Serological detection of bluetongue: comparison of competitive ELISA with other routinely used immunoassays

Abstract

The performance of 2 conventional serological assays, viz. the standard agar gel immunodiffusion (AGID) and counter current immunoelectrophoresis (CCIE) was compared with commercially available competitive enzyme-linked immunosorbent assay (cELISA) for the detection of group specific bluetongue virus antibodies in sheep and goats. The comparative efficacy was evaluated on 705 sera samples from sheep and goats. Differences were observed in the relative sensitivities and specificities of the tests and seroprevalence using AGID, CCIE and cELISA. The highest seropositivity of 62.69% was obtained with cELISA followed by AGID (29.92%) and CCIE (22.14%). The relative sensitivity and specificity of AGID was 38.23 and 84.83% whereas CCIE was 28.95 and 88.59% using cELISA as the reference test. Among all the assays cELISA was highly sensitive followed by AGID and CCIE. Based on the results, it is proposed that cELISA should be preferred over other assays for the detection of antibodies against bluetongue virus.