The monkeypox virus is the causative agent of the infectious disease of monkeypox. The virus is a member of the Orthopoxvirus genus in the family Poxviridae. And its genome of is a double-stranded DNA. The disease caused by the virus is similar to but milder than smallpox and its mortality is often much lower. Humans and animals are both hosts for monkeypox virus and both species are vulnerable to the virus and may develop diseases. Monkeypox virus is mainly distributed in rainforests of west and central Africa. Isolates from Central Africa and Western Africa is different in virulence and the former is more virulent than the latter. The virus could spread in animals and humans and direct contact with the body fluid of an infected animal or being bitten may infect the virus.