Comparison of immunofluorescence and enzyme-linked immunosorbent assay and immunoglobulin G avidity techniques for screening of anti: Toxoplasma antibodies among single serum sample pregnant women in Tabriz, Iran

Abstract

Background: Congenital toxoplasmosis is that pregnant women acquire the infection during gestation; diagnosis of the acute infection during pregnancy is a complex subject of maternal toxoplasmosis. Thus, the presence of immunoglobulin G (IgG) and/or IgM Toxoplasma antibodies in a single serum sample drawn during gestation cannot be used to define whether the infection was recently acquired or chronic. Materials and Methods: At this cross-sectional descriptive study, sera of 391 pregnant women examined and compared. They were in an age range of 21-35 years, referred by gynecologists and infectious disease specialists, during March 2012-April 2013. They have referred, 215 (54.98%), 102 (26%), 74 (18.92%) in the first, second and third trimesters of gestation, respectively. For each of them, a questionnaire was completed and serum samples were prepared in an equal condition, examined according to the procedures of indirect immunofluorescence (IIF), enzyme-linked immunosorbent assay (ELISA) and IgG Avidity techniques. Results: We have found 111 (28.38%) seronegative and 280 (71.61%) seropositive cases by IIF and 124 (31.70%) seronegative, 267 (68.28%) seropositive cases by ELISA. The IgG avidity test confirmed 45 (69.23%) and 7 (10.76%) doubtful cases of IgM test in IIF and ELISA techniques. Conclusions: This study highlights how to manage pregnant women with toxoplasmosis, especially in a single serum sample condition.

Keywords

• Enzyme-linked immunosorbent assay
• immunoglobulin G avidity
• Toxoplasmosis-Diagnostic tests-immunofluorescence