Development and Efficacy Evaluation of an Indirect ELISA Method Based on the Immunodominant Region of the Spike Protein of Porcine Epidemic Diarrhea Virus.

Porcine epidemic diarrhea virus (PEDV) is a major viral pathogen responsible for severe diarrhea and substantial economic losses in the swine industry. Characterized by its high infectivity, pathogenicity and mortality rates in neonatal piglets, PEDV has caused devastating epidemics globally over the past decade. Therefore, development of rapid, sensitive, and specific serological tests is therefore critical for effective disease surveillance and immunity evaluation. In this study, we developed and validated an indirect ELISA using the immunodominant S10AB region of the PEDV spike protein. The assay exhibited acceptable sensitivity, strong reproducibility (CV < 10%) and excellent specificity with no cross-reactivity against other common swine viruses. The test results also exhibited high concordance with virus neutralization tests (AUC = 0.913; kappa = 0.797). In addition, the ELISA was utilized to analyze 1629 field serum samples collected from southwestern China. The results indicated significant regional differences occur regarding PEDV seroprevalence and proved its potential for large-scale seroepidemiological studies. In conclusion, the S10AB-based indirect ELISA developed in the present study provides a reliable, specific, and practical tool for PEDV serodiagnosis and control.