Big monkeypox cluster probably spread by sexual contact, Minister says

Health officials are preparing for a possible monkeypox outbreak in New Zealand.

But the disease is unlikely to spawn a major local epidemic and many infected people get better without treatment, Associate Minister of Health Ayesha Verrall said.

The disease has been detected in 12 countries where the virus is not endemic, the World Health Organisation said.

The virus has been spreading in North America, Europe and Australia.

Associate Health Minister Dr Ayesha Verrall says local health officials have been in touch with peers overseas about monkeypox. Photo / Mark Mitchell

The US Centers for Disease Control and Prevention said in humans, monkeypox symptoms were similar to but milder than smallpox symptoms.

Infected people might initially experience fever, headache, muscle aches, and exhaustion.

Dorsal surfaces of the hands of a monkeypox patient, showing a rash during the recuperative stage. Photo / CDC via AP

But monkeypox also caused lymph nodes to swell.

The CDC said incubation - from infection to symptoms - usually lasted one week to a fortnight but could be as short as five days and as long as three weeks.

Belgium has introduced a compulsory three-week quarantine for anyone infected with monkeypox.

"We certainly have to be prepared for the scenario because it has been in other Western countries," Verrall said.

She said monkeypox lesions were distinctive but the disease could incubate undetected at first.

"It can be transmitted by close physical contact or by droplets...But the suspicion is that the cluster that's emerging in Europe has been spread by sexual contact," Verrall said.

She said the Ministry of Health had been in contact with health officials overseas, including in Australia.

Verrall said the ministry had established an incident management team for monkeypox.

That team could help progress the next part of the plan to tackle the disease if monkeypox arrived in New Zealand.

"We have an approach called having notifiable diseases under the Health Act...Measles is an example of one.

"If you're a doctor who's diagnosed measles, you don't just treat the patient. You have obligations to report that to the Ministry of Health."

Health officers use thermal head checks to detect monkeypox on arriving passengers at Soekarno-Hatta International Airport in Tangerang near Jakarta, Indonesia. Photo / Getty Images

Although Verrall said nobody could rule out monkeypox's arrival in New Zealand, the disease did not usually lead to sustained large outbreaks.

"There is an antiviral developed but most monkeypox cases in the world recover without treatment, to be honest. It's not a severe disease."

The WHO said vaccination against smallpox was shown to be protective against monkeypox.

One vaccine and one specific treatment were approved for monkeypox but these countermeasures were not yet widely available, the WHO added.

The CDC said in Africa, monkeypox could be fatal for as many as one in 10 people who contracted the disease.