Abstract INTRODUCTION: Malaria and leishmaniases are transmitted by vectors during blood-feeding. Vector-infected animals develop antibodies against the vector’s saliva. This study evaluated IgY antibody detection in the chicken eggs exposed to bites from Migonemyia migonei, Lutzomyia longipalpis and Anopheles aquasalis. METHODS: We used ELISA to quantify the antibody levels in the sera and exposed chicken eggs. RESULTS: High IgY levels were observed following immunization; furthermore, higher reactivity was observed in the eggs and species-specific immune response was observed post final immunization. CONCLUSIONS: Chicken eggs can be used as sentinels to surveil vector saliva antibodies.

BACKGROUND Lutzomyia umbratilis, the vector for Leishmania guyanensis in northern South America, has been found naturally infected with L. guyanensis only in areas north of the Negro and Amazon rivers. While populations of this sand fly species are also found in areas south of these rivers, these populations have never been reported to be infected and/or transmitting L. guyanensis. However, no studies on the corresponding host-parasite interactions are available. OBJECTIVES This study evaluated the interaction between Lu. guyanensis promastigotes and field-collected Lu. umbratilis sand flies from Rio Preto da Eva and Manacapuru, which are located to the north and south, respectively, of the Negro River. METHODS Procyclic and metacyclic attachment was quantified using an in vitro system. FINDINGS Low attachment of parasites to the midguts of insects collected from Manacapuru was detected. Conversely, greater binding of metacyclic parasites was observed in the midguts of insects collected from Rio Preto da Eva, and this attachment was more pronounced than that observed for procyclics (p < 0.03). MAIN CONCLUSIONS The Lu. umbratilis population from an area south of the Negro River has lower in vitro interaction with L. guyanensis. The higher attachment of L. guyanensis to midguts of insects from Rio Preto da Eva may suggest better vector competence. These findings are in accordance with previously reported epidemiological information of American cutaneous leishmaniasis (ACL) transmission in the Amazon.

Phlebotomine sand flies are responsible for the transmission of the etiological agents of several diseases, including protozoan parasites that cause leishmaniases. In the Lutzomyia França genus, the females of some species are morphologically similar, and the morphological characters normally used to identify them are unreliable. The aim of this study was to distinguish between females of cryptic Lutzomyia França species from the subgenus Psathyromyia Barretto by analyzing the armature in the genital atrium (AGA). The species studied were Lutzomyia dendrophyla Mangabeira, L. scaffi Damasceno & Arouck and L. shannoni sensulato Dyar. Lab-reared females were dissected to isolate the genital atrium and spermathecae. The AGA of each species was then photographed, and the arrangement of spines described. We conclude that the AGA can be a useful tool for distinguishing between female cryptic species of the subgenus Psathyromyia.