Comparison of the indirect fluorescent antibody test and modified agglutination test for detection of anti-Toxoplasma gondii antibodies in rats

Abstract

The toxoplasmosis is a zoonosis caused by Toxoplasma gondii and affects a lot of species of carnivores and omnivores, including the human. The rodents are important in the transmition cycle because they act as an infection font to felines, the definitive host of this protozoan. The objective of this work was to evaluate the Modified Agglutination Test (MAT) for the serologic diagnosis of toxoplasmosis in rats, comparing with the Indirect Fluorescent Antibody Test (IFAT), which has been considered the golden standard in animal toxoplasmosis diagnosis. Kappa test was used for comparing the serologic tests (IFAT and MAT) and for determination of cutoff appropriate to MAT in this animal species. 182 rats were caught on local recycling of solid waste and solid residue storage in Londrina city, Paraná. Out of the 182 rats, nine (4.94%) were positive to IFAT at a dilution of 1:16, and 17 (9.34%) and five (2.75%) were reactive to MAT in dilutions 1:25 and 1:50, respectively. The comparison of results between the techniques presented kappa coefficients of 0.26 and 0.55, respectively at 1:25 and 1:50 dilutions of MAT. It can be concluded that the dilution 1:50 is the most suitable to be used as cutoff for detecting T. gondii antibodies in rats using MAT, because agreed with IFAT.