Viral load and histological distribution of atypical porcine pestivirus in different tissues of naturally infected piglets

A newly identified atypical porcine pestivirus (APPV) associated with congenital tremors in newborn piglets has been shown to have a worldwide geographic distribution. In view of the function of E^rns in pestivirus infection and replication, the viral load and histological distribution of APPV in different tissues of naturally infected piglets were analyzed by quantitative RT-PCR and immunohistochemical detection using E^rns as the target. The results showed that the viral copy number was higher in the cerebellum, submandibular lymph nodes, and thymus than in other tissues, indicating that these are important target organs of APPV. The histological distribution of APPV was mainly in the matrix and nerve fiber in nervous tissues, endothelial cells in lymphoid tissues, and epithelial cells in other tissues, suggesting that these cells were target cells of APPV. The results will provide basic data for elucidating the pathogenesis and deepening the understanding of this newly discovered pathogen.