(NEXSTAR) – Monkeypox may be the newest global outbreak concern, but the virus itself is nothing new. It was first discovered over 50 years ago in a group of captive primates – hence the name “monkeypox.”

The virus has some more scientific name designations; it Orthopoxvirus genus in the family Poxviridae, according to the World Health Organization.

In 1958, there were two outbreaks of the virus in monkey colonies that were being researched, according to the Centers for Disease Control and Prevention. It wasn’t until 1970 that the first human case of monkeypox was discovered in the Democratic Republic of the Congo, according to the CDC.

Even though the virus has been around a long time, it has not been eradicated. Because animals continue to harbor the virus, it is endemic in several parts of Africa.

Since the 1970s, most human cases have been in central and west Africa, and outbreaks have been relatively limited. The WHO estimates there are thousands of monkeypox infections in about a dozen African countries every year. Most are in Congo, which reports about 6,000 cases annually, and Nigeria, with about 3,000 cases a year.

Then, in 2022, the virus started to spread in Europe and now in the United States. Forty cases have been confirmed in 14 states and Washington, D.C., according to CDC data on Thursday.

Another cluster of U.S. cases happened back in 2003, when 47 people in six states had confirmed or probable cases. They caught the virus from pet prairie dogs that been housed near imported small mammals from Ghana.

Most monkeypox patients experience only fever, body aches, chills and fatigue. People with more serious illness may develop a rash and lesions on the face and hands that can spread to other parts of the body.

Most people recover within about two to four weeks without needing to be hospitalized, monkeypox can be fatal for up to 6% of cases and is thought to be more severe in children.

The Associated Press contributed to this report.