Development of an indirect competitive ELISA method based on ORF2 detecting the antibodies of novel goose astrovirus

Goose astrovirus (GAstV) characterized by articular and visceral gout, is an emerging pathogen with a wide distribution on mainland China, leading to serious economic losses in the goose-raising industry. Because vaccines to prevent GAstV infections are not available currently, early diagnosis is critical when treating symptomatic geese and in preventing GAstV transmission. In this context, a highly sensitive indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a monoclonal antibody (mAb) to detect GAstV-specific antibodies from geese was developed, and the detections were optimized. A series of experiments proved that the ic-ELISA shows excellent diagnostic performance and discriminatory power with high sensitivity and specificity. The ic-ELISA for GAstV detection was applied on 67 field serum samples, and comparing the detection results with the virus neutralization test verified the accuracy of the ic-ELISA. The correlation coefficient between the ic-ELISA and the virus neutralization test was 80%, demonstrating the proposed ic-ELISA method could be a useful and effective tool for the diagnostic, serological epidemiological investigation and immune monitoring of the GAstV in goose-producing regions.