Dermal Fowlpoxvirus Infection in a Sparrow Diagnosed by PCR

Multiple nodular skin lesions were found in a debilitated field sparrow. Histopathological examination on the cutaneous lesions revealed intense epidermal hyperplasia with acidophilic intracytoplasmic inclusion bodies in the ballooned keratinocytes, suggesting fowlpoxvirus (FPV) infection. Nested PCR specifically amplified a 419 bp DNA fragment of FPV 4b gene from the skin lesions, while it was not detected in other tissue samples such as liver, lung, kidney, trachea and neck. DNA sequencing of the second PCR product revealed 97.8% homology with the fragment of FPV 4b gene. These results indicate that the skin lesions were caused by infection with FPV.