title: The Rapid Test Based on Leishmania infantum Chimeric rK28 Protein Improves the Diagnosis of Canine Visceral Leishmaniasis by Reducing the Detection of False-Positive Dogs.
abstract: Visceral Leishmaniasis (VL) has spread to many urban centers worldwide. Dogs are considered the main reservoir of VL, because canine cases often precede the occurrence of human cases. Detection and euthanasia of serologically positive dogs is one of the primary VL control measures utilized in some countries, including Brazil. Using accurate diagnostic tests can minimize one undesirable consequence of this measure, culling false-positive dogs, and reduce the maintenance of false-negative dogs in endemic areas. In December 2011, the Brazilian Ministry of Health replaced the ELISA (EIE CVL) screening method and Indirect Immunofluorescence Test (IFI CVL) confirmatory method with a new protocol using the rapid DPP CVL screening test and EIE CVL confirmatory test. A study of diagnostic accuracy of these two protocols was done by comparing their performance using serum samples collected from a random sample of 780 dogs in an endemic area of VL. All samples were evaluated by culture and real time PCR; 766 out of the 780 dogs were tested using the previous protocol (IFI CVL + EIE CVL) and all 780 were tested using the current protocol (DPP CVL + EIE CVL). Performances of both diagnostic protocols were evaluated using a latent class variable as the gold standard. The current protocol had a higher specificity (0.98 vs. 0.95) and PPV (0.83 vs. 0.70) than the previous protocol, although sensitivity of these two protocols was similar (0.73). When tested using sera from asymptomatic animals, the current protocol had a much higher PPV (0.63 vs. 0.40) than the previous protocol (although the sensitivity of either protocol was the same, 0.71). Considering a range of theoretical CVL prevalences, the projected PPVs were higher for the current protocol than for the previous protocol for each theoretical prevalence value. The findings presented herein show that the current protocol performed better than previous protocol primarily by reducing false-positive results.
authors.affiliation: Laboratório de Patologia e Biointervenção, Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.|Departamento de Medicina Veterinária Preventiva e Produção Animal, Escola de Medicina Veterinária e Zootecnia, Universidade Federal da Bahia, Salvador, Bahia, Brazil.|Instituto de Ciência e Tecnologia de Doenças Tropicais, INCT-DT, Bahia, Brazil.
authors.forename: Deborah Bittencourt Mothé
authors.initials: DB
authors.lastname: Fraga
authors.affiliation: Laboratório de Patologia e Biointervenção, Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.
authors.forename: Luciano Vasconcellos
authors.initials: LV
authors.lastname: Pacheco
authors.affiliation: Laboratório de Patologia e Biointervenção, Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.
authors.forename: Lairton Souza
authors.initials: LS
authors.lastname: Borja
authors.affiliation: Instituto de Matemática, Departamento de Estatística, Universidade Federal da Bahia, Bahia, Brazil.
authors.forename: Pétala Gardênia da Silva Estrela
authors.initials: PG
authors.lastname: Tuy
authors.affiliation: Laboratório de Patologia e Biointervenção, Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.
authors.forename: Leila Andrade
authors.initials: LA
authors.lastname: Bastos
authors.affiliation: Laboratório de Patologia e Biointervenção, Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.
authors.forename: Manuela da Silva
authors.initials: Mda S
authors.lastname: Solcà
authors.affiliation: Instituto de Matemática, Departamento de Estatística, Universidade Federal da Bahia, Bahia, Brazil.
authors.forename: Leila Denise Alves Ferreira
authors.initials: LD
authors.lastname: Amorim
authors.affiliation: Laboratório de Patologia e Biointervenção, Centro de Pesquisas Gonçalo Moniz, FIOCRUZ, Salvador, Bahia, Brazil.|Instituto de Ciência e Tecnologia de Doenças Tropicais, INCT-DT, Bahia, Brazil.
authors.forename: Patrícia Sampaio Tavares
authors.initials: PS
authors.lastname: Veras
mesh_terms: D000818:Animals; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000175:diagnosis / Q000469:parasitology*; D004285:Dogs; D005189:False Positive Reactions; D018314:Leishmania infantum / Q000302:isolation & purification / Q000378:metabolism*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D015800:Protozoan Proteins / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*
chemical_list: D015800:Protozoan Proteins; D011994:Recombinant Proteins