Of the eight new cases, two are in Southland, two in Taranaki, one in Rotorua, two in Auckland and one in Northland. Further details, including flight information, will be released later. One of the new recorded cases is currently in hospital. None of the new cases are school students.

"We are obviously alert to all these new cases and particularly identifying any close contacts so we can isolate them, and we are expecting more given the rapidly evolving situation overseas," Dr Bloomfield says.

On Saturday, the Prime Minister announced travel restrictions forcing anyone entering New Zealand from outside of the Pacific Islands to self-isolate for 14 days. Dr Bloomfield said on Thursday that those self-isolating without any symptoms should be focused on physical distancing, including not going to work or socialising. Going for a walk or a bike ride is appropriate, however.

The Director-General said efforts to stem the virus' spread would continue over "some months".

"We are preparing to take all the measures we need to ensure we don't get wider community spread that might overwhelm our health system or put people at risk," he said.

Dr Bloomfield said other countries have typically put themselves into lockdown when there was widespread community transmission. This is not yet the case in New Zealand and he dismissed rumours suggesting a lockdown is imminent.

He said that some of the initial individuals confirmed to have the virus have fully recovered, but Dr Bloomfield didn't have the exact number.

There are more than 200,000 cases worldwide, with about 8500 having died from the sickness.

On Wednesday, Dr Bloomfield revealed eight cases of the virus, taking the total at that time to 20. Those were four cases in Auckland, one in Christchurch, two in Waikato and one in Invercargill.

There have also been several cases around New Zealand of students or staff at schools requiring testing, including at Auckland's Green Bay High School and Selwyn School in Rotorua. So far, New Zealand authorities have rejected a widespread closure of schools, saying it was not yet necessary. There have also been concerns that closing schools would require their parents taking time off work during a period of economic uncertainty.

After a student at Logan Park High School in Dunedin tested positive, 150 close contacts were tested. Dr Bloomfield confirmed on Thursday that results for most of these tests have come back and they were negative. Some remain pending.

An economic package was revealed by the New Zealand Government on Tuesday to assist businesses and workers adversely affected by the disruption to trade and travel routes. It's also launched a public health campaign to attempt to spread information about the virus and how people can individually combat it.

Mass gatherings of more than 500 people can no longer go ahead, but schools are allowed to stay open.

What we know about coronavirus

Coronavirus is primarily spread through droplets in the air after someone sneezes or coughs. However, it can also be contracted by touching surfaces where the illness is present, according to the World Health Organization. The length of time the virus stays alive on surfaces is unknown at this stage, but some viruses can remain active for days.

The WHO was first informed of cases of the virus in Wuhan on December 31. It was identified as a coronavirus on January 7 and can spread through human-to-human transmission.

"Common signs of infection include respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death," the WHO says.

"Standard recommendations to prevent infection spread include regular hand washing, covering mouth and nose when coughing and sneezing, thoroughly cooking meat and eggs. Avoid close contact with anyone showing symptoms of respiratory illness such as coughing and sneezing."

There is currently no vaccine for the sickness.

How can I protect myself?

avoid touching the mouth, nose and eyes with unwashed hands

washing your hands before eating

carrying a hand sanitiser at all times

being particularly mindful of touching your face after using public transport or going to the airport

carry tissues at all times to cover the mouth and nose when coughing or sneezing (then dispose of it)

not eating shared or communal food

avoiding shaking hands, kissing cheeks

regularly cleaning and sanitise commonly used surfaces and items, such as phones and keys

avoiding close contact with people suffering from or showing symptoms of acute respiratory infection

seeking medical attention if you feel unwell.

A full explainer on protecting yourself from coronavirus can be found here.

The Ministry of Health is reminding the public to get in touch with Healthline on 0800 358 5453 if they have symptoms or concerns.