It is not clear whether the four young people struck by measles in recent weeks were immunised, public health authorities say.
This comes as one person remains in Tauranga Hospital following an announcement on Tuesday that there were four cases of measles in the last three weeks, all with connections to the Mount Maunganui area.
The other three people had already recovered when Tuesday's announcement was made.
Toi Te Ora Medical Officer of Health Dr Jim Miller said no further cases have been reported since and it was not possible to provide more specific information on the infected people's whereabouts.
"All of the recent cases have been in young adults who were staying in the Mount Maunganui area and would have visited many locations over the past few weeks," he said.
He had previously said it was unclear whether the Mount Maunganui cases had any connection with the Christchurch or Auckland outbreak.
Miller said everyone needed to be vigilant and ensure they were up to date with their immunisations, especially the MMR (measles, mumps and rubella) vaccine.
The Bay of Plenty Times asked why the cases were not made public earlier.
Miller said he was informed of a suspected case on April 4 and this was confirmed by laboratory testing late the following day.
Investigation and contact tracing then took place during the weekend and healthcare professionals were alerted to the confirmed case on Monday, with a media statement issued that afternoon, he said.
Miller said more suspected cases were identified during the investigations into the notified case.
If someone suspected a case of measles, Miller urged them to call their GP ahead of making an appointment to avoid potentially spreading the disease in the doctor's waiting room.
As of last week, 67 people were confirmed to have measles in New Zealand this year, including 39 in Canterbury and 12 in Auckland.
About measles
• Measles is a highly infectious viral illness and is spread from person-to-person through the air by breathing, sneezing or coughing. Just being in the same room as someone with measles can lead to infection if you are not immune.
• Measles can be serious with around one in 10 people who get measles needing to be hospitalised.
• Early symptoms include a fever, runny nose, sore red eyes and cough.
• After three to five days a red, blotchy rash appears on the face and head and then spreads down the body.
• Anyone who thought they had measles should stay home and call their doctor or Healthline to arrange an assessment, to avoid putting anyone else at risk.
• Anyone who thinks they have been exposed to measles or is exhibiting symptoms, should not go to the ED or after hours clinic or general practitioner. Instead, call your GP any time, 24/7 for free health advice.
• For more information or advice on measles, please call Healthline on 0800 611 116 or see the Ministry of Health's measles page.