EVALUATION OF AN INDIRECT ELISA METHOD FOR THE DETECTION OF CHICKEN ANTIBODIES AGAINST INFECTIOUS-BRONCHITIS VIRUS

An indirect ELISA method was developed and applied to detect antibodie s against infectious bronchitis virus (IBV). Three hundred serum sampl es collected from vaccinated and non-vaccinated chickens under field c onditions were tested. The ELISA results were compared with antibody t iters determined by a serum neutralization assay (SN). Good coefficien ts of correlation (r(2)=0.750) and of agreement (80%) were recorded an d the ELISA reproducibility was high. The cutoff point between those t echniques corresponded to ELISA level 2. It is concluded that our indi rect ELISA method can advantageously replace the conventional SN test, allowing a good follow-up of IBV post-vaccination antibodies due to i ts convenience and applicability compared to the other assay