The health agency is warning New Zealanders to make sure they are fully immunised against measles if they plan to travel overseas.

Te Whatu Ora says 15 people travelling to New Zealand two weeks ago had been exposed to a measles case in Australia.

Fourteen were immune and one has been quarantined.

Clinical lead Dr William Rainger says the incident should be taken as a "wake up call".

Measles is highly infectious and cases have been recently reported in Australia, the United Kingdom, the United States and across Asia and the Middle East, says Dr Rainger.

"This is a strong reminder that if people want to avoid the risk of becoming seriously ill while travelling, or while enjoying their overseas holiday, they need to make sure they are fully immunised with two doses of a measles vaccine before they go.

"Being immunised also protects those around you from becoming seriously ill and from spreading the disease to others."

The World Health Organisation has also says there was an "alarming" nearly 45-fold increase in measles cases in Europe last year.

Two doses of the MMR vaccine, which also protects against mumps and rubella, are free for anyone in New Zealand under the age of 18 or anyone eligible for free healthcare.

But for those who can't not remember if they were vaccinated, there's no harm in getting an extra dose, says Dr Rainger.

"Last year, New Zealand had 13 measles cases, many connected to unimmunised people travelling to and from countries where there are cases.

"This is why getting immunised against measles is so important, especially before travelling to and from overseas where measles cases are occurring."

Early symptoms of measles include a fever, a cough, a runny nose or sore and watery eyes.

Dr Rainger says it could take up to 18 days for symptoms to appear.

-RNZ.