The diversity of sandflies (Psychodidae: Phlebotominae) and the presence of Leishmania spp. DNA in potential vectors of the Mbaracayú Forest Biosphere Reserve, Canindeyú, Paraguay: New records and findings

Abstract

Leishmaniasis is a zoonotic disease where parasites of the genus Leishmania are transmitted among hosts by sandfly vectors of the subfamily Phlebotominae. In Paraguay, studies on sandfly biodiversity are limited, even though the disease is present in its tegumentary and visceral forms. This pioneering ecoepidemiological study analyzes the diversity, abundance, and detection of Leishmania spp. DNA in sandflies from primary, secondary, and degraded forest habitats within the Mbaracayú Forest Biosphere Reserve. Over a year of sampling, 954 sandflies were captured, comprising 599 females and 355 males, belonging to 12 species, 10 of which are reported for the first time in Canindeyú. The species with the highest positivity for Leishmania spp. DNA were the Evandromyia cortelezzii complex (20.3%), Pintomyia monticola (18.8%), Brumptomyia brumpti (17.4%), Brumptomyia avellari (15.9%), and Psathyromyia lanei (11.6%). In contrast, Evandromyia evandroi, Micropygomyia quinquefer, Nyssomyia neivai, and Migonemyia migonei displayed rates of 4.3% or lower, while Psathyromyia shannoni complex, Brumptomyia guimaraesi, and Evandromyia termitophila were negative. The identified Leishmania species were L. amazonensis (65.2%) and L. infantum (34.8%). Additionally, dogs and their ectoparasites from an indigenous community were analyzed, detecting L. amazonensis DNA in 18 flea groups (54.5%) and one tick (16.7%). However, all dogs tested negative for the Rk39 test. This study highlights the risk of leishmaniasis transmission in forested and degraded ecosystems, which could have significant public health consequences, calling for deeper analyses to assess associated risks.