Standardisation and establishment of a rabies ELISA test in European laboratories for assessing the efficacy of oral fox vaccination campaigns.

A simple and rapid enzyme linked immunosorbent assay (ELISA) to detect rabies antibodies in field fox sera has been standardised and established in several European laboratories. The same panels of 100 coded sera were investigated by four laboratories using this ELISA assay and reference serum neutralisation techniques (fluorescent antibody virus neutralisation (FAVN) test and rapid fluorescent focus inhibition test (RFFIT)). This indirect ELISA technique is highly correlated with conventional seroneutralisation test on cell culture. Results obtained with this ELISA test provide an almost perfect agreement between laboratories while the agreement of FAVN test and RFFIT results is substantial and very satisfactory. In view of this study, this simple and rapid ELISA test is a suitable tool for evaluating the sero-conversion rate in fox populations following oral rabies vaccination campaigns in European countries.