Cowpox with severe generalized eruption, Finland.

Cowpox with a severe, generalized eruption was diagnosed in an atopic 4-year-old girl by electron microscopy, virus isolation, polymerase chain reaction, and immunoglobulin (Ig) M and low-avidity IgG antibodies. The hemagglutinin gene of the isolate clustered with a Russian cowpox virus strain, and more distantly, with other cowpox and vaccinia virus strains. The patient's dog had orthopoxvirus-specific antibodies, indicating a possible transmission route. In Finnish wild rodents, orthopoxvirus seroprevalences were 0%-92%, in humans the seroprevalence was 100% in the age group >50, decreasing towards younger age groups.