Diagnosis of Canine Visceral Leishmaniasis by Flow Cytometry Serology using the rMELEISH Multiepitope Antigen Coupled in a Functional Bead

Background: Visceral leishmaniasis (VL) is a zoonotic disease, with dogs being the main reservoir of the Leishmania infantum parasite. Objective: To develop a new flow cytometry test to diagnosis canine VL (CVL) diagnosis. Methods: The current study addresses a new flow cytometry test using beads coupled to the multiepitope antigen rMELEISH. Results: In the study set of samples a sensitivity (87.1%) and specificity (89.9%) was observed. Considering the dogs’ clinical status, 20/20 (100.0%) of the symptomatic sera tested positive, while 19/22 (86.4%) of the oligosymptomatic and 16/20 (80.0%) of asymptomatic were positive. In the non-infected control, all samples (0/30) tested as negative. In the cross-reaction control, the test was more efficient in dogs infected with L. braziliensis (2/10) and Trypanosoma cruzi (0/10), than those with Babesia canis (4/10) and Ehrlichia canis (4/10). Dogs immunized with different vaccines (Leishmune, Leish-Tec^®, or LBSap) did not present serological reactivity. Conclusion: The flow cytometry serology through coupling the antigen rMELEISH in functional beads showed high accuracy in diagnosing CVL.