Establishment and Application of an Indirect ELISA for Detecting Getah Virus IgG Antibodies in Swine Based on the E2EP3 Peptide

The Getah virus (GETV) is a mosquito-borne pathogen that infects diverse hosts, including pigs, horses, and humans, which can cause swine reproductive disorders such as abortion and stillbirth, posing a potential threat to animal and public health. Therefore, there is an urgent need for efficient and accurate serological diagnostic methods for surveillance and control of GETV. However, commercial diagnostic kits for swine GETV infection remain unavailable. In this study, we developed a novel enzyme-linked immunosorbent assay (ELISA) based on a GETV-specific epitope peptide (E2EP3) for serological detection. The N-terminally biotinylated E2EP3 peptide was synthesized, and the reaction conditions were systematically optimized, resulting in a cut-off value of 0.363. The assay exhibited no cross-reactivity with Japanese encephalitis virus (JEV), porcine circovirus type 2 (PCV2), porcine circovirus type 3 (PCV3), pseudorabies virus (PRV), or classical swine fever virus (CSFV). It demonstrated good reproducibility and high sensitivity, detecting GETV-positive serum diluted up to 1:640. The overall agreement rate reached 95%, consistent with a conventional recombinant GETV E2 protein-based ELISA. Benefiting from the biotin–streptavidin system, this assay achieved strong signal amplification and low background. Moreover, the procedure is simple, cost-effective, and stable, making it suitable for GETV large-scale serological surveillance and vaccine evaluation.