Antigen-detection ELISA performance versus virus evolution V.Mioulet, A.Morris, B.Wood, B.Thapa, A.Gray, L.Henry, N.J.Knowles, J.Wadsworth, D.P.King

WHY? Serotyping done using pAg-ELISA In the last few years this test failed to serotype a number of samples Is there a pattern? Samples logged and sets identified Ctrls O A C SAT 1 SAT 2 SAT 3 ASIA 1 SVDV

EXAMPLE: O/CATHAY % No issues in serotyping using polyclonal Ag-ELISA Low to borderline OD values on standard Ag-ELISA / Confirmation may have been required using the integrin-mAb ELISA Additional ELISA required for determination of serotype

CONCLUSIONS Best practice to not rely on a single test for serotyping Tests in use should be subjected to ongoing validation against circulating field strains Highlights the importance of ongoing work to develop and validate new assays and reagents to detect current circulating strains of FMDV