title: Serological diagnosis of canine leishmaniosis: comparison of three commercial ELISA tests (Leiscan, ID Screen and Leishmania 96), a rapid test (Speed Leish K) and an in-house IFAT.
abstract: BACKGROUND
  Speed Leish K is used as a serological screening test for Leishmania infection prior to vaccination. Limited comparative serological studies with Speed Leish K have been performed. The aim of this study was to evaluate the diagnostic performance of four commercially available serologic tests including ELISAs (Leiscan, ID Screen and Leishmania 96), a rapid test (Speed Leish K) and an in-house IFAT for the detection of specific antibodies against Leishmania infantum antigen in dogs in different states of infection.
  
  
  METHODS
  Sick infected dogs (n = 36), healthy infected dogs (n = 18), L. infantum seropositive dogs with low to high levels of antibodies (n = 53), dogs seropositive to other pathogens (to evaluate cross reaction) (n = 14) and uninfected dogs from a non-endemic area (n = 50) and from an endemic area (n = 32) were analysed by the serological methods mentioned above.
  
  
  RESULTS
  The sensitivity was as follows: ID Screen (0.953), Leiscan and Leishmania 96 (0.925), IFAT (0.869) and Speed Leish K (0.636). The maximum specificity (1.000) was attained for all diagnostic tests except the Leishmania 96 (0.896) and IFAT (0.917). The accuracy was as follows: ID Screen (0.975), Leiscan (0.961), Leishmania 96 (0.911), IFAT (0.892) and Speed Leish K (0.808). In relation to the area under the ROC curve (AUC-ROC), the maximum value was attained with the ID Screen (0.993) closely followed by Leiscan (0.990), then, Leishmania 96 (0.962), IFAT (0.926) and Speed Leish K (0.818). For the Kappa index, the best result was obtained by the ID Screen (0.951) followed by Leiscan (0.921), Leishmania 96 (0.822), IFAT (0.783) and Speed Leish K (0.622). Statistically significant differences were found between the AUC-ROC of quantitative serological tests and the only qualitative rapid test evaluated. There were also statistically significant differences between AUC-ROC of the ELISAs (ID Screen and Leiscan) and IFAT.
  
  
  CONCLUSIONS
  Leiscan and ID Screen had superior diagnostic performance measures than IFAT and all quantitative serological tests were superior when compared to Speed Leish K. Thus, Speed Leish K may be considered a less valuable screening test prior to vaccination as it may result in vaccination of seropositive dogs and in some cases seropositive sick dogs.
authors.affiliation: Departament de Medicina i Cirurgia Animals, Facultat Veterinaria, Universitat Autònoma de Barcelona (UAB), Barcelona 08193, Cerdanyola, Spain. laia.solano@uab.cat.
authors.forename: Laia
authors.initials: L
authors.lastname: Solano-Gallego
authors.forename: Sergio
authors.initials: S
authors.lastname: Villanueva-Saz
authors.forename: Marta
authors.initials: M
authors.lastname: Carbonell
authors.forename: Michele
authors.initials: M
authors.lastname: Trotta
authors.forename: Tommaso
authors.initials: T
authors.lastname: Furlanello
authors.forename: Alda
authors.initials: A
authors.lastname: Natale
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology; D003429:Cross Reactions; D004283:Dog Diseases / Q000175:diagnosis* / Q000469:parasitology; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary*; D018314:Leishmania infantum / Q000276:immunology / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary*; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan