ESTABLISHMENT OF A TYPING ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR FOOT-AND-MOUTH-DISEASE ANTIGEN, USING REAGENTS AGAINST VIRUSES ENDEMIC IN THAILAND

Antisera were produced at a central laboratory in Thailand against the endemic serotypes (O, A and Asia 1) of foot and mouth disease (FMD) v irus. At a regional veterinary laboratory, these antisera were used in an indirect sandwich enzyme-linked immunosorbent assay (ELISA) for th e detection and serotyping of FMD virus (FMDV) antigen. ELISA readings of <0.10 optical density (OD) units were considered negative. This wa s verified using fifty tissue samples which were known to be negative for FMDV. The highest mean sample value for three different dilutions was 0.02 OD units. Of a total of 93 samples submitted for antigen typi ng, 80 (86%) tested positive by ELISA and 13 (14%) were negative. No F MDV was detected in ELISA-negative samples following attempted tissue- culture virus isolation.