Feline orthopoxvirus infection transmitted from cat to human.

We report the case of a 56-year-old female patient who presented with an inflamed, ulcerated lesion on the left side of her neck after contact (scratch) with a cat living in the patient's house. Satellite lesions developed despite local treatment and parenteral clindamycin. Histopatholgic examination and the Tzanck test showed evidence of a viral infection. Subsequent transmission electron microscopy of scrap tissue and material from a fresh pustule exhibited multiple typical poxvirus particles, predominantly in remnants of scaled-off layers of degenerated keratinocytes, and virus particles in intermingled phagocytes, leading to the diagnosis of feline Orthopoxvirus (cowpox virus) infection. These results were verified by polymerase chain reaction and sequencing. Concern has been raised as to whether discontinuation of smallpox vaccine would cause an increase in Orthopoxvirus infection, but this has not yet shown to be the case.