Passengers who were on a flight with a person who now has Covid-19 coronavirus in New Zealand will not be tested for the virus, unless they display symptoms.

The Director-General of Health, Dr Ashley Bloomfield, said people who may have been in contact with the Covid-19 patient are now being traced, in particular passengers who were on board Bali flight EK450 which the patient was on and which arrived at 5.30am on Wednesday 26 February.

Dr Bloomfield said they want to trace everyone anyone who sat two rows in front and two rows behind the passenger who tested positive for Covid-19 and they are using three sources of information to contact them.

A number of people on the flight have already called Healthline and some of them were in the relevant rows, the Auckland Regional Public Health service also has the flight manifesto and the passenger arrival cards, he said.

He said they are now well underway to tracing the people who were around the seats of this case.

"Those people who have been identified as sitting in those rows will be required to undertake 14 days of self-isolation from the time the flight arrived."

People not in those rows do not need to take any precautions unless they become unwell or have symptoms suggestive of Covid-19, he said.

Dr Bloomfield said although it was the first case of Covid-19, the chance of a community outbreak was still assessed as being low and it is an isolated case.

"We do expect further sporadic cases as we have seen in Australia, but also as we have seen across the Tasman, with proper public health interventions those cases can be well managed and with contact tracing any further community spread can be prevented," he said.

"This particular case is a very well confined and well managed situation and the number of contacts is small."

Dr Bloomfield said they had prepared for and were ready for the first positive Covid-19 test and that "individual is stable and continuing to improve in Auckland Hospital".

The Ministry of Health says there are 10 test results currently pending.

Public health campaign

A public awareness campaign about how to protect yourself from respiratory infections is now underway on the radio and in social media.

It reinforces key messages such as washing and drying your hands properly can prevent viruses from spreading, Dr Bloomfield said.

The Ministry of Health's website provides the key necessary information, he said.