Monkeypox can cause infection in humans and produce a disease similar to smallpox. This virus was first isolated in 1958 from captive monkeys in Copenhagen. First human infection with this virus was described in the early 1970s.
Cases of monkeypox have been described as a rare zoonotic infection in West and Central Africa, especially in Zaire. The subsequent cases of monkeypox were reported in North America in 2003. The origin of the infection was traced to exotic rodents imported from Africa. Monkeypox infection is acquired by handling infected animals, such as monkeys and squirrels. Person-to-person transmission is unusual.
Clinically, monkeypox cannot be distinguished from smallpox. The condition manifests with development of a generalized pustule, rash, fever, and toxemia. Electron micros-copy is useful to demonstrate the virion particles in clinical spec-imens for diagnosis of the condition.