Comparative Evaluation of Three Commercial ELISA Kits for Detection of Antibodies to a Nonstructural Protein of Foot-and-Mouth Disease Virus

In this study, we validated three commercial ELISA (NSP-ELISA) kits that detect antibodies to a nonstructural protein of foot-and-mouth disease virus (FMDV) in terms of their specificities and sensitivities. Although the specificities of the NSP-ELISA kits were as high as that of liquid-phase blocking ELISA (LPBE) in non-infected, non-vaccinated animals, the sensitivities of the NSP-ELISA kits were significantly lower than those of the present LPBE and did not agree with the findings of a previous report on infected animals in the field. Therefore, although countries can adopt both a "vaccination-to-kill" policy and a "vaccination-to-live" policy after emergency vaccination during an FMD epidemic, the NSP-ELISA kits do not seem to be suitable for the latter policy in Japan. These results should be useful for choosing appropriate control measures for potential future FMD epidemics in Japan and elsewhere.