Comparison of serological tests used in three state veterinary laboratories to identify maedi-visna virus infection

Three immunoassays used in Dutch, Belgian and British state veterinary laboratories for the detection of antibodies to maedi-visna virus were compared. These were an indirect enzyme-linked immunosorbent assay (ELISA), an indirect immunofluorescence test (IIFT) and an agar gel immunodiffusion test (AGIDT). The results indicated that all three assays were of similar sensitivity and specificity with identical results being recorded for 91 of 100 samples. The results of the ELISA and the AGIDT produced the closest correlation with agreement in 97 of 100 samples. With the IIFT and the AGIDT there was agreement in 94 of 100 samples and with the ELISA and the IIFT in 91 of 100 samples.