الفهرس | Only 14 pages are availabe for public view |
Abstract Toxoplasma gondii is an important apicomplexan parasite in human that if contracted during pregnancy places the developing fetus at risk of congenital infection and can lead to fetal wastage or congenital malformation. The main objective of this work was to assess the diagnostic value of serology and molecular DNA amplification of B1 gene by PCR to detect recent Toxoplasma infections in both pregnant mothers and newborn babies. A total of 90 females and their respective fetuses and neonates; of whom 57 females with complicated obstetric history and 33 females with normal full term pregnancy; were included in the present study. Serum samples from pregnant women at delivery were screened for Toxoplasma-specific immunoglobulin G (IgG) using MEIA assay, and IgM and IgA using ELISA assay. Also placental testing for Toxoplasma by PCR or histopathological examination was done. The early neonatal diagnostic procedures included cord and peripheral blood serological testing for anti-Toxoplasma IgA and IgM-ELISA antibodies, and neonatal blood molecular PCR testing for Toxoplasma nucleic acids. Out of the 90 cases tested; 24.5%, 7.8% and 6.7% were specific IgG, IgM and IgA antibodies seropositive respectively. PCR placental examination was positive for 29.9% of the females with complicated obstetric history and 3.0% of the females with normal full term pregnancy. Toxoplasma parasites were not detected in any of the examined placentae sections. By ELISA, cord blood serology detected IgM and IgA in 8.2% and 12.3% of the samples respectively, and neonatal blood serology detected 7.5% and 11.3% positive specific IgM and IgA respectively. On the basis of amplification of a gene sequence specific for T. gondii, 27.0% conception products of aborted and intrauterine dead fetuses and 15.1% blood samples of newborns were positive for Toxoplasma nucleic acid. In conclusion, there is no single test that can be used alone for the define diagnosis of acute Toxoplasma infection during pregnancy or in early neonates and the study demonstrates the possibility of defining and selecting the high-risk cases by combining T. gondii polymerase chain reaction and serological techniques to formulate a specific approach so that each one of the two tests can fulfill the gap of the other test. Key Words: Toxoplasma gondii, toxoplasmosis in pregnancy, DNA, B1 gene, PCR, ELISA, congenital toxoplasmosis, postnatal diagnosis, IgA, IgM, IgG. |