Evaluation of a commercial enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against Toxoplasma gondii from naturally and experimentally infected pigs

Background: Toxoplasmosis is one of the most frequent parasitic infections in animals causing reproductive disorders and thus notable economic losses in productivity. Among food animals, pigs along with sheep and goats possess the highest incidence of Toxoplasma gondii cysts in meat, and play a role as a source of human infection. Methods: The commercial ELISA kit (PrioCHECK® Toxoplasma Ab SR, Prionics Schlieren-Zurich, Switzerland) for the detection of specific antibodies against T. gondii in swine serum was compared with a commercial IFAT (indirect fluorescent antibody test) (Toxo-Spot IF, bioMérieux, France), used as the reference test. Results: The kappa value obtained comparing the results performed on sera by ELISA with the by IFAT was 1. By a receiver operating characteristics curve analysis, the commercial ELISA had a relative sensitivity of 100%, and a relative specificity of 100% respect to IFAT. Conclusions: The commercial ELISA showed a very good agreement with the commercial IFAT in the detection of serum antibodies to Toxoplasma in pigs. Our study confirmed the usefulness of the commercial ELISA kit for the detection of antibodies against T. gondii in pigs, representing a valuable tool to improve the diagnostic activity for T. gondii in swine populations at the farm level or at the slaughterhouse, contributing to the control of this widespread infection.