Comparative Study of ELISA and AGID for the Detection of Antibodies Against Rabbit Haemorrhagic Disease Virus

Abstract

Rabbit haemorrhagic disease (RHD) is a disease of Oryctolagus cuniculus produced by a calicivirus (RHDV), that is highly contagious with acute evolution, high morbidity and mortality. The absence of “gold standard” method for the international trade with rabbits, strenghten veterinary laboratories to use different methods and protocols with variable values of confidence. This paper aim to evaluate the results of three serological methods designed to detect RHDV antibodies in rabbit sera: competitive enzyme-linked immunosorbent assay (cELISA), Isotype ELISA and agar gel immunodiffusion test (AGID). They were used 10 blood samples from rabbits, from different geographical area, without history of immunisation and 10 blood samples from rabbits previously immunised. Competitive ELISA (identifying the total anti-RHDV antibodies) and Isotype ELISA (identifying the IgA, IgM and IgG anti-RHDV) have been performed according with Manual of Diagnostic Tests and Vaccines for Terrestrial Animals recomandations. AGID (identifying the total anti-RHDV antibodies, but mainly IgG isotype) assay has been originaly developed during this study and has been done with two different antigen concentrations. The results were similar for all three methods, but the sensitivity of AGID was lower than both ELISA methods. Isotype ELISA allowed simultaneous differentiation and titration of IgA, IgG and IgG. For AGID, still need works in order to balance the assay.