Director-General of Health Dr Ashley Bloomfield says all people in the GA standing area should be aware of the COVId-19 symptoms. They are casual contacts, rather than close contacts.

He believes the risk is very low for all other people who attended the concert.

The man is at home in isolation alongside his wife. They returned from northern Italy last week. The woman had a return trip to Palmerston North and visited two medical centres - one being Westgate Medical Centre.

Dr Bloomfield said anyone who may have attended a medical centre and is considered to be at risk will be contacted by officials.

There have been 212 negative tests and four positive tests. Several are currently underway. One is the father of the person confirmed to have coronavirus on Thursday. The father, who recently returned from Iran, is believed to have given the illness to the man in his 40s. Even if the test comes back as negative, the father will still be considered a "probable case".

"There have also been questions around naming other places of interest linked to cases, such as employers. We would name these places if a wider public health risk was determined. In the cases to date, employers are being advised directly by local public health officials over the appropriate actions they may need to take," said Dr Bloomfield.

"The Ministries of Health and Education continue their support for students and schools linked to confirmed cases. All students identified as close contacts of confirmed cases are at home in isolation. They have no symptoms.We do not believe there is currently any risk to students or staff in any of the schools."

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 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 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, China.

PM urges concerned doctors to contact Ministry of Health

Speaking to the media in Christchurch on Friday, Prime Minister Jacinda Ardern urged any GPs with concerns over their own safety to contact the Ministry of Health.

"Part of our pandemic plan is the availability of appropriate face masks, for instance, which are useful for our medical health professionals who may be dealing with individuals who are showing symptoms," Ardern said.

"We have nine million of those masks in stock here in New Zealand so if there are any concerns there I would urge those GPs [to have] direct contact with the Ministry of Health because those pieces of equipment are certainly available."

With a number of large gatherings planned over the weekend to mark one year since the tragic Christchurch mosque shootings, Ardern also urged anyone feeling unwell to stay at home.

However, for the moment, the Government would not be taking precautionary steps such as cancelling public gatherings.

"At this stage, we haven't issued that advice for any change in those gatherings but we are constantly monitoring New Zealand's situation as well as the global situation," Ardern said.

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.