High accuracy of an ELISA test based in a flagella antigen of Leishmania in serodiagnosis of canine visceral leishmaniasis with potential to improve the control measures in Brazil – A Phase II study
Open Access
- 26 October 2018
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLoS Neglected Tropical Diseases
- Vol. 12 (10), e0006871
- https://doi.org/10.1371/journal.pntd.0006871
Abstract
Canine Visceral leishmaniasis (CVL) is a serious public health problem, thus for its control, the Ministry of Health in Brazil recommends the rapid diagnosis and euthanasia of seropositive dogs in endemic areas. Therefore, our group had previously selected six recombinant proteins (rLci1, rLci2, rLci4, rLci5, rLci8, and rLci12) due to their high potential for CVL diagnostic testing. The present study aims to produce an immunodiagnostic test using the aforementioned antigens, to improve the performance of the diagnosis of CVL recommended by Brazilian Ministry of Health. To evaluate the recombinant proteins in the serological assays, positive and negative samples were selected based on parasitological test (culture) and molecular test (qPCR) of splenic aspirate. Initially, we selected 135 dog serum samples, 73 positives (symptomatic and asymptomatic) and 62 negatives to screen recombinant proteins on ELISA platform. Then, for rLci5 ELISA validation, 361 serum samples collected in a cross-sectional study were selected, being 183 positives (symptomatic and asymptomatic) and 178 negatives. In the screening of the recombinant proteins, rLci5 was the only protein to present a performance statistically higher than the performance presented by EIE-LVC test, presenting 96% (IC 95%; 85–99%) vs. 83% (IC 95%; 69–92%) of sensitivity for symptomatic dogs, 71% (IC 95%; 49–97%) vs. 54% (IC 95%; 33–74%) for asymptomatic dogs and 94% (IC 95%; 83–99%) vs, 88% (IC 95%; 76–95% of specificity. Thus, the rLci5 protein was selected to compose a final ELISA test. Validation of rLci5 ELISA showed 87% (IC 81–91%) of sensitivity, 94% (IC 95%; 90–97%) of specificity and 90% accuracy. Testing the EIE-LVC with the same validation panel, we observed a lower performance when compared to ELISA rLci5 (sensitivity of 67% (IC 95%; 59–74%), specificity of 87% (IC 95%; 81–92%), and accuracy of 77%). Finally, the performance of current CVL diagnostic protocol recommended by Brazilian Ministry of Health, using DPP-LVC as screening test and EIE-LVC as confirmatory test, was compared with a modified protocol, replacing EIE-LVC by rLci5 ELISA. The current protocol presented a sensitivity of 59% (IC 95%; 52–66%), specificity of 98% (IC 95%; 95–99%) and accuracy of 80% (IC 95%; 76–84%), while the modified protocol presented a sensitivity of 71% (IC 95%; 63–77%), specificity of 99% (IC 95%; 97–100%) and accuracy of 86% (IC 95%; 83–89%). Thus, we concluded that rLci5 ELISA is a promising test to replace EIE-LVC test and increase the diagnostic performance of CVL in Brazil. Visceral leishmaniasis is a tropical disease caused by the protozoan parasite Leishmania infantum, which is transmitted to humans through the bite of infected sand flies. Infected dogs are considered the main urban reservoir of parasite. Identification and euthanasia of infected dogs is one of the main strategies for VL control recommended by the Brazilian Ministry of Health. Hence, to improve the efficacy of control measures, it is essential an accurate diagnose of naturally infected dogs in endemic areas. Herein, we sought to produce a new immunodiagnostic test using recombinant antigens of Leishmania infantum to improve the performance of the diagnosis of CVL recommended by Brazilian Ministry of Health.Keywords
Funding Information
- Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais (576269/2008)
- Fundação de Amparo à Pesquisa do Estado da Bahia (JCB0010/2013)
This publication has 23 references indexed in Scilit:
- Evaluation of a novel chromatographic immunoassay based on Dual-Path Platform technology (DPP® CVL rapid test) for the serodiagnosis of canine visceral leishmaniasisTransactions of the Royal Society of Tropical Medicine and Hygiene, 2012
- Characterization of Novel Leishmania infantum Recombinant Proteins Encoded by Genes from Five Families with Distinct Capacities for Serodiagnosis of Canine and Human Visceral LeishmaniasisThe American Journal of Tropical Medicine and Hygiene, 2011
- QUADAS-2: A Revised Tool for the Quality Assessment of Diagnostic Accuracy StudiesAnnals of Internal Medicine, 2011
- High-Throughput Analysis of Synthetic Peptides for the Immunodiagnosis of Canine Visceral LeishmaniasisPLoS Neglected Tropical Diseases, 2011
- Transmission, reservoir hosts and control of zoonotic visceral leishmaniasisParasitology, 2009
- Retooling Leishmania metabolism: from sand fly gut to human macrophageThe FASEB Journal, 2007
- Comparative Evaluation of Enzyme-Linked Immunosorbent Assays Based on Crude and Recombinant Leishmanial Antigens for Serodiagnosis of Symptomatic and Asymptomatic Leishmania infantum Visceral Infections in DogsClinical and Vaccine Immunology, 2007
- A strategy for identifying serodiagnostically relevant antigens of Leishmania or other pathogens in genetic librariesBiologicals, 2007
- Assessment of an optimized dog-culling program in the dynamics of canine Leishmania transmissionVeterinary Parasitology, 2004
- Urbanização da leishmaniose visceral em Belo HorizonteArquivo Brasileiro de Medicina Veterinária e Zootecnia, 2001