Porcine Circovirus Type 2 Infection in a Piglet Born from a Surrogate Mother

A 4-week-old male piglet being maintained in a research facility was found dead without any previous clinical signs. The piglet had been born from a surrogate mother after somatic nuclear transfer as part of a xenotransplantation study. Ovaries for nuclear transfer were obtained from a private farm outside the research facility. Histopathologically, multifocal to coalescing granulomatous myocarditis was observed in the heart, characterized by infiltration of lymphocytes, macrophages and multinucleated giant cells, and by myocardial necrosis and fibrosis. Lymphoid tissues showed marked lymphoid depletion with infiltration by histiocytes or giant cells. Immunohistochemistry showed PCV-2 antigens in necrotic myocytes, macrophages and multinucleated giant cells in the heart, as well as in macrophages and giant cells in lymphoid depleted areas of lymphoid tissues. Reproductive failure associated with PCV-2 in aborted or stillborn piglets is frequently characterized by myocarditis, and similar lesions were observed in this 4-week-old piglet with PCV-2 infection. The PCV-2 infection in this piglet may have been due to contamination or infection of an ovary from the pig farm.