4 answers to key questions about the monkeypox outbreak

More than 300 people in 21 countries outside Africa have been infected with the disease

A colorized electron micrograph of monkeypox infecting monkey cells

Monkeypox (orange), shown infecting monkey cells (green) in this colorized electron micrograph, has spread to multiple countries outside Africa. The large outbreak is unusual for the virus, which is transmitted by close contact.

NIAID/Flickr (CC BY 2.0)

An outbreak of monkeypox has some people worried that the world is on the brink of another pandemic.