The World Health Organization (WHO) says the expanding monkeypox outbreak in more than 70 countries is an "extraordinary" situation that now qualifies as a global emergency.
The WHO's highest level of alert is a declaration that could spur further investment in treatment of the once-rare disease and intensify the scramble for scarce vaccines.
WHO director-general Tedros Adhanom Ghebreyesus made the decision on calling monkeypox a global emergency despite a lack of consensus among experts on the UN health agency's emergency committee, saying he acted as "a tie breaker".
It is the first time a UN health agency chief has unilaterally made such a decision without an expert recommendation.
"We have an outbreak that has spread around the world rapidly through new modes of transmission about which we understand too little," the UN chief said.
"I know this has not been an easy or straightforward process and that there are divergent views."
World must take outbreaks seriously
WHO emergencies chief Michael Ryan said the director-general declared monkeypox a global emergency to ensure the world took the current outbreaks seriously.
Although monkeypox has been established in parts of central and west Africa for decades, it was not known to spark large outbreaks beyond the continent or to spread widely among people until May, when authorities detected dozens of epidemics in Europe, North America and elsewhere.
Last month, WHO's expert committee said the monkeypox outbreak did not yet amount to an international emergency, but the panel convened this week to re-evaluate the situation.
Declaring a global emergency means the monkeypox outbreak is an "extraordinary event" that could spill over into more countries and requires a coordinated global response.
WHO previously declared emergencies for public health crises such as the COVID-19 pandemic, the 2014 West African Ebola outbreak and the Zika virus in Latin America in 2016.
The emergency declaration mostly serves as a plea to draw more global resources and attention to an outbreak.
Past announcements had a mixed impact, given that the UN health agency is largely powerless in getting countries to act.
According to the US Centers for Disease Control and Prevention, more than 16,000 cases of monkeypox have been reported in 74 countries since May.
The disease was first reported in Australia on May 20. Since then, dozens of cases have been reported across the country.
To date, monkeypox deaths have been reported only in Africa, where a more dangerous version of the virus is spreading, mainly in Nigeria and Congo.
In Africa, monkeypox mainly spreads to people from infected wild animals like rodents, in limited outbreaks that typically have not crossed borders.
In Europe, North America and elsewhere, however, monkeypox is spreading among people with no links to animals or recent travel to Africa.
WHO's top monkeypox expert Dr Rosamund Lewis said last week that 99 per cent of all the monkeypox cases beyond Africa were in men and that of those, 98 per cent involved men who have sex with men.
Experts suspect the monkeypox outbreaks in Europe and North America were spread via sex at two raves in Belgium and Spain.
Britain recently downgraded its assessment of monkeypox after seeing no signs of widespread transmission beyond men who are gay, bisexual or have sex with other men and noting the disease did not spread easily or cause severe illness.
But Mr Tedros warned "discrimination can be as dangerous as any virus" and called on civil society organisations to work with the WHO in dispelling any stigma around the virus.
The US Centers for Disease Control and Prevention said it was "supportive" of WHO's emergency declaration and hoped it would galvanise international action to stamp out outbreaks.
The US has reported more than 2,800 monkeypox cases and sent more than 370,000 vaccine doses to US states reporting cases.
Some experts had questioned whether such a declaration would help, arguing the disease was not severe enough to warrant the attention and that rich countries battling monkeypox already had the funds to do so.
Most people recover without needing medical attention, although the lesions may be painful.
Michael Head, a senior research fellow in global health at Southampton University, said WHO's emergency declaration could help donors like the World Bank make funds available to stop the outbreaks both in the West and in Africa.
Mr Tedros called for the world to "act together in solidarity" regarding the distribution of treatments, tests and vaccines for monkeypox.
AP