The sudden surge of monkeypox cases outside Africa has alarmed public health authorities around the world. In Europe and North America it’s the first time community transmission has been recorded among people with no links to west or central Africa. So what is happening?

Ian Sample talks to virologist Oyewale Tomori about why monkeypox is flaring up, whether we should fear it, and what we can learn from countries such as Nigeria and the Democratic Republic of the Congo, which have been tackling this virus for decades.