title: Assessment of diagnostic accuracy of a commercial ELISA for the detection of Toxoplasma gondii infection in pigs compared with IFAT, TgSAG1-ELISA and Western blot, using a Bayesian latent class approach.
abstract: Serological methods are the most commonly used diagnostic tools to detect Toxoplasma gondii infections in pigs. In the absence of a readily available 'gold standard', an estimation of diagnostic accuracy is difficult to assess. A commercial ELISA (PrioCHECK® Toxoplasma Ab porcine ELISA, Prionics, Schlieren, Switzerland) for the diagnosis of T. gondii infection in pigs was evaluated in naturally infected animals from two distinct populations; indoor and outdoor living animals. An assessment of diagnostic accuracy, using a Bayesian latent class approach with adjustment for within indoor and outdoor farm clustering using random effects, was performed. Tests used for comparison were: IFAT; ELISA using native affinity-purified P30 (SAG1) T. gondii tachyzoite surface antigen (TgSAG1-ELISA); and Western blot with T. gondii tachyzoites lysate. The data set comprised 297 pig serum samples across outdoor (n=149) and indoor (n=148) farms in Argentina. The estimated sensitivity and specificity for the commercial ELISA were 98.9% (95% credible interval: 96.2; 100) and 92.7% (95% credible interval: 87.7; 96.6), respectively. The analysis of sera and plasma from pigs (n=6) experimentally inoculated with 5,000 T. gondii oocysts revealed a pronounced antibody response beginning 2 weeks p.i. until the end of the observation period (11 weeks p.i.) in all animals. Meat juice obtained from inoculated animals after euthanasia also tested positive. These results suggest that the PrioCHECK® Toxoplasma Ab porcine ELISA may be a useful tool to perform serological diagnosis of T. gondii infections in pigs to control Toxoplasma infection in pigs and humans.
authors.affiliation: Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, CH-8057 Zurich, Switzerland. walter.basso@access.uzh.ch
authors.forename: Walter
authors.initials: W
authors.lastname: Basso
authors.forename: Sonja
authors.initials: S
authors.lastname: Hartnack
authors.forename: Lais
authors.initials: L
authors.lastname: Pardini
authors.forename: Pavlo
authors.initials: P
authors.lastname: Maksimov
authors.forename: Bretislav
authors.initials: B
authors.lastname: Koudela
authors.forename: Maria C
authors.initials: MC
authors.lastname: Venturini
authors.forename: Gereon
authors.initials: G
authors.lastname: Schares
authors.forename: Xaver
authors.initials: X
authors.lastname: Sidler
authors.forename: Fraser I
authors.initials: FI
authors.lastname: Lewis
authors.forename: Peter
authors.initials: P
authors.lastname: Deplazes
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D001118:Argentina; D015153:Blotting, Western / Q000379:methods*; D019411:Clinical Laboratory Techniques / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D012680:Sensitivity and Specificity; D044967:Serum / Q000276:immunology; D013552:Swine; D014122:Toxoplasma / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000175:diagnosis*; D014730:Veterinary Medicine / Q000379:methods*
chemical_list: D000913:Antibodies, Protozoan