He had no information about the location of the individual, but said contact tracing had begun to find those who may have come in contact with them.

"The health response that we have had kicking in with each of these cases has been thorough and that has been aided by that early investment we made in doing things in a certain way."

Among the measures New Zealand has taken is to bar people travelling from or through China and Iran into the country. Kiwi citizens and permanent citizens can return, however. People coming to New Zealand from northern Italy and South Korea, where cases have surged, must self-isolate when they come into the country.

After the second case was confirmed, the Ministry of Health said it was still confident that the chance of widespread community outbreak was low.

Dr Clark said "day-by-day" we are seeing developments around the world.

"As we see other countries that we are in frequent contact with develop more and more cases, we are alert to the fact that that will mean we will likely get more cases arrive at our border.

"At this stage, and we have a very clearly developed pandemic plan, we are at the keep it out stage, and where we do have those sporadic incursions, in the containment phase, but the pandemic plan has all of the phases laid out, and if the medical advice, if the doctors say we need to move to a different phase, we will listen to that and we will, of course, act accordingly."

Details of second case questioned

The woman confirmed to have the virus on Wednesday recently visited northern Italy. After returning to New Zealand, prior to the self-isolation rule coming in, she flew to and from Palmerston North. Since being diagnosed, the woman has been in self-isolation in her home.

The flight the woman took back to New Zealand was last Tuesday, on 25 February. She also took two domestic flights on Monday, 2 March - NZ5103 Auckland to Palmerston North and NZ8114 Palmerston North to Auckland.

People in close contact are considered to be those who were in the same row of seats, the two rows in front and the two rows behind the infected person.

Dr Clark said officials are making "very good progress" in contacting those on the flight.

Officials are also contacting two medical centres where the woman sought advice and treatment to determine if there is any risk to staff or other people who may have been there at that time.

Dr Clark told The AM Show that those who had been in close contact with the woman were being sought. He said it was important to remember close contacts are people who had been within one metre of the individual for more than 15 minutes.

"It's passed by droplet spread. Somebody has to kinda sneeze on you or cough on you, or be up close and personal for quite a period of time for it to spread," he said.

"Nonetheless, they are very cautious, the public health people, as you would hope. They look to that wider circle and see if there any people at risk that need to be followed up on."

COVID-19 can, however, be contracted by touching surfaces where the illness is present, according to the World Health Organisation. The length of time the virus stays alive on surfaces is unknown at this stage, but some viruses can remain active for days.

The AM Show host Duncan Garner questioned the Minister over whether the newly infected person was a medical professional. Dr Clark said he wasn't aware of that being the case and expected he would have been briefed if it had been.

Garner also asked if any doctor who came in contact with the Auckland woman who was confirmed to be infected on Wednesday had been put into quarantine and if they had seen any patients since.

"Those are exactly the questions the public health officials would have been working on yesterday," Dr Clark responded.

More specifically, Garner asked if the doctor at the first medical centre the infected woman visited had been self-isolated.

"I expect all of the appropriate measures will have been taken by now," said Dr Clark.

"I cannot supervise the hundreds and hundreds of individual staff running around. I do get full briefings on areas of concern and developing situations."

If the Minister received full briefings, why didn't he know the location of that doctor, Garner said.

"I can seek that advice, but I am very confident that public health staff would have been very early to contact that person."

Dr Clark said the "appropriate actions" would have also been taken with the doctor at the second medical centre the woman visited.

"As soon as the case is confirmed, the public health officials move as quickly as they can."

At this stage, the woman does not require hospital-level care, and the World Health Organisation has pointed out that self-isolation at home is an appropriate response for those who display mild to moderate symptoms.

The infected woman has children who attend Westlake Boys and Westlake Girls High in Auckland, and both of the schools have been contacted and are on alert.

The children who attend those two schools are not showing symptoms, however, and are now at home and in isolation. They did not travel to Italy and are both well and are being monitored.

The first case of coronavirus in New Zealand was confirmed on Friday last week. That individual was a New Zealand citizen who had returned to the country from Iran, via Bali. They are currently in a stable condition, according to officials.

Spread of coronavirus

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.

More than 93,000 people worldwide have been infected, with nearly 3200 deaths.

"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, which is believed to have come from a marketplace in Wuhan. The Chinese city has become a ghost town with thousands of people there contracting the disease and many dying from it.

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 symptons or concerns.