Phase II validation study of the rK39 ELISA prototype for the diagnosis of canine visceral leishmaniasis in Brazil.

Fernanda Alvarenga Cardoso Medeiros,Gustavo Fontes Paz,Job Alves De Souza Filho,Mayerson Thompson,Fabiano Borges Figueiredo,José Ronaldo Barbosa,Andreza Pain Marcelino,Guilherme Loureiro Werneck,Lucas Edel Donato

doi:10.1590/0102-311x00041320

Abstract

Dogs are the main reservoirs in the domestic transmission cycle of visceral leishmaniasis, and the diagnosis is essential for the effectiveness of the control measures recommended by the Brazilian Ministry of Health. We assessed the diagnostic performance of the ELISA-Vetlisa/BIOCLIN prototype with serum samples from 200 dogs, in triplicate, including symptomatic, oligosymptomatic, asymptomatic, and healthy dogs, originated by two distinct panels (A and B) characterized by parasitological tests as the reference standard. In this study, the prototype kit showed a 99% sensitivity (95%CI: 94.5-100.0) and a 100% specificity (95%CI: 96.4-100.0). The sensitivity of the prototype kit did not vary significantly with the clinical status of the dogs. Considering the final result classification (positive or negative), agreement between the results of repeated tests was almost perfect (kappa = 0.99; 95%CI: 0.98-1.00). ELISA-Vetlisa/BIOCLIN is a promising option for the serological diagnosis of canine visceral leishmaniasis in Brazil.

Highlights

Visceral leishmaniasis (VL) is a neglected tropical disease caused by protozoan parasites of the genus Leishmania
Since 2011, the Brazilian VL control program recommends screening canine visceral leishmaniasis (CVL) with an immunochromatographic test (ICT) followed by the ELISA assay as confirmatory test 4
This study evaluated the performance of this prototype in a sample of dogs, using a well-defined reference standard and blind analysis for the diagnosis of CVL in infected and non-infected dogs from endemic areas of Brazil

Summary

Introduction

Visceral leishmaniasis (VL) is a neglected tropical disease caused by protozoan parasites of the genus Leishmania. In the Americas, VL is caused by Leishmania infantum, transmitted by the bite of phlebotomine vectors, mainly Lutzomyia longipalpis 2, and dogs are the main urban reservoirs 3. Control measures include early diagnosis and treatment of human cases, reactive chemical vector control, education activities, and control of the canine reservoir. In this context, accurate serological diagnosis of canine visceral leishmaniasis (CVL) is of major importance. Public laboratories use the ICT Dual Path Platform rK28 (DPP CVL, Bio-Manguinhos, Rio de Janeiro, Brazil), followed by ELISA with soluble Leishmania major antigen (Bio-Manguinhos). The limited supply of diagnostic kits for ELISA in Brazil represents a problem, mainly for private laboratories

Methods

Results

Conclusion