Two people, including a baby, had measles symptoms so severe they were admitted to hospital at the weekend, health authorities say.
The new cases bring the number of confirmed measles cases connected to a hip-hop event in December to 16 - one in Auckland, two in Wellington, and 13 in the Taupo-Turangi area.
In Taupo-Turangi, a 15-month-old baby was admitted to hospital on Friday, but has since been discharged, and an adult was also admitted and is still undergoing care.
Medical officer of health Phil Shoemack said both were admitted because of the severity of their symptoms.
''They were both sufficiently unwell that the best place for them was hospital,'' he said.
Dr Shoemack said they are still confident the outbreak has been somewhat contained, as all of those who were unwell had either been at the World Supremacy Battlegrounds event in Sydney or were in direct contact with someone who was.
''It's not a community outbreak in that regard,'' he said.
About one in 1000 people who get measles in New Zealand die and, as with any outbreak, there is a risk of complications.
Anyone born before 1969 is considered likely to be immune to the infectious disease, as are those who have had the MMR - measles, mumps and rubella - vaccine, introduced in 1990.
Those vaccinated in the 1970s and '80s may be at risk, as there is uncertainty over the effectiveness of the shots they received, depending on the age at which they received them and the way the vaccine was stored.
Anyone found to have been in contact with an infected person, or who is unsure of their vaccination status, is given a blood test to check for antibodies.
Anyone found not to have immunity is asked to stay in isolation for 10 days to see whether symptoms develop.
Anyone who thinks they have measles symptoms - such as a fever, sore and watery 'pink' eyes, and small white spots inside the cheeks of the mouth - should call their GP or Healthline on 0800 611 116.