The World Health Organisation has declared the Monkeypox outbreak a "public health emergency of international concern".

The maximum emergency alert came after the WHO committee gathered for a second emergency meeting, following a global surge of more 16,000 cases in 75 countries. There have also been five deaths linked to the outbreak, including three in Nigeria and two in the Central African Republic.

The Ministry of Health announced New Zealand's first case two weeks ago. And according to Australia's Department of Health and Aged Care (DHAC), there have been 41 confirmed cases in Australia as of July 19. This includes 22 in NSW, 15 in Victoria, two in the Australian Capital Territory, one in Queensland and one in South Australia.

In a media briefing early on Sunday (NZT), WHO Director-General Dr Tedros Adhanom Ghebreyesus said that while there was a "clear risk of further international spread," the "risk of interference with international traffic remains low for the moment".

"WHO's assessment is that the risk of #monkeypox is moderate globally and in all regions, except in the European region where we assess the risk as high," he said.

"We have an outbreak that has spread around the world rapidly, through new modes of transmission, about which we understand too little and which meets the criteria in the International Health Regulations."

Dr Ghebreyesus also said that the outbreak was currently "concentrated among men who have sex with men, especially those with multiple sexual partners," however he urged against "stigma and discrimination".

"That means that this is an outbreak that can be stopped with the right strategies in the right groups," he said.

"It's therefore essential that all countries work closely with communities of men who have sex with men, to design and deliver effective information and services, and to adopt measures that protect both the health, human rights and dignity of affected communities."

According to Australia's health department, the virus "typically starts with fever and swollen lymph nodes and may also include headache, muscle aches, joint pain and back pain".

Most patients will also experience rashes and lesions which can occur in one part, or the entire body. This includes the mouth, eyes and genitalia. The lesions have been described as "the blisters you see with chickenpox, but larger".

The onset of symptoms can appear anywhere between five to 21 days from infection, however symptoms typically present within seven to 14 days.

According to AP, a global emergency is WHO's highest level of alert but the designation does not necessarily mean a disease is particularly transmissible or lethal. Similar declarations were made for the Zika virus in 2016 in Latin America and the ongoing effort to eradicate polio, in addition to the COVID-19 pandemic and the 2014 Ebola outbreak in West Africa.

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 tiebreaker". It was 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," Tedros said. "I know this has not been an easy or straightforward process and that there are divergent views."

WHO emergencies chief Dr Michael Ryan said the director-general declared monkeypox a global emergency to ensure that 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 reevaluate the situation.

According to the US Centers for Disease Control and Prevention, more than 16,000 cases of monkeypox have been reported in 74 countries since about May. To date, monkeypox deaths have only been reported in Africa, where a more dangerous version of the virus is spreading, mainly in Nigeria and Congo.

In Africa, monkeypox mainly spreads to people by 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 this 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.

NZ's first case

New Zealand registered its first case of monkeypox two weeks ago.

The person is in their 30s, lives in Auckland and had recently returned from overseas travel in a country with reported cases of monkeypox, the Ministry of Health said in a statement at the time.

"Given the increase in cases internationally, including Australia, the arrival in New Zealand was not unexpected," the ministry said in a statement.

"We have already taken steps to prepare for the arrival of monkeypox. Last month monkeypox was officially listed as a notifiable disease enabling us to utilise the tools needed to contain any possible spread of the disease including isolation orders and readying contact tracing capabilities. A monkeypox PCR test is available in New Zealand labs and is what has been used to detect this first case.

"There are a very small number of contacts of the case who are being advised to watch for symptoms. There is no evidence of community transmission here."

To protect the privacy of the case and contacts, the ministry said they would not be providing additional information on them, but monitoring of the case continued.

At the time of the announcement, epidemiologist professor Michael Baker said there was no need to panic. "It's a very manageable infectious disease, nothing like Covid-19."

Baker said it was inevitable the disease would arrive here. "They've had multiple cases in Australia, it was just a matter of time before we got cases here."

Baker said some people need to be cautious. "Anyone with lesions that look like chickenpox who have been in contact with a case or have been to Africa should be wary."

Monkeypox lesions. Photo / Getty Images

In their release two weeks ago, the ministry provided public health advice for New Zealanders to prepare and deal with the emergence of the disease.

"Cases of monkeypox outside of endemic countries have primarily been identified amongst gay and bisexual men and men who have sex with men, and international cases have been clustered around events where this occurs."

The ministry is asking anyone who's been overseas and attended events connected with the spread of monkeypox, to be aware of any symptoms and seek advice from where they normally would get health advice.

Anyone who thinks they may have been exposed should either contact their GP or Healthline free on 0800 611 116, or get in touch with a sexual health clinic.

- by Barry Hatton and Maria Cheng, news.com.au