Detection of Toxoplasma gondii B1 Gene and IgM in IgG Seropositive Pregnant Women.

ABSTRACT

BACKGROUND: The onset of acute toxoplasmosis in pregnant women may pose a risk to their growing fetuses. The timely diagnosis of infection in managing the disease and preventing its harmful consequences on the fetus is very important. Therefore, the study was conducted to identify acute toxoplasmosis in the pregnant women by detecting the specific IgM antibody and Toxoplasma gondii B1 gene. METHODS: A total of 653 serum samples of women who attended to Fatemieh Hospital of Hamadan University of Medical Sciences were tested for IgG antibodies against Toxoplasma gondii by enzyme-linked immunosorbent as-say (ELISA). The IgG positive specimens were further examined for IgM by ELISA and polymerase chain reaction (PCR) for B1 gene. In the second phase, change in IgG titers was evaluated on 47 IgG positive samples after two weeks. RESULTS: ELISA data showed that 167 out of 653 and 2 out of 167 samples were positive for IgG (25.6%) and IgM (1.2%), respectively. However, PCR detection showed that 36 cases (21.6%) were positive for the B1 gene. Seven out of 47 IgG positive samples showed an increase in the antibody titer and positive for the B1 gene. The most cases of IgG positives and the B1 gene samples were associated with the third trimester of pregnancy with 49.7% and 14%, respectively, and the most common abundance of the B1 gene was 14.4% in the age group of 26 - 35. The most commonly reported clinical symptoms in the B1 gene-positive women were nausea 15 (41.7%), cough 13 (36.1%), headache 12 (33.3%), and vomiting 11 (30.5%). CONCLUSIONS: Using PCR and the B1 gene in serum samples of pregnant women to detect acute toxoplasmosis is a more appropriate and accurate method than IgM antibody.