Evaluation of the solid phase competition ELISA for detecting antibodies against the six foot-and-mouth disease virus non-O serotypes

The solid-phase competition ELISA (SPCE) has been evaluated in both screening and titration assay formats for detecting antibodies against foot-and-mouth disease virus (FMDV) for the six non-O serotypes A, C, SAT 1, SAT 2, SAT 3 and Asia 1. Cut-off values were determined as a percentage inhibition of 40 for the SAT serotypes and 50 for serotypes A, C and Asia 1, which gave rise to specificity values ranging from 99.41% to 99.9% for the different serotypes. The relative sensitivity between the SPCE and LPBE/virus neutralisation test was 100%/109%. Antiserum titres derived by the SPCE for samples of serotypes O, A22 and Asia 1 were more than 11, 1 and 5 times of those determined by virus neutralisation test, respectively. This study indicated that the non-type O SPCEs have sufficient sensitivities and specificities for use as serological diagnostic tests for the qualitative and quantitative detection of antibodies against FMDV.

► This study evaluated the solid-phase competition ELISA (SPCE) for detecting antibodies against foot-and-mouth disease virus (FMDV) for the six non-O serotypes A, C, SAT 1, SAT 2, SAT 3 and Asia 1 as a screening and a titration assays. ► It was shown that the SPCE has retained the high sensitivity of the liquid phase blocking ELISA (LPBE) and the gold standard virus neutralisation test, while having a better specificity than the LPBE and the advantages of easier performing, robust and no requirement of the high containment facility. ► The SPCE can detect antibodies of a wide range of subtypes within serotypes. It has been used as the primary serological diagnostic tests in the WRL/EURL for FMD during any FMD suspect episodes and during the post-outbreak serosurveillance in 2001 and 2007 UK FMD outbreak. ► The SPCE test can be a sensitive, specific, speedy and robust FMD serology assay.