Parapoxvirus infections of reindeer and musk ox associated with unusual human infections.

This report concerns five cases of human infection resulting in lesions morphologically similar to human orf. Parapoxvirus infection in reindeer was the probable source of infection in four cases. The fifth case involved musk ox. Two of the cases involving reindeer are particularly interesting as transmission of infection occurred indirectly. Viral particles were not seen by electron microscopy of human tissues, due probably to the late stage of the illness at the time of examination. However, electron microscopy of negatively stained suspensions prepared from biopsy material collected from reindeer calves at the outbreak of the illness and of post-mortem material from the musk ox revealed characteristic parapoxvirus particles. In one patient the infection was accompanied by fever, lymphadenopathy and nausea, which cleared following a few days of treatment with doxycycline chloride. 4 cases were curetted after 4, 6, 12 and 20 weeks and healed withour scarring whereas the fifth patient was by request left alone. This resulted in localized dark pigmentation following completion of the healing process after 26 weeks.