Porcine circovirus type 3 (PCV3) is a novel member of the genus Circovirus, first detected in the United States in 2016, with subsequent reports in many countries. PCV3 infections have caused serious economic losses in the pig industry. Alternative rapid and sensitive assays for PCV3 detection are needed for clinical diagnosis, especially in laboratories not equipped with more sophisticated equipment. Here, a real-time recombinase-aided amplification assay (RAA) was developed for PCV3 detection. Specific primers and probes targeting the conserved region of the capsid gene of PCV3 were designed. The assay was performed at 39 °C for 30 min using specialized equipment. Furthermore, 36 clinical samples were used to evaluate the RAA. The analytical sensitivity of the RAA for PCV3 was 38 copies per reaction at 95% probability level, using a probit regression model. There was no cross-reactivity with other DNA viruses belonging to the Circoviridae and Parvoviridae families. The detection rate agreed with that obtained by an established real-time PCR assay with a kappa value of 1.0. Our results demonstrated that this new RAA could be used for the rapid, accurate, and sensitive detection of PCV3.

猪圆环病毒3型（PCV3）是圆环病毒属的一种新成员，于2016年在美国首次发现，随后许多国家都有报道。 PCV3感染给养猪业造成了严重的经济损失。临床诊断需要替代性快速、灵敏的 PCV3 检测方法，特别是在没有配备更先进设备的实验室中。在此，开发了一种用于 PCV3 检测的实时重组酶辅助扩增测定 (RAA)。设计了针对PCV3衣壳基因保守区域的特异性引物和探针。使用专用设备在 39°C 下进行测定 30 分钟。此外，还使用了 36 个临床样本来评估 RAA。使用概率回归模型，RAA 对 PCV3 的分析灵敏度为每个反应 38 个拷贝，概率水平为 95%。与属于圆环病毒科和细小病毒科的其他 DNA 病毒没有交叉反应。检测率与已建立的实时 PCR 检测结果一致，kappa 值为 1.0。我们的结果表明，这种新的 RAA 可用于快速、准确、灵敏地检测 PCV3。