Assessing the vectorial capacity of Lutzomia longipalpis sand fly as possible vector for crithidia-like parasites

Abstract

Human Visceral Leishmaniasis (VL) is a neglected disease caused by the two-host lifecycle protozoa parasite, Leishmania infantum, the parasite transmitted by sand fly bites of an infected female. VL can be lethal if untreated or treatments fail. VL is endemic in Brazil, showing a great focus on Northeastern region, although recently it has spread across several regions of the country. Reports of leishmaniasis cases with co-infection with monoxenous trypanosomatid have been increasing annually. However, there is no study involving the experimental transmission of these monoxenous parasites. Previous genomic analysis demonstrated that clinical isolates from VL patients admitted at the Federal University Hospital in Sergipe, Brazil, don't belong to any Leishmania species and are closely related to the non-pathogenic Leishmaniinae parasite from genus Crithidia (Young Investigator Grant, JP-FAPESP, entitled "Visceral Leishmaniasis: genomics approaches for integrated molecular analysis of host and parasite"). We referred to this parasite as Crithidia-like. Here, our aim is to evaluate the capacity of Lutzomyia longipalpis sand flies to acquire, maintain, and transmit Crithidia-like parasites. For this purpose, we will work in collaboration with Dr. Jesus G. Valenzuela, Chief of Vector Molecular Biology Section of National Institute of Allergy, and Infectious Diseases/National Institute of Health. The clinical isolates were obtained from atypical cases of VL (one fatal), in which the parasite strains were isolated from skin lesions and bone marrow aspirates. In this context, experimental infection analyses of the Lu. longipalpis infected with Crithidia-like parasites will guide us to understand the capacity of transmission of this new emerging parasite in Brazil. (AU)