All poxviruses belong to the family
Poxviridae
and subfamily
Chordopoxviridae
. All naturally occurring poxviruses that infect humans are sporadic zoonotic agents except the
Molluscipoxvirus
MCV, which is transmitted strictly between humans. The clinical appearance of human monkeypox, typified by that seen with the Congo Basin virus, is much like that of smallpox, with fever, a centrifugally distributed vesiculopustular rash, respiratory distress, and in some cases, death from systemic shock. In humans, cowpox lesions occur mainly on the fingers, with reddening and swelling. Human parapoxvirus infection is normally associated with an exposure to sheep, goats, and/or cattle. Electron microscopy could be a method for laboratory diagnosis of poxvirus infections. Serologic methods currently used to detect antibodies against human orthopoxviruses include enzyme‐linked immunosorbent assays, the virus neutralization test, Western blotting, and hemagglutination inhibition. The description of an orthopoxvirus immunoglobulin M assay offers great promise to enhance investigations of orthopoxvirus infection outbreaks, which are often semi‐retrospective.