The number of people infected with the measles in Waikato is continuing to climb.
Waikato District Health Board says it is dealing with 15 confirmed cases, up from 13 two days ago, with another 12 under investigation.
Medical officer of health Richard Wall said four of the confirmed cases had not come from any of the earlier detected cases, showing the disease had now spread wider in the community.
He said another person had also used public transport in Hamilton while infected.
The rise was a timely reminder for people to look out for symptoms and to check whether they and their children were vaccinated, Mr Wall said.