Background: An entomological study was conducted in the municipality of Oiapoque (lower Oyapock River Basin)
in the Brazilian side bordering French Guiana to gain information on the transmission pattern of American cutaneous
leishmaniasis (ACL) in that region, presumed to reflect the classical Amazonian/Guianan enzootic scenario.
Methods: Three ecologically isolated forested areas near urban environments were surveyed during the rainy and dry
seasons of 2015 and 2016, using a multi-trapping approach comprising ground-level and canopy light traps, black and
white colored cloth Shannon traps and manual aspiration on tree bases. Female phlebotomines were dissected to find
infections and isolate flagellates from Leishmania spp. The strains were characterized by restriction fragment length
polymorphism analysis and compared with those of local ACL cases and World Health Organization reference strains.
Results: Nyssomyia umbratilis, Trichopygomyia trichopyga and Evandromyia infraspinosa were the most frequently found
species. Findings on relative abundance, spatiotemporal vector/ACL congruence, natural infections and anthropophilic
insights strengthened the Guianan classical transmission of Leishmania (Viannia) guyanensis by Ny. umbratilis and
suggested further investigations for Ev. infraspinosa. Nyssomyia umbratilis showed an eclectic feeding habit, including
bird blood. Ecological data and literature reports also included Psychodopygus squamiventris maripaensis and
Bichromomyia flaviscutellata on the list of suspected vectors.
Conclusions: These findings contributed to understanding ACL ecoepidemiology in the Amazonian/Guianan scenario.
Local studies are required to better comprehend the Leishmania spp. enzootic mosaic in specific ecotopes.
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