China announced on Friday it would begin screening people and goods entering the country for mpox over the next six months, just two days after the World Health Organization (WHO) declared the virus a global health emergency.

People travelling from countries where virus outbreaks have occurred, who have been in contact with mpox cases or display symptoms, should "take the initiative to declare to customs when entering the country", China's customs administration said in a statement.

Vehicles, containers and items from areas with mpox cases should also be sanitised, the statement added.

Sweden on Thursday announced the first case outside Africa of a more dangerous variant of mpox, with the WHO warning that further imported cases of this new strain in Europe was likely.

The WHO on Wednesday had sounded its highest possible alarm over the worsening mpox situation in Africa, calling it a global public health emergency.

Just a day before, the African Union's health watchdog declared its own public health emergency over the intensifying outbreak.

Mpox has swept through the Democratic Republic of Congo, where the virus was first discovered in humans in 1970, and spread to other countries.

Mpox is an infectious disease caused by a virus transmitted to humans by infected animals, but can also be passed from human to human through close physical contact.

It causes fever, muscular aches and large boil-like skin lesions. (AFP)