Establishment and Evaluation of Colloidal Gold Immunochromatography Assay for Detection of EV71-IgM

Aim: The HFMD caused by EV71 virus has extremely high lethality and morbidity. EV71's pathogenesis has not understood thoroughly and the antiviral drug has been under development, which led to its emergence as a clinically fatal neurotropic virus. Early diagnosis is one of the main methods to reduce mortality. The aim of this study was to establish and evaluate a colloidal gold immunochromatography for qualitatively detecting the EV71-IgM in serum sample. Method: In this study, the different kinds of coating antigen were the focus of optimization. The pH value, particle size of the colloidal gold and other parameters and materials were also considered to achieve the good performance in detecting strips. The CA16-positive, EV71-positive and negative serum were used to compare and evaluate the accuracy and specificity of strips. Result: The accuracy of the strips coated by EV71-VP1-VP2-VP3 was higher than the EV71-VP1 strips 20%. The specificity of the EV71-VP1 strips was slightly higher than EV71-VP1-VP2-VP3 strips according to CA16 positive serum samples. Compared with commercial strips, this diagnostic method just needed 2 μL serum samples for detection, and the accuracy of the EV71-VP1-VP2-VP3 strips was significantly higher than the commercial strips. Conclusion: The developed method established in this study can apply to early diagnosis of HFMD caused by EV71 virus