Monkeypox cases have tripled in Europe in the past two weeks, the World Health Organization (WHO) says, as it urges countries in the region to do more to ensure the previously rare disease does not become entrenched on the continent. 

In Africa, health authorities said they were treating the expanding outbreak as an emergency, calling on rich countries to share limited supplies of vaccines to avoid equity problems seen during the COVID-19 pandemic.

WHO Europe chief Hans Kluge said on Friday (local time) that increased efforts were needed despite the UN health agency's decision last week that the escalating outbreak did not yet warrant being declared a global health emergency.

"Urgent and coordinated action is imperative if we are to turn a corner in the race to reverse the ongoing spread of this disease," Dr Kluge said.

To date, more than 5,000 monkeypox cases have been reported from 51 countries worldwide that don't normally report the disease, according to the US Centres for Disease Control and Prevention.

Dr Kluge said the number of infections in Europe represented about 90 per cent of the global total, with 31 countries in the WHO's European region having identified cases.

Scramble for vaccines sees Africa left behind

Dr Kluge also said the procurement of vaccines "must apply the principles of equity".

The main vaccine being used against monkeypox was originally developed for smallpox and the European Medicines Agency said this week it was beginning to evaluate whether it should be authorised for monkeypox.

The WHO has said supplies of the vaccine, made by Bavarian Nordic, were extremely limited.

Countries including the UK and Germany have already begun vaccinating people at high risk of monkeypox; the UK recently widened its immunisation program to mostly gay and bisexual men who have multiple sexual partners and are thought to be most vulnerable.

Until May, monkeypox had never been known to cause large outbreaks beyond parts of central and west Africa, where it had been infecting people for decades, was endemic in several countries and mostly caused limited outbreaks when it jumped to people from infected wild animals.

To date, there have been about 1,800 suspected monkeypox cases in Africa, including more than 70 deaths, but only 109 have been lab-confirmed.

The lack of laboratory diagnosis and weak surveillance means many cases go undetected.

"This particular outbreak for us means an emergency," said Ahmed Ogwell, the acting director of the Africa Centres for Disease Control.

WHO says monkeypox has spread to African countries where it hasn't previously been seen, including South Africa, Ghana and Morocco.

Vaccines have never been used to stop monkeypox outbreaks in Africa, with officials relying mostly on contact tracing and isolation.

The WHO noted that similar to the scramble last year for COVID-19 vaccines, countries with supplies of vaccines for monkeypox were not yet sharing them with Africa.

"We do not have any donations that have been offered to [poorer] countries," said Fiona Braka, who heads the WHO emergency response team in Africa.

"We know that those countries that have some stocks, they are mainly reserving them for their own populations."

Disease spreading among homosexual men in UK

Dr Kluge said data reported to the WHO showed that 99 per cent of cases had been in men — the majority in men that have sex with men.

But he said there were now "small numbers" of cases among household contacts, including children.

Dr Kluge said the problem of stigmatisation in some countries might make some people wary of seeking health care and said the WHO was working with partners including organisers of gay pride events.

In the UK, which has the biggest monkeypox outbreak beyond Africa, officials noted the disease was spreading in "defined sexual networks of gay, bisexual, or men who have sex with men".

British health authorities said there were no signs suggesting sustained transmission beyond those populations.

Ahead of gay pride events in the UK this weekend, London's top public health doctor asked people with symptoms of monkeypox, like swollen glands or blisters, to stay home.

Nevertheless, in Africa the WHO says that according to detailed data from Ghana, monkeypox cases were almost evenly split between men and women, and no spread has been detected among men who have sex with men.

People with monkeypox often experience symptoms like rash, fever, fatigue, muscle pain, vomiting and chills. Most recover within weeks without needing medical care.