Development of Single Serum ELISA and Flow Through Assay for Infectious Bursal Disease of Poultry

Abstract

The infectious bursal disease (IBD) is an age-limiting viral disease of chicken affecting both broiler and layer chicks between 3 – 6 weeks of age characterized by severe immunosuppression and high mortality. The maternally derived antibodies protect chicks till they develop age – resistance, hence breeder flocks immune status monitoring regularly helps in ensuring adequate levels of maternal antibodies transfer to hatchlings and fine tuning of vaccination schedule. The conventional virus neutralization test (VNT) though gold standard, is time consuming and cumbersome. Hence, alternate immunodiagnostic tests which are simple and relatively easy to perform viz., single serum dilution enzyme linked immunosorbent assay (ELISA) for antibody titre and flow through assay (FTA) for antigen detection were developed. A standard curve was constructed by using regression analysis which helped in derivation of an equation and that allowed to demonstrate correlation between observed titre and predicted titre. At a dilution of 1:2000 of serum there was a linear relationship between predicted titres at single serum dilution and observed titre. The FTA was able to detect 200 ng / µl concentrations of IBDV. The FTA can be performed as, on spot test for detection of IBDV in suspected cases.