Selection of foot and mouth disease antisera for diagnosis by ELISA

The World Reference Laboratory (WRL) for foot and mouth disease receives vesicular virus samples from throughout the world for the diagnosis and serotype identification of foot and mouth disease virus (FMDV). These samples may contain strains of virus which are widely different antigenically. To optimise the efficiency of laboratory diagnosis, it is essential that the antisera used in diagnostic procedures be specific, of high titre and broadly reactive within that serotype in order to detect all strains of virus currently circulating in the field. Experience and investigation by complement fixation have shown that antisera against certain strains of FMDV fulfil this requirement better than others (3). Many of these reagents had been produced from the hyperimmunisation of guinea pigs (1). The preferred method for the production of reference antisera now involves the utilisation of inactivated and purified FMDV antigens. In addition, over the last two years an enzyme-linked immunosorbent assay (ELISA; 9) has been extensively evaluated and adopted for routine use (6). Rabbit and guinea pig antisera to inactivated 146S antigens have consequently been produced from the current (1985) diagnostic strains and those suggested as alternatives (3). These reagents have been assessed in the ELISA to extend previous studies for the selection of sera for diagnosis.