Performance evaluation of the VidiaTM toxoplasmosis IgG and IgM assays

Objective: The aim of the present study was to compare the clinical performance of the new VIDIA® Toxoplasmosis assays (bioM´erieux, France) to VIDAS (bioM´erieux, France), Axsym (Abbott, USA) and Liaison (DiaSorin, Italy) assays for both IgG and IgM, using clinical specimens. Methods: A total of 405 frozen and fresh serum samples from 243 pregnant women, 6 pregnant women-HIV infected, 39 healthy adults, 31 infants, 71 immuno-compromised patients and 15 blood donor was used for this retrospective and prospective study. The samples for which at least one equivocal result have been found whatever the method have been excluded for the analysis, as well as the non resolved samples. Sensitivity and specificity of the VIDIA TOXO IgM and IgG were determined, on all sera, in comparison with the VIDAS (routinely used in our laboratory), Axsym and Liaison systems. Results: For clinical samples, sensitivity was found to be 100% for all the four systems for the detection of Toxoplasmosis IgG; regarding Toxoplasmosis IgM, sensitivity was established at 100% for both VIDIAand VIDAS systems, with Axsym we obtained 82.35 and 94.12% with Liaison. The specificity was 99.25% for VIDIA, 98.49% for Axsym and 100% for both VIDAS and Liaison for the detection of toxoplasmosis IgG; regarding TOXO IgM. Regarding the specificity we obtained 100% for VIDIA, VIDAS and LIAISON and 99.73% for Axsym. Conclusion: According to the results obtained during this study, the VIDIA TOXO IgG and VIDIA TOXO IgM assays show an excellent sensitivity and a good specificity.