64. Development of a sensitive and specific Leishmania Lineblot, able to differentiate between vaccination and disease Andreas Latz1 , Daniela Heinz1 , Alba Fresco2 , Cristina Aira2 , Rouzbeh Mahdavi3 , Ulrich Steinhoff3 1) NovaTec Immundiagnostica GmbH, Veterinary Diagnostic Department, Dietzenbach, Germany 2) Eurofins Technologies Ingenasa; Lateral Flow Department, Madrid, Spain 3) Philipps-University Marburg; Institute for Medical Microbiology and Hospital Hygiene, Marbugr, Germany Corresponding author: Andreas.Latz@goldstandarddiagnostics.eu
Introduction: Canine leishmaniasis is a zoonotic disease by the protozoan parasite Leishmania transmitted by the bite of an infected phlebotomine sandfly. Leishmania infantum is the most common and important cause of canine leishmaniasis worldwide. Other Leishmania spp. reported from dogs include L. mexicana, L. donovani, and L. braziliensis. Leishmaniasis can be categorized by two types of diseases in dogs: a cutaneous reaction and a visceral reaction, the most severe form of leishmaniasis. Infection does not invariably lead to illness. In fact, most infected dogs remain asymptomatic and may never develop clinical manifestations. Diagnosis of canine leishmaniasis is based on the presence of clinical signs together with positive specific antibody assay. Due to the close contact of dogs and humans it is important to monitor the presents of Leishmania in the animal population in order to secure safety for humans. In the human field you find 300 000 estimated cases of visceral leishmaniasis (VL) and over 20 000 deaths annually. 1 million cases of cutaneous leishmaniasis (CL) have been reported in the last 5 years. 310 million people are at risk of infection in six countries reporting over 90% VL cases worldwide. Aim: The aim of this work was to develop a serological Lineblot assay to detect IgG and IgM antibodies against Leishmania in serum or plasma samples derived from all mammals, including dogs and humans. Methods: For this approach a set of native antigens and different recombinant antigens (developed by the PhilippsUniversity Marburg) have been used to print Lineblot membranes. The recombinant antigen from Marburg has been designed for high sensitivity and specificity, and it can be used for the differentiation between vaccination and disease state. For confirmation and screening purpose a ELISA system has been developed. To have a point-of- care (POC) device for resource limited setting also lateral flow rapid tests are in development. Both assays are utilizing the recombinant antigen from Marburg. Results: In house sample collection was used for development and evaluation of the assay. In addition, samples and external validations from the University of Marburg have been used. The new Lineblot assay shows a high specificity and sensitivity and is able to differentiate between vaccination and disease. Cross-reactions can be identified more easily. Currently different studies are running in different endemic regions like Brazil, Sudan or India with human and veterinary samples. Preliminary results of these studies will be shown. Conclusion: Here we show the performance characteristic of a newly developed assays. Due to the improved antigen design and test setup a superior assay performance was achieved. This new Leishmania Lineblot can be used to diagnose disease in symptomatic as well as in asymptomatic dogs (and humans) to be able to administer proper treatment. It can also be used for confirmatory testing as well as for the differentiation between disease and vaccination. In areas where Leishmania is endemic and transmitted by insect vectors, it is an important agent of human disease and dogs are 184