Respiratory disease in growing pigs after Porcine rubulavirus experimental infection.

The aim of this study was to analyze the pathogenicity and distribution of Porcine rubulavirus (PorPV) in the respiratory tract of experimentally infected pigs. Nine 6-week-old pigs were infected with PorPV and examined clinically. Blood, nasal swab, and tissue samples were collected on different days post-infection (DPI). The humoral immune responses and viral loads were evaluated. The infected pigs exhibited an increase in the respiratory clinical signs. In addition, the excretion of PorPV was extended to 23 DPI in the nasal fluid. The distribution of PorPV in the respiratory tract tissues was extended until the end of the experiment; soft palate tonsil and lymph nodes exhibited high viral loads. The major microscopic lesions observed in the lungs corresponded to interstitial pneumonia and hyperplasia of the associated lymphoid tissue. In conclusion, PorPV infection causes a pneumonic disease characterized by a prolonged virus excretion and high viral load in the lymphoid tissues.