Monkeypox is a virus that originates in wild animals like rodents and primates, and occasionally jumps to people. Most human cases have been in central and west Africa

The illness was first identified by scientists in 1958 when there were two outbreaks of a “pox-like” disease in research monkeys — thus the name monkeypox

Most patients only experience 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

Monkeypox can be fatal for up to one in 10 people and is thought to be more severe in children.

The World Health Organization estimates there are thousands of monkeypox infections in about a dozen African countries every year

It's the first time monkeypox appears to be spreading among people who didn't travel to Africa

In Europe, infections have been reported in Britain, Italy, Portugal, Spain and Sweden. Most of the cases involve men who have had sex with men

Britain's Health Security Agency said its cases are not all connected, suggesting that there are multiple chains of transmission happening

On Wednesday, U.S. officials reported one case of monkeypox in a man who had recently traveled to Canada