Medycyna Wet. 63 (4), 455-458, 2007
Niedbalski W., Kęsy A. |
Validation of a solid-phase competition ELISA (SPCE) for measuring antibodies to foot-and-mouth disease virus |
The aim of this study was to examine the essential validation parameters of a solid-phase competition ELISA (SPCE) assay for the serological detection of foot-and-mouth disease virus (FMDV) antibody serotypes A, O and Asia 1. The sensitivity of the SPCE was calculated from the results of testing positive sera from convalescent and vaccinated cattle. The highest sensitivity of assay (>99% for all FMDV types) was found at PI 41-50 but implementation of a cut-off level above PI 50 resulted in a decrease of ELISA sensitivity. The specificity of SPCE was examined by testing 760 samples of FMDV-negative field sera collected from healthy, neither infected nor previously vaccinated cattle. In contrast to the sensitivity, an increase in ELISA specificity was observed in tested successive PI ranges and 100% was achieved at PI 61-70. The accuracy of assay was determined by the estimation of repeatability and reproducibility of results. These were performed using a panel of reference sera distributed by the World Reference Laboratory for Foot-and-Mouth Disease (WRL FMD) for the purpose of Phase XVIII collaborative studies. Repeatability and reproducibility were expressed as a coefficient of variation (CV) by analyzing the results of tested reference sera. In case of reproducibility, the CVs for 9 of 10 tested sera ranged from 6.6 to 9.8%. The results of reproducibility were more variable CVs for all reference sera were generally higher and for two samples (weak positive for FMDV serotype A) they exceeded the acceptable maximum limit. |
Keywords: foot-and-mouth disease, ELISA (SPCE) |