm that Ny. whitmani is the dominant species in the study area and its presence throughout the year indicates a potential long period of ATL transmission. The presence of Mg. migonei as the second species in abundance is relevant, because it has been described as a secondary vector of the parasites of ATL and a putative vector of the agent of American Visceral Leishmaniasis. We discuss the role of the pigsty as the environment that attract more sandflies, taking into account the number of sand flies captured there, the distance from the home, and the association of sand fly abundance with each of the two environments.