Recombinant envelope protein (rgp90) ELISA for equine infectious anemia virus provides comparable results to the agar gel immunodiffusion

► A recombinant envelope protein (rgp90) of equine infectious anemia virus was expressed in E. coli. ► The rgp90 was evaluated in an enzyme-linked immunosorbent assay (ELISA) with 1160 horse serum samples and compared to the agar gel immunodiffusion (AGID) test. ► There was an excellent agreement (95.42%) between the ELISA results using rgp90 and AGID. ► The relative sensitivity and specificity of the ELISA were 96.1% and 96.4%, respectively.