There is a high chance that deadly coronavirus will make it to New Zealand, but health officials are confident they can prevent an outbreak.

Director-General of Health Dr Ashley Bloomfield and Director of Public Health Dr Caroline McElnay briefed media in Wellington about the risk of the virus arriving.

"At this stage we don't have any cases. There is a high likelihood we will."

Dr Bloomfield said cases in New Zealand of the new outbreak, which has killed 56 people and infect thousands overseas, were likely. 

He said there was a low to middling chance that the virus would spread once it was in New Zealand and low chance there would be an outbreak on the scale of measles.

This assessment was based on growing number of countries that had reported cases of the disease, including Australia.

"The likelihood of us getting a case is high and it may well be, as in Australia, that the person that is subsequently diagnosed had travelled and was asymptotic but developed symptoms a few days later. We may find ourselves in a similar situation."

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He said hospitals ICU units were already stepping up in preparation for the possibility of severely ill people with the virus. This was because while the virus was unlikely to kill anyone in New Zealand, figures out of China show about one-in-five people who were infected became severely ill.

Dr Bloomfield said there were about 2000 passengers a day inbound from China at New Zealand airports and they would continue to be checked by public health officials.

The ministry was also considering expanding its airport check to incoming flights from Australia that may have patients who had travelled from China. This would drastically increase the scale of public health operation.

However, because people could be infectious despite showing no symptoms while passing through airports, it would be just as important to monitor patients in the community, he said.

The ministry has asked cabinet to make also the virus a notified disease in a meeting tomorrow. This would give public health officers the power to forcibly quarantine people suspected of infection.

Dr McElnay said the ministry did not believe these powers would be needed, but it was important to have them in place if infection spread rapidly.

Dr Bloomfield said a cross-border response group met on Friday, initially focusing on Christchurch and Auckland airports.

THREE TOURISTS CHECKED IN ROTORUA

Meanwhile, three tourists in Rotorua have been checked for the coronavirus while hundreds of passengers have been screened for symptoms as they arrived in New Zealand.

The trio was assessed at Rotorua Hospital after concerns they may have been exposed to a confirmed case of the virus on an earlier flight. 

They were part of a tour group of 19 who were assessed at the Bay of Plenty hospital on Sunday. Health services had been alerted to concerns they may have been in contact with someone infected with coronavirus on a flight to Sydney on January 20. 

The tour group arrived in Auckland on Saturday evening from Australia and then travelled to Rotorua. The group were firstly assessed by St John paramedics and then three people were taken to Rotorua Hospital's Emergency Department for further assessment.  

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While they were found to have no symptoms that would indicate infection with the virus, a range of tests were taken for processing, a statement from the Lakes District Health Board said.

Expert advice was obtained from the Ministry of Health and Infectious Disease specialists and the three patients were able to be discharged on Sunday evening to re-join their tour group. 

Toi Te Ora Public Health Medical Officer of Health, Dr Neil de Wet, said public health services were continuing to follow up and monitor the group and are currently reviewing whether any further measures are necessary.

"Symptoms of the coronavirus include fever, cough, and trouble breathing, and can appear anywhere from two to 14 days after exposure. Local public health services have been working closely with the Ministry of Health to ensure appropriate protocols are followed and any risk to the public is managed appropriately."

DHB staff were aware of the need to be vigilant for signs and symptoms of people who may present to the emergency departments with flu-like symptoms, Lakes DHB Chief Executive Nick Saville-Wood said.

"DHB staff are working closely with Toi Te Ora Public Health to keep health professionals across the Lakes district informed of the risk."

HUNDREDS SCREENED AT AIRPORTS

Auckland Regional Public Health Service director Dr William Rainger said more than 600 passengers travelling on flights into Auckland International Airport from China had been through screening by public health staff.

Four health protection officers and two public health nurses provided information to passengers on symptoms of coronavirus, he said. So far no one was displaying symptoms that required an health assessment.

Public health staff were also monitoring indirect flights that from China via Australia, he said.

On Monday, flights from China into Auckland and Christchurch were being screened. A Wellington International Airport spokeswoman said as of Monday afternoon there were no current no screening in place, but this could change if advised by health officials.

Wellington has no direct flights to China but does have connections through Australia.

The "novel" strain of Coronovirus was first detected in Chinese city of Wuhan on 31 December. Since then, it has spread to 10 countries, including Australia, killing 56 people in China and 2014 infected. 

Scientists have also confirmed that the virus can be transmitted human to human, and remained undetectable yet infectious for up to two weeks.

It has many similarities to the Sars outbreak in 2003, which resulted in cases in 19 countries and 774 deaths. Like Sars, symptoms are flu-like, and can include fever, coughing and difficulty breathing. 

Associate Professor Siouxsie Wiles, from the University of Auckland's School of Biological Sciences, said news in the past fews days of likely human to human transmission and infections had elevated the seriousness of the outbreak.

"It looks like we are on the bad side of what we would expect," she said.

"It makes it more serious because it is much more difficult to contain if you can't see the symptoms."

GLOBAL RISK 'HIGH' - WHO

On Sunday the World Health Organisation said there was a "high" global risk from the new virus, but Ministry of Health's advice is that risk of an outbreak in New Zealand remains low.

Wiles said she "would not be surprised" if there were confirmed cases in New Zealand. The priority would need to be containing the virus and preventing human to human transmission.

ESR expects to be able to test for the virus this week but in the meantime would send any samples of any suspected cases to Australia for testing.

ESR virologist Dr Erasmus Smit said no suspected cases had been tested to date. While there was a chance that New Zealand would see some cases so far, when the virus had spread outside China, it had been well contained. 

"I'm a confident we would deal with them as well as other countries have."

Wiles said the risk to New Zealand would grow if the infection spread to major Chines cities with more regular connections to New Zealand, such as Shanghai and Beijing.