A public health expert believes the Government needs to do even more to prevent the spread of coronavirus.

On Monday, Prime Minister Jacinda Ardern announced that public gatherings of 500 people or more would be banned. But Professor Michael Baker, of Otago University's department of public health, says that move does not go far enough.

"We should probably be going even further at the moment with these measures," Prof

Prof Baker said the Government did the right thing with the new ban as well as its move over the weekend to force anyone coming into the country - with the exception of people arriving from the Pacific Islands - to go into self-isolation for 14 days.

"I think the entire health sector breathed a huge sigh of relief, many New Zealanders would have as well."

Eight cases of coronavirus have been confirmed in New Zealand so far, with Prof Baker saying he backs the Government's proactive approach to try and stop the virus' spread.

Anyone claiming the country was overreacting with its measures needed to think again, Prof Baker said.

"They need to get a basic lesson in mathematics. Every six day you double the number of cases - by the time you're aware of it it may be very hard to contain it."

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Around the world, more than 175,000 people have been infected with the disease, with the death toll standing at over 6700.

The World Health Organisation on Tuesday warned of a "rapid escalation" in cases, urging countries to test anyone suspected of having COVID-19.

On Monday, Prof Baker said the virus' spread was unlike anything seen in recent times.

Baker told Newshub.

"We need to look at school closures now and also even look at public transport."

"No one alive today has really been through a pandemic like this," he said, predicting that it could be another year or so until it was "business as usual" in New Zealand.

Although schools here remain open, many countries around the world have already taken the step of stopping classes in a bid to stop the virus' spread.

In Europe, the new epicentre of the outbreak, a number of countries have implemented tough border controls and urging residents to stay home and avoid any non-essential travel.