"Synthetic gp90 peptide ELISA for equine infectious anemia virus: Improved sensitivity and risk factor insights"

Equine infectious anemia virus (EIAV) is a globally significant equine pathogen, and its control relies on effective serological surveillance. The agar gel immunodiffusion (AGID) test, the WOAH-prescribed method, has limitations in sensitivity. This study developed and validated an indirect ELISA using a synthetic peptide derived from a conserved region of the EIAV gp90 surface glycoprotein. The assay was evaluated using 773 horse sera from the Metropolitan Zone of the Valley of Mexico and compared to the AGID test. The gp90-EIAV ELISA demonstrated a sensitivity of 85.3 % and a specificity of 97.9 %, identifying 29.4 % more seropositive samples than AGID (p = 0.044). Statistical agreement between tests was substantial (κ = 0.73). Risk factor analysis and cluster analysis identified a high-risk group of < 4-year-old horses, with cases geographically clustered in regions characterized by a temperate climate with summer rains. The synthetic gp90 peptide-based ELISA proved to be a superior screening tool, offering enhanced sensitivity for detecting subclinical infections. Its implementation could significantly improve EIAV surveillance programs by enabling early detection and targeted monitoring of high-risk populations, thereby helping to reduce viral transmission.