Monkeypox is a rare disease caused by infection of the virus with the same name. It was first discovered in 1958 in groups of monkeys kept for research, and the first human case was recorded in 1970. The disease is in the same family of viruses as the smallpox virus. However, it is considered to be a milder disease than smallpox albeit with similar symptoms. The first symptoms of monkeypox include a fever, headache, muscle aches, swollen lymph nodes, chills and exhaustion, according to the U.S. Centers for Disease Control and Prevention (CDC). In 2022, a global outbreak of monkeypox has seen more than 100 confirmed or suspected cases reported in several countries, including the U.S.