Immunoparasitological evaluation of Trichinella spiralis infection during human pregnancy:: a small case series

The clinical background, vertical transmission of Trichinella spiralis and helminthotoxic activity of sera were evaluated in four pregnant women infected at different gestation times. Parasitological and immunological. parameters were analyzed. Patients presented clinical symptoms and a seroconversion pattern typical of Trichinella infection, independently of the gestation trimester. All patients, including one patient treated with mebendazote, gave birth to healthy infants at full term. Studies performed in placentas and umbilical cords by artificial digestion and/or immunofluorescence did not reveal the presence of parasites or parasite antigens. Specific antibodies were found in placental extraction and maternal. sera by immunofluorescence, ELISA and/or immunoelectrotransfer blot assay. Specific IgG, IgE and IgA were found in the umbilical cord sera. One umbilical cord demonstrated immune-complexed specific IgM, and circulating parasite antigens were found in the corresponding infant up to 10 months after birth. Patients' sera were able to kilt newborn larvae in cytotoxicity assays, even in the absence of specific antibodies; this effect was abrogated by mifepristone. The results suggest that in human trichinellosis during pregnancy there is an enhanced helminthotoxicity to newborn larvae, dependent in part on progesterone, leading to a mild or moderate course of the infection. The results also indicate that the transplacental passage of migrating larvae is possible. (C) 2008 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.