[Skip to Navigation]
December 25, 1972

Is Monkeypox a Reservoir of Smallpox?

JAMA. 1972;222(13):1645-1646. doi:10.1001/jama.1972.03210130037013

Monkeypox is no monkey business. Monkeypox may sound funny; however, it is a serious widespread disease affecting subhuman primates. Suddenly during the late 1950s, human patients with illness virtually indistinguishable from smallpox were discovered and it was proved that the infecting agent was monkeypox virus.

Monkeypox virus was first identified in 1958 in Copenhagen during an outbreak of vesicular disease among captive primates. Further outbreaks among monkeys and apes, mainly in captivity, in Europe and in North America have proved that the disease is quite common to these primates and that it may be a problem in concentrations of animals not only in the wilderness but also in captivity.

The monkeypox virus is closely related to variola and vaccinia viruses. Morphologically, it is almost indistinguishable from the variola virus. However, the immunological reactions with this virus are very different from those of variola. Also, humans who had been ill with