Further validation of 2 non-structural protein-specific antibody tests for diagnosis and surveillance of foot-and-mouth disease in the United States

Authors: Chung, Chungwon; BAGG, RYAN - Animal And Plant Health Inspection Service (APHIS); Schumann, Kate; BLAKEMORE, LESLIE - Animal And Plant Health Inspection Service (APHIS); Beauchamp, Madison

Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2024
Publication Date: 8/17/2024
Citation: Chung, C.J., Bagg, R., Schumann, K.R., Blakemore, L., Beauchamp, M.B. 2024. Further validation of 2 non-structural protein-specific antibody tests for diagnosis and surveillance of foot-and-mouth disease in the United States Journal of Veterinary Diagnostic Investigation. https://doi.org/10.1177/10406387241266900.
DOI: https://doi.org/10.1177/10406387241266900

Interpretive Summary: Foot-and-Mouth Disease (FMD) is an extremely important economic threat to the livestock industry. Due to the potential application of vaccines using partially purified structural proteins of FMDV, it is important to test with an assay that detects antibodies against non-structural proteins of FMDV. This method differentiates between infected and vaccinated animals (DIVA). In this study, both the VMRD and Priocheck® FMDV antibody ELISAs were satisfactorily validated per World Organization for Animal Health recommended criteria. These results support that both the VMRD 3B cELISA and the PrioCheck 3ABC cELISA are acceptable as a validated assay for sero-surveillance and diagnosis of FMD in the United States.

Technical Abstract: Foot-and-Mouth Disease (FMD) is a highly contagious disease affecting cloven-hoofed animals. FMD poses an economic threat to the livestock industry in the United States of America (USA). Due to the potential use of vaccines composed of partially purified structural proteins of the FMD virus (FMDV), it is important to test with a competitive enzyme-linked immunosorbent assay (ELISA) that detects antibodies against non-structural proteins (NSP) of FMDV. This study extends the diagnostic validation of the PrioCHECK® ELISA and the VMRD 3B ELISA. Diverse serum sample sets from bovine, porcine, and other cloven-hoofed animals were used to evaluate the analytical specificity and sensitivity, diagnostic specificity and sensitivity, and differentiation of infected from vaccinated animals (DIVA) per validation guidelines outlined by the World Organization for Animal Health (WOAH). The VMRD and PrioCHECK® ELISAs demonstrated 100% analytical specificity against sera collected from animals infected or immunized with other porcine and bovine viruses. The analytical sensitivity of the VMRD ELISA was relatively higher than the PrioCHECK® ELISA. The diagnostic specificity of PrioCHECK® ELISA was relatively higher compared to the VMRD ELISA; However, the diagnostic sensitivity for the VMRD ELISA was relatively higher compared to PrioCHECK® ELISA. Both VMRD and PrioCheck® ELISAs have DIVA capability based on the evaluation using limited sera from bovine and porcine animals vaccinated with NSP-depleted inactivated FMDVs. Both VMRD and Priocheck® ELISA assays can be used for serodiagnosis of FMDV at the Foreign Animal Disease Diagnostic Laboratory (FADDL) and within the National Animal Health Laboratory Network (NAHLN) laboratories.