Evaluation of IgM-based ELISA for the Detection of Strongyloidiasis by NIE Protein

Strongyloidiasis is a neglected disease caused by Strongyloides stercoralis. Fast and robust detection of this parasite can avoid its auto-infection cycle and therefore from the high parasitic load. The culture of stool and stool-based microscopy techniques are the most used methods for parasite diagnosis; however, these methods are not sensitive enough. Immunological methods are more sensitive diagnostic tools and can be employed for the detection of this parasite. Since IgG4 immunoreactive protein (NIE) is a major pathogenicity factor of the parasite, in the present study, an IgM-ELISA method was developed to investigate the efficiency of anti-NIE IgM antibodies in the detection of Strongyloides stercoralis. For this aim, 50 serum samples were gathered from positive patients along with 50 serum patients from healthy people. IgM antibodies were detected by using the ELISA technique and the data were analyzed by statistical analyses. Statistical analyses showed that IgM-ELISA was able to diagnose the disease with the sensitivity and specificity of 65.0%. The developed IgM-ELISA method was relatively but not sufficiently successful at a robust diagnosis of strongyloidiasis. However, the sensitivity and specificity of this method were not good enough to be considered a reliable test for the diagnosis of the disease compared to the IgG- ELISA.