The World Health Organization declared that mpox no longer constitutes a global health emergency on Thursday, almost exactly a year after the disease formerly known as monkeypox started spreading globally.

WHO chief Tedros Adhanom Ghebreyesus said the decision was prompted by falling case numbers worldwide, but emphasised that the disease remains a threat, particularly in areas of Africa where it has long been present.

The announcement comes just a week after the UN agency also declared that Covid-19 no longer constitutes a public health emergency of international concern (PHEIC), its highest level of alarm.

"However, as with Covid-19, that does not mean that the work is over," Tedros told an online press conference.

"While the emergencies of mpox and Covid-19 are both over, the threat of resurgent waves remains for both. Both viruses continue to circulate and both continue to kill," Tedros said.

Though long present in parts of Central and West Africa, in May last year cases of the disease started emerging in Europe, North America then elsewhere, mostly among men who have sex with men.

The WHO declared mpox was a PHEIC in July. But the number of people infected with the disease -- which causes fever, muscular aches and large boil-like skin lesions -- has consistently fallen since.

More than 87,000 cases and 140 deaths have been reported from 111 countries during the global outbreak, according to a WHO count.

Almost 90 percent fewer cases were recorded over the last three months compared to the previous three-month period, Tedros said.

'Downward trend'

"While we welcome the downward trend of mpox cases globally, the virus continues to affect communities in all regions, including in Africa, where transmission is still not well understood," he said.

He added that cases related to travel also represented an ongoing threat.

"Mpox continues to pose significant public health challenges that needs a robust, proactive and sustainable response," he added, calling on countries to maintain surveillance and access to tests and vaccines.

Because the global cases were overwhelmingly among men who have sex with men, there were fears that discrimination would mar the response to the outbreak.

"While stigma has been a driving concern in managing this epidemic and continues to hamper access to care for mpox, the feared backlash against the most affected communities has largely not materialised," Tedros said.

"For that, we are thankful."

He also highlighted that people with untreated HIV are at particular risk from mpox.

The monkeypox virus -- which causes mpox disease -- is transmitted through close contact with infected humans or animals, as well as via materials such as contaminated sheets.

It was first discovered in humans in 1970 in the Democratic Republic of Congo. Until May last year, its spread among humans had been mainly limited to certain West and Central African nations.

After the emergency status was lifted for Covid and mpox, there is now just one WHO-declared PHEIC -- for poliovirus, which was declared in May 2014.