Real-time PCR in the diagnosis of congenital toxoplasmosis

The diagnosis of congenital toxoplasmosis presents limitations and therefore new options are necessary. The analysis of amniotic fluid by real-time PCR has already proved effective for con-firmation of fetal infection. However, its performance in other biological samples is not clear yet. The aim of this study is to better understand the role of real-time PCR in the blood of the mother and newborn as well as in the amniotic fluid and placenta in the diagnosis of congeni-tal toxoplasmosis. This is a descriptive cohort study of pregnant women with toxoplasmosis followed up in Rio de Janeiro, Brazil. Real-time PCR was performed in samples of maternal blood, amniotic fluid, placenta, and blood of newborns. In addition, histopathological examina-tion of placentas was performed, and data collected from babies were collected. 116 pregnant women were followed up and 298 samples were analyzed. One (0.9%) pregnant woman pre-sented positive PCR in the blood, 3 (3.5%) in the amniotic fluid, 1 (2.3%) in the placenta and no newborn had positive PCR in the blood. Histopathological study was suggestive of toxoplasmo-sis infection in 24 (49%) placentas. Six (5.2%) newborns were diagnosed with congenital toxo-plasmosis, and only cases with positive PCR in the amniotic fluid had correlation of the PCR result with the diagnosis of congenital infection. Both maternal and blood samples of new-borns and placenta did not prove to be promising in the diagnosis of congenital toxoplasmosis. Further studies are needed to evaluate the real role of molecular diagnosis in other biological materials rather than the amniotic fluid. (c) 2023 Sociedade Brasileira de Infectologia. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)