DETECTION OF RAINBOW-TROUT ANTIBODIES TO INFECTIOUS PANCREATIC NECROSIS VIRUS BY AN IMMUNOASSAY

An enzyme-linked immunosorbent assay (ELISA) for the detection of infe ctious pancreatic necrosis virus (IPNV) antibodies in rainbow trout On corhynchus mykiss was assessed. There was close agreement between the results of the ELISA and a neutralisation test for detecting IPNV anti body when fish sera were tested by both methods. The differences betwe en the ELISA and virus neutralisation are most likely because antibodi es against different virus epitopes reacted in the 2 techniques. The s ample correlation coefficients of ELISA absorbance values and neutrali sation titres for 2 different populations of fish were -0.42 and 0.78. Reasons for those differences are discussed. Combined data from 4 dif ferent IPNV positive fish groups showed that virus was isolated from 2 9.9 % (32/107) of the fish, whereas more than twice that number were a ntibody positive by the ELISA. All the virus positive fish were also a ntibody positive by the ELISA and/or neutralisation. Although the ELIS A did not detect all virus positive individuals, it potentially has a role in detecting rainbow trout populations previously exposed to IPNV .