A 10th case of measles has shown up in Northland with six other suspected cases being investigated but not yet confirmed.
The 10th person is a relative of a previously confirmed case and has been in isolation at home.
Three of the earlier Northland cases were linked to outbreaks overseas or elsewhere in New Zealand, and the seven further confirmed cases are all related to one of those initial three cases.
Northland District Health Board is asking parents to ensure their children are vaccinated before the school holidays arrive - a time when families travel, have visitors or attend more public places.
Public Health Nurses are offering the MMR (measles, mumps and rubella) vaccination to children and staff at the schools they are currently visiting with the Boostrix immunisation (diphtheria, tetanus and whooping cough). Parents are being given a consent form to return to school.
''We know that the MMR coverage of our 11-12-year-olds is around 75 per cent, and testing for measles immunity suggests that one in five people in Northland aged 13 and 29 are not immune to measles,'' Medical Officer of Health Dr Catherine Jackson said.
Almost everyone aged 50 or older had measles as a child and is therefore naturally immune. Teenagers and young adults are least likely to have been immunised as young children.
''With school holidays coming up it would be a good idea for parents to make an appointment with their general practice for their teenage children to be vaccinated,'' Jackson said.
''I can't emphasise enough the importance of everyone getting their immunisations up to date given the recent cases of measles in our community. Now is the time to act.''
The NDHB would not give the age group of the latest person with measles.
People aged 15-months to 50-years who have not previously been vaccinated against measles can have a free vaccination at their general practice. Anyone not sure of their or their children's vaccination history can check in their Well Child/Tamariki Ora (or Plunket) book or ask their general practice.
Measles symptoms start with a fever and cough and runny nose and sore red eyes, with a rash appearing on the face after three or four days then spreading to the body.