The Ministry of Health is warning families thinking of going overseas these school holidays, about how to prevent bringing measles back into the country.

The Ministry is warning people who are going overseas, that the risk of exposure to the disease is higher outside of New Zealand, so vaccinations are a good deterrent.

Spokesperson at the Ministry of Health Caroline McIlray says with school holidays coming up, children and families do go overseas more, which is a risk.

"What we're trying to do is make people more aware is that when you travel overseas, measles is a disease that you can pick up."

It comes after revelations a sixth person in the South Island has contracted the disease.

Health officials are warning people on two Air NZ flights they may have been exposed.
The latest case is a woman in her 20s who travelled while infectious on Air NZ Flight NZ 5642 from Queenstown to Christchurch departing 8.20am on April 7 and Air NZ Flight NZ 5653 from Christchurch to Queenstown departing 3pm on April 9.

Anyone who travelled on either of these flights should check their immunisation status with their GP.

If people who are not immunised become unwell they should phone for advice rather than go to a place where they will infect more people.

During the past week, six cases of measles have now been confirmed in Queenstown, Wanaka, Canterbury and Nelson-Marlborough.

Also as families head off on school holidays, the Ministry of Health is reminding parents to be aware of the risks of measles.

"Measles is a serious and highly infectious disease, and this flurry of new cases shows just how easily it can spread," says Dr Caroline McElnay, Director of Public Health.

For the best protection, people need to have two MMR (measles, mumps, rubella) vaccinations.

The age ranges for those infected in the South Island are 13 months to 46 years old - and infected patients have likely visited supermarkets, restaurants and campgrounds.