New Zealanders should be worried about the global spread of Monkeypox, an epidemiologist says.

Monkeypox virus particles, illustration. Monkeypox is a zoonotic virus from the Poxviridae family that causes monkeypox, a pox-like disease. At the centre of the monkeypox virus is a core nucleoprotein that contains the DNA (deoxyribonucleic acid) genome. This is surrounded by an outer envelope that is covered with surface tubules. This virus, which is found near rainforests in Central and West Africa causes disease in humans and monkeys, although its natural hosts are rodents. It is capable of human to human transmission. In humans it causes fever, swollen glands and a rash of fluid-filled blisters.Photo: NOBEASTSOFIERCE/SCIENCE PHOTO LI

The head of the World Health Organisation has declared the outbreak an international public health emergency.

University of Canterbury epidemiologist Arindam Basu said cases could emerge after New Zealand’s border reopens next month.

“This is not just a disease of homosexuals or men having sex with men, it used to be, but it is not anymore. Children as young as 7 months are being infected, and women definitely, it’s spreading.”

Genomic surveillance of Monkeypox is going to be more complex than Covid-19 because of the nature of the virus, he said.

New Zealand has confirmed two cases.