The President of the Royal New Zealand College of General Practitioners says "at least 50 percent" of New Zealand's population could become infected by the COVID-19 coronavirus.

More than 115,000 cases of the potentially deadly illness have been recorded worldwide with 4000 deaths. Some experts have estimated that billions of people could contract the disease, which has recently seen surges in countries like South Korea and Italy after originating in China.

Dr Samantha Murton, the head of the Royal New Zealand College of General Practitioners (RNZCGP) told Magic Talk's Ryan Bridge on Tuesday that estimates show half of all New Zealanders could contract the illness. 

"At the moment, what we are sort of looking at is that at least 50 percent would probably be infected. What the measures we are putting in place are trying to do is reduce the extreme nature of that, so we can get a reduced number," Dr Murton said.

"Rather than having this enormous peak of having lots of people unwell at once, we try and keep that down, so there is a reduced number being unwell at any one time and manageable within the health service we have got.

"It's an estimate, but that's what we are hearing from the epidemiologists and people like that."

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Murton said epidemiologists would be best to comment on how many people may die in New Zealand, but "the death rate is much more significant in the older population".

"For our younger people and people who don't have any other health conditions, under the age of 50 or 60, you're reasonably well and don't have too much of a major illness.

"The problem is people can be very mildly unwell and not know they've got coronavirus. That's where keeping your distance from people, washing your hands, making sure you're not going to work when you're unwell is really, really important for anyone."

She said people should follow the advice of the Ministry of Health when deciding whether to attend a large public event in the coming days.

"We certainly, from the college perspective, have postponed some of our [events], but that is because there are a whole lot of health workers that are going to be involved and they may be needed in their community so it is much more important that they are out working than being in an event that we can delay to another time.

"For other people, you just need to be careful about what you do when you go to these big events."

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A person who has COVID-19 is estimated to infect between two and four people, according to a study in the Journal of Travel Medicine. That could be enough to sustain and accelerate an outbreak if no measures are put in place to reduce the spread.

While half of New Zealanders could be infected at this rate, health officials have suggested ways to prevent the spread of the disease.

The World Health Organisation says the best way to protect yourself is to wash your hands for 20 seconds and avoid touching your face. Viruses are sensitive to detergents, meaning soap will make the virus inactive.

But if you're feeling sick the Ministry of Health asks you to "please stay at home", regardless of the severity of your illness.