Application and development of immunoperoxidase monolayer assay kit for detection of antibody against porcine reproductive and respiratory syndrome virus

A kit for detection of antibody against porcine reproductive and respiratory syndrome virus(PRRSV) was prepared by immunoperoxidase monolayer assay(IPMA) and assembled as PRRSV-IPMA kit.Sensitivity,specificity,repeatability and preservation of the kit were evaluated.Using the PRRSV-IPMA kit sera from PRRSV-infected pigs were detected to be 50% and 100% of positive rates at week 1 and 2 post-inoculation,respectively.The sera from control group pigs showed negative reaction.In comparison,parallel detections were done using the PRRSV-IPMA kit and the commercial PRRSV-ELISA kit from IDEXX Co.,and the agreement rate was 83.3%.The PRRSV-IPMA kit was stable for 18 months at-20℃,and didn't cross-react with the other virus reference sera.PRRSV antibodies in 520 serum samples from 13 farms of Heilongjiang,Jilin,Liaoning,Hebei and Shanghai were detected by the PRRSV-(IPMA) kit.The positive rates of four farms were more than 90%,and only two farms were negative,and 10%-57% in the rest of farms.