ABSTRACT
Porcine reproductive and respiratory syndrome (PRRS) is recognized as one of the most important infectious diseases causing serious economic loss in the swine industry worldwide. Due to its increasing genetic diversity, a rapid and accurate diagnosis is critical for PRRS control. The immunochromatographic strip test (ICST) is a rapid and convenient type of immunoassay. In this study, an on-site immunochromatographic assay-based diagnostic method was developed for detection of PRRS virus (PRRSV)-specific antibodies. The method utilized colloidal gold nanoparticle-labeled dual-type nucleocapsid proteins encoded by open reading frame 7. We evaluated 991 field samples from pig farms and 66 serum samples from experimentally PRRSV-inoculated pigs. Based on true PRRSV-specific antibody-positive or