Evaluation of an immunochromatographic serologic test to detect the presence of anti-Toxoplasma gondii antibodies in cats.

Abstract

Toxoplasmosis is a protozoan disease caused by Toxoplasma gondii. Different T. gondii confirmatory techniques, including serologic methods, are available to detect the presence of the parasite. Among serology techniques, immunochromatographic rapid testing could be a reliable alternative to serologic laboratory techniques. This study evaluated a commercial immunochromatographic test (FASTest TOXOPLASMA g) in seronegative and seropositive cats. Two indirect immunofluorescence antibody reference tests, an in-house technique, and a commercial test were used to classify 292 feline serum samples. The rapid test was evaluated in different groups of cats, including healthy seronegative cats (n=121), seropositive cats with variable anti-Toxoplasma antibodies (n=146), and cats with positive serologic results for other pathogens (n=25). The sensitivity, specificity, accuracy, receiver operating characteristic curves, and kappa statistics were analyzed as performance measures. Of the 292 samples, 146 were classified as T. gondii seropositive and 146 as T. gondii seronegative. Concordant results were obtained for all samples using immunofluorescence antibody tests. The diagnostic measures of this rapid test showed 98.63% sensitivity and 100% specificity, and 99.32% accuracy. The kappa statistics value was 0.986, and the area under the receiver operating characteristic curve was 0.993. This rapid test showed diagnostic measurements similar to those of traditional quantitative serologic methods. In situations where laboratory techniques are not available, this test, under clinical conditions, could be a useful alternative to obtain accurate results rapidly.