An indirect enzyme-linked immunosorbent assay (I-ELISA) based on the VP2 protein of duck hepatitis A virus type 3 (DHAV-3) was established in this study. The optimal dilutions of antigen, serum and goat anti-duck IgG conjugate were 1:1600 (2.23 μg/mL), 1:160 and 1:2000, respectively. The optimal blocking buffer was 1% skim milk. The cut-off value for the method was 0.25, and the analytical sensitivity of the method was 1:5120. The results of specific evaluation showed that except for DHAV-1, DHAV-3 antisera did not cross-react with any other common duck-sensitive pathogens, indicating that this method can be used to detect DHAV-3 and DHAV-1 antibodies. The coefficients of variation (CVs) were lower than 10 %. The coincidence rate between the VP2-DHAV-3-ELISA and the neutralization test was 93.3 %. In summary, the I-ELISA method based on VP2 protein has high sensitivity, specificity, and coincidence rate compared with the neutralization test and has advantages in serum monitoring. The I-ELISA method based on VP2 protein provides a simple and rapid method for the detection of anti-DHAV antibodies and the epidemiological monitoring of DHAV.

本研究建立了基于鸭甲型肝炎病毒3型（DHAV-3）VP2蛋白的间接酶联免疫吸附测定（I-ELISA）。抗原、血清和羊抗鸭 IgG 结合物的最佳稀释度分别为 1:1600 (2.23 μg/mL)、1:160 和 1:2000。最佳封闭缓冲液为 1% 脱脂牛奶。该方法的截断值为 0.25，该方法的分析灵敏度为 1:5120。特异性评价结果显示，除DHAV-1外，DHAV-3抗血清不与任何其他常见鸭敏感病原体发生交叉反应，表明该方法可用于检测DHAV-3和DHAV-1抗体。变异系数 (CV) 低于 10%。 VP2-DHAV-3-ELISA与中和试验的符合率为93.3%。综上所述，基于VP2蛋白的I-ELISA方法与中和试验相比具有较高的敏感性、特异性和符合率，在血清监测中具有优势。基于VP2蛋白的I-ELISA方法为抗DHAV抗体的检测和DHAV的流行病学监测提供了一种简单、快速的方法。