Salmonid alphavirus (SAV) is the etiological cause of pancreas disease (PD) in Atlantic salmon (Salmo salar). Several vaccines against SAV are in use, but PD still cause significant mortality and concern in European aquaculture, raising the need for optimal tools to monitor SAV immunity. To monitor and control the distribution of PD in Norway, all salmonid farms are regularly screened for SAV by RT-qPCR. While the direct detection of SAV is helpful in the early stages of infection, serological methods could bring additional information on acquired SAV immunity in the later stages. Traditionally, SAV antibodies are monitored in neutralization assays, but they are time-consuming and cumbersome, thus alternative assays are warranted. Enzyme-linked immunosorbent assays (ELISAs) have not yet been successfully used for anti-SAV antibody detection in aquaculture. We aimed to develop a bead-based immunoassay for SAV-specific antibodies. By using detergent-treated SAV particles as antigens, we detected SAV-specific antibodies in plasma collected from both a SAV challenge trial and a field outbreak of PD. Increased levels of SAV-specific antibodies were seen after most fish had become negative for viral RNA. The bead-based assay is time saving compared to virus neutralization assays, and suitable for non-lethal testing due to low sample size requirements. We conclude that the bead-based immunoassay for SAV antibody detection is a promising diagnostic tool to complement SAV screening in aquaculture.

鲑鱼鲑鱼（SAV）是大西洋鲑鱼（Salmo salar）胰腺病（PD）的病因）。目前正在使用几种抗SAV的疫苗，但是PD在欧洲水产养殖中仍引起巨大的死亡率和关注，因此需要用于监测SAV免疫力的最佳工具。为了监测和控制挪威PD的分布，通过RT-qPCR定期筛查所有鲑鱼养殖场的SAV。虽然SAV的直接检测在感染的早期阶段是有帮助的，但血清学方法可以在后期获得有关获得的SAV免疫力的更多信息。传统上，SAV抗体在中和测定中进行监测，但是它们既费时又繁琐，因此需要进行其他测定。酶联免疫吸附测定（ELISA）尚未成功用于水产养殖中的抗SAV抗体检测。我们旨在为SAV特异性抗体开发基于珠子的免疫测定法。通过使用去污剂处理的SAV颗粒作为抗原，我们在从SAV攻击试验和PD现场暴发收集的血浆中检测到SAV特异性抗体。大多数鱼类对病毒RNA呈阴性后，发现SAV特异性抗体水平增加。与病毒中和测定相比，基于珠的测定节省了时间，并且由于样品量要求低，因此适合非致命性检测。我们得出结论，基于珠的SAV抗体免疫测定是一种有前途的诊断工具，可补充水产养殖中的SAV筛选。与病毒中和测定相比，基于珠的测定节省了时间，并且由于样品量要求低，因此适合非致命性检测。我们得出结论，基于珠的SAV抗体免疫测定是一种有前途的诊断工具，可补充水产养殖中的SAV筛选。与病毒中和测定相比，基于珠的测定节省了时间，并且由于样品量要求低，因此适合非致命性检测。我们得出结论，基于珠的SAV抗体免疫测定是一种有前途的诊断工具，可补充水产养殖中的SAV筛选。