Parasitic Effects on the Congenital Transmission of Trypanosoma cruzi in Mother–Newborn Pairs

Abstract

Maternal parasitemia and placental parasite load were examined in mother–newborn pairs to determine their effect on the congenital transmission of Trypanosoma cruzi. Parasitemia was qualitatively assessed in mothers and newborns by the microhematocrit test; parasite load was determined in the placental tissues of transmitting and non-transmitting mothers by the detection of T. cruzi DNA and by histology. Compared to transmitter mothers, the frequency and prevalence of parasitemia were found to be increased in non-transmitter mothers; however, the frequency and prevalence of parasite load were higher among the transmitter mothers than among their non-transmitter counterparts. Additionally, serum levels of interferon (IFN)-γ were measured by an enzyme-linked immunosorbent assay (ELISA) in peripheral, placental, and cord blood samples. Median values of IFN-γ were significantly increased in the cord blood of uninfected newborns. The median IFN-γ values of transmitter and non-transmitter mothers were not significantly different; however, non-transmitter mothers had the highest total IFN-γ production among the group of mothers. Collectively, the results of this study suggest that the anti-T. cruzi immune response occurring in the placenta and cord is under the influence of the cytokines from the mother’s blood and results in the control of parasitemia in uninfected newborns.