A mystery virus is causing severe lung issues in the Chinese city of Wuhan, and has now been detected in two other countries in people who have travelled from Wuhan.
Microbiologist Dr Siouxsie Wiles is warning travellers who may be heading to China to remember basic hygiene practices, including washing hands properly with soap and water and drying them well, as well as practicing good sneeze hygiene.
"For people who are travelling to China the things to be aware of are avoid unnecessary contact with animals, especially in the markets and things, and again if you do touch animals make sure you wash your hands and things."
She told TVNZ1's Breakfast this morning the virus was in early stages, but it's known to be in the family of coronaviruses.
"They're certainly known in animals and in humans. The human versions cause common colds, but there have in the past been two instances where an animal corona virus has jumped into humans and caused problems."
Those two cases were of Sars and Mers, which came from camels.
Dr Wiles said the concern for the new virus was that it had clearly come from an animal, but it's not known where it's come from and how well is it transmitted between people and how many of the people who get it become severely ill.
"At the moment they're thinking it's not so well transmitted between people, but it's very very early days," she said.
"The reason they're concerned I guess is because Sars was pretty well transmitted and also pretty deadly - about 10 per cent of those people who got infected died. So what we don't want is a scenario where you've got something highly transmittable that's very, very deadly."
Dr Wiles said it's not believed to be as widely transmitted because there has been fewer secondary cases, however, there's several areas medical professionals are focused.
"There virus has now been sequenced which means that we have the information about it and so that there can be more effort made in identifying people with it. One of the important things is that we also have to wait a little while because one of the ways to find out if people have been affected is to look for antibodies and that takes a few weeks for people's bodies to respond.
"We're always looking for the next pandemic, right, we have to do that, and I think what we're concerned about is there going to be some kind of contagion-style infection where you get something spread through the air, and this is a real case scenario.
"That would be the worst case scenario, that's spread through the air, highly infectious, spreads to lots and lots of people and really deadly, and so that's what people are watching for and we've been lucky it hasn't been one of those so far."