Figure 1.

Detection of porcine parvovirus 2 (PPV2) nucleic acid in the lungs obtained from porcine respiratory disease complex-affected pigs by in situ hybridization (ISH, ×40). The ISH signals of PPV2 ranged from a focal single individual cell (A) to multifocal (B,C) to diffuse (D,E). No signal was detected in a tissue core obtained from a PPV2 qPCR-negative case (F). Note that the signals of PPV2 were mainly detected in the pulmonary interstitium and activated lymphoid follicles (asterisk) in peribronchial lymphoid tissues (E).