[Congenital toxoplasmosis: value of modern IgM serodiagnosis is from the example of problem cases].

Congenital toxoplasmosis may be symptomatic or asymptomatic at the time of birth. In the latter case late manifestations may occur which can be avoided by early diagnosis and treatment. In comparison with the IgM-IFT we demonstrate the specificity and high sensitivity of a recently available immunosorbent agglutination assay (ISAGA) for the detection of IgM against toxoplasma. We also present evidence for the high diagnostic value of the ISAGA in cases where congenital toxoplasmosis is suspected. Based on the presented data we propose a pattern of diagnostic methods for the diagnosis or exclusion of congenital toxoplasmosis in newborns.