A health expert says it was only a matter of time when measles cases appeared in Waikato.
Three cases have been confirmed in the region, as the Auckland outbreak hits 731 confirmed infections.
Waikato DHB Medical Officer of Health Richard Hoskins says the risk of further cases is high.
"With the number of cases in south Auckland and that being almost part of the Waikato, it was inevitable - as long as the cases were high in south Auckland - that we would get some."
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The Auckland Regional Public Health Service on Thursday recorded another 31 cases, almost all of them in the Counties Manukau DHB region, which borders Waikato to the south. It's the biggest outbreak in New Zealand this century, and mirrors an increase in cases worldwide.
"We do see misinformation as an increasing threat," the World Health Organization's immunisation director Kate O'Brien said on Thursday.
"We are calling on social media providers, communities, leaders, people who speak out, to be sure you are communicating accurate, valid, scientifically credible information."
Dr Hoskins says a large number of young people here in New Zealand are not immunised.
"Maybe 15 to 20 percent based on the scientific information we've got. Those people are very hard to reach, and even if you do reach them, very hard to motivate to go for a preventative health initiative."
There have also been confirmed cases in Taranaki and Queenstown.
Dr Hoskins wants more funding put into making immunisation more accessible.
"At the same time I'm aware there's huge other competition for Government resources. As of yet, that need hasn't been a high-enough priority."
The Ministry of Health has issued advice for people travelling to Auckland to "make sure you're vaccinated against measles at least two weeks before you go".
"There is also a risk that people travelling from Auckland to other centres may spread measles. If you're feeling sick, you should reconsider travel arrangements, stay away from work, school and public places, to help prevent putting other people at risk."
Measles has officially been eradicated from New Zealand, with all new outbreaks originating from overseas.