Monkeypox is a public health emergency. Here's what you need to know about the virus

This 2003 electron microscope image made available by the Centers for Disease Control and Prevention shows mature, oval-shaped monkeypox virions, left, and spherical immature virions, right, obtained from a sample of human skin associated with the 2003 prairie dog outbreak. The Biden administration has started shipping testing kits for monkeypox to commercial laboratories, in a bid to speed diagnostic tests for suspected infections for the virus that has already infected at least 142 people in the U.S.(Cynthia S. Goldsmith, Russell Regner/CDC via AP, file)

The World Health Organization has declared the monkeypox outbreak a public health emergency of international concern, but it’s not a disease that the general public has been familiar with.

As of Saturday, the virus has been discovered in more than 70 countries, 68 of which historically had not reported cases of monkeypox. In the U.S., confirmed cases have popped up in all but six states: Alaska, Maine, Mississippi, Montana, Vermont and Wyoming, according to the CDC.

For well over a decade, members of the scientific community have been concerned about the potential of a monkeypox epidemic.