BLOCKING ELISAS FOR THE DISTINCTION BETWEEN ANTIBODIES AGAINST EUROPEAN AND AMERICAN STRAINS OF PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS

A double blocking ELISA was developed in order to satisfy the need for large scale serological screening for PRRS and simultaneous distincti on between infection with European and American strains of PRRSV in pi g herds. The Immunoperoxidase monolayer assay (IPMA) and the double bl ocking ELISA enabled distinction on serological basis between infectio n with European and American strains of PRRSV. The distinction was pos sible from about day 7 after infection of pigs with PRRSV. The double blocking ELISA enabled the distinction at later stages of infection co mpared to the IPMA, irrespective of the strain involved. (C) 1998 Else vier Science B.V.