Study of phlebotomines in two wild areas of northeastern Argentina and the potential association with howler monkeys (Alouatta caraya)

MARTINEZ, MARIELA; SANTINI, MARIA S; UTGES, MARIA E; KOWALEWSKI, M MARTIN; SALOMON, DANIEL

Puerto Iguazu

Simposio; International Symposium of Phlebotomine Sandflies; 2014

Instituto de Medicina Tropical-Redila

The interaction among the insect vector, the parasite, and the animal reservoir determines the dynamic of infection of vector borne diseases. The animal reservoirs of each Leishmania species vary according to the environment and geographic location, and may include both domestic and wild animal hosts. Sandflies are found in different microenvironments of heterogeneous forest ecosystems. The goal of this study is to describe and compare the Phlebotominae species composition among two forest strata in Alouatta caraya sleeping trees and two wild areas inhabited by this primate. The study sites were Isla Brasilera (IB) Chaco (27°26 S, 59°40 W) and San Cayetano (SC) Corrientes (30°47 S, 55°40 W). The former is a small island in the Paraná River characterized by flooded forest with little to no human contact, and the latter corresponds to the surroundings of a rural locality exhibiting forest patches surrounded by grasslands. In both sites A. caraya (black and gold howler monkey) is the most important arboreal mammal in terms of biomass. Sandflies were captured with light traps hung close to monkey sleeping trees at 1.5 m (low) and 6-8 m (canopy) above the ground and set on for two consecutive nights. A total of 964 sandflies were collected in IB (n=7 sleeping trees) belonging to 6 species: Nyssomyia neivai (84.6%), Brumptomyia sp. (12.6%), Migonemyia migonei (2%), Psathyromyia shannoni (0.6%), Ny. whitmani (0.1%), and Evandromyia cortelezii-sallesi (0.1%). A total of 1125 sandflies were collected in SC (n=9) belonging to 7 species: Ny. neivai (50%), Brumptomyia sp. (25.5%), Mg. migonei (22.8%), Ny. whitmani (0.9%), Ps. shannoni (0.4%), Ev. cortelezii-sallesi (0.3%), and Pintomyia pessoai (0.1%). Ny neivai was the most abundant species in both sites. The comparison of Ny. neivai abundances among sites and heights by nested ANOVA showed significantly higher abundances in the lower stratum (F1,12=6.26; p=0.028), but no significant effect of site factor (F1,12=0.03; p=0.872) or interaction between site and stratum (F1,12=0.31; p=0.588). The presence of potential vectors of Leishmania spp. in the canopy of sleeping trees, though less abundant than in the lower stratum, suggests that A. caraya might serve as wild mammal blood source, and therefore, as an amplifier of the vector population or even a potential reservoir host of leishmanias in these wild areas.