More than 150 people have been hospitalised in Auckland this year, so far, after contracting measles.
The Auckland Regional Public Health Service said that as of 12pm today, a total of 369 confirmed cases of the highly contagious and infectious disease had been recorded in Auckland this year.
Yesterday, the total number of cases in the region stood at 356.
Of those, 156 people had been hospitalised; resulting in a 43.8 per cent of cases ending up at an emergency department.
The Counties Manukau District Health Board recorded 216 people had been hospitalised. The Auckland DHB said they had seen 47 cases, while the Waitematā DHB had had 93 cases.
"Someone is regarded as hospitalised in our data if they spend more than three hours in the emergency department being assessed or having tests - regardless of whether they are formally admitted,'' an ARPHS spokeswoman said.
Public Health Medicine Specialist, Dr Maria Poynter, said of the cases that have been confirmed, many of them were children or young people.
A total of 40 youngsters at 24 early childcare centres had contracted the disease, she said.
Another 55 students in 34 schools around the region had come down with it and five teachers had been confirmed with measles.
"The two age groups most affected in this outbreak are children under 5 years old - which made up 39 per cent - and young people aged 15 to 29 years old - which made up 35 per cent of cases.
Those most affected were from the Pacific Island community and within that community, the majority of the cases were Samoan and Tongan. A total of 46 per cent of measles cases identified as being of Pasifika descent.
Māori made up 25 per cent of confirmed cases.
"Schools require students and staff who have suspected measles to seek medical attention and stay at home unless they are cleared of having the illness,'' Poynter said.
"They have to stay away from school while they are infectious.''
Poynter said the case numbers did not reflect the disruption schools and early childhood education centres faced when a pupil or student had symptoms or was confirmed to have measles.
"A school requires all students and staff members exposed in the same class, team or school group as the individual with measles to stay in quarantine for one to two weeks if they are not vaccinated or immune.
"They may be developing measles without knowing it and may be able to infect others at school.''
She said it was sometimes difficult for older school teachers or students born overseas to find immunisation records and so they still needed to be quarantined because immunity was not known.
In daycare centres, some children - particularly those under 12 months of age - could not be vaccinated for various reasons and so were asked to stay home because they are not immune. That was the same case for teachers.
"Measles cases in early childhood centres are of particular concern because babies can get very ill from measles and many have been hospitalised. Measles can cause complications for non-immune pregnant staff and mothers as well.
She stressed the importance of getting immunised against the disease; with the measles, mumps and rubella (MMR) vaccination - which is free for people aged 50 - protecting 95 per cent of people from the disease.
"Measles can make you miserable and we have seen a high rate of hospitalisation in this outbreak. The vast majority of people would not have had to stay in isolation or quarantine if they had had even one MMR vaccination."
Once a person contracts measles, it can be 10 to 14 days before they begin seeing symptoms; which include high fever, a runny nose, sore red eye and later, a rash that starts from the face and neck and spreads to other parts of the body.
• If you are concerned about measles call Healthline on 0800 611 116 or call your GP. Please do not just turn up to your GP, after hours or emergency department as you could potentially infect others.