No abstract

In this study, we evaluated a new immunoassay for the automated detection of anti-toxoplasma IgG and IgM with Immulite 2000 (DPC-Siemens, La Garenne-Colombes, France). We tested 280 sera from 112 patients with past infection (PI), 40 PI with residual IgM, 75 seronegatives, 16 infants (31 sera) monitored for neonatal screening of congenital toxoplasmosis, and 13 patients with recent seroconversion (SC) (22 sequential sera). Detection sensitivity and specificity for IgG were 99 and 100%, respectively. IgG titers obtained with Immulite 2000 were higher than with Vidas (BioMérieux, Marcy I'Etoile, France) and Access (Beckman-Coulter, Villepinte, France) (paired Wilcoxon test z=4.44 and z=3.67, respectively, P<0.001). IgM specificity was 100%. Detection sensitivity for IgM was 100% in the SC group, 86% in congenitally infected infants, and 75% in PI with persistent IgM. IgM detection seemed less prolonged in time than with the IgM Access and ISAGA IgM techniques.