Immunohistochemical detection of antigen in lamb tissues naturally infected with sheeppox virus.

The present study describes the detection of sheeppox virus antigen in various lamb tissues, using an immunohistochemical technique, in sheeppox cases which occurred naturally. Sheeppox viral antigen was detected in the cytoplasm of sheeppox cells and degenerated epithelial cells of the skin, lungs and digestive tract involving typical sheeppox lesions. Nuclear staining was also observed in some typically deformed nuclei of sheeppox cells. The immunostaining of sheeppox virus showed a correlation with the presence of sheeppox cells and degenerated epithelial cells resembling them. Additionally, in order to confirm the presence of sheeppox virus in the skin and lung samples, direct electron microscopy was performed and sheeppox virus was only demonstrated in two skin samples.