An Auckland mother has hit out at health officials after an 11-day delay in being notified her baby boy might have been exposed to the measles virus in a hospital waiting room.

The woman - a trained nurse who did not want to be named - took her 5-month-old son to the Emergency Department at Waitākere Hospital on May 13 after a head injury.

He was later transferred for treatment at Starship Children's Hospital.

On Friday, 11 days after the family were at Waitākere Hospital, the boy's mother received a text message from the Auckland Regional Public Health Service, notifying her of the possible exposure.

Advertisement

The text message provided a link to information which would help her clarify whether or not she and her son needed to go into quarantine.

"We should have been informed four days ago, when he should have been incubated and in quarantine - just in case he's at risk," the woman told the Herald on Sunday.

"My son might not show symptoms for another four or five days, but he's still potentially contagious if he was to have contracted measles."

While the mother is worried the delayed notification might have put her son, and others, at risk, the Auckland Regional Public Health Service has defended the notification period.

The text message the Auckland woman received from Auckland Public Health. Image / Supplied
The text message the Auckland woman received from Auckland Public Health. Image / Supplied

Medical officer of health Dr William Rainger said when an adult or child was exposed to measles in a hospital waiting room, the hospital would provide a list of people present at the same time as the case - and for two hours afterwards.

"This takes time to compile, as does identifying adults and children in the waiting room who may be at risk."

Rainger said the service had contacted more than 3200 people since February to tell them they had been exposed to measles and to check they were immune.

"We ask anyone not immune to go into quarantine," she said.

Rainger said ARPHS hadn't received a complaint from any contact of a measles case, but would investigate if it did.

The mother was concerned she and her son could have spread the virus to others - if they had in fact contracted it.

"You're meant to be in quarantine for about seven days," she said.

The woman said neither she nor her son had so far shown any symptoms to indicate they had contracted the virus.

Symptoms can include fever, cough, conjunctivitis and a rash.

She believed the initial carrier that they were exposed to had not been immunised and hit out at parents who didn't get their children vaccinated.

"We have vaccines that have absolutely eradicated things like polio and smallpox. There is no cause, even after massive, massive, extensive research, to say that [immunisations] have any link to autism."

Auckland and the Bay of Plenty have been particularly affected in the measles outbreak in New Zealand. The outbreak in Canterbury has been declared officially over.

As at Friday afternoon, there had been 69 confirmed cases of measles in Auckland this year.

Another 23 cases of measles had been confirmed in the Bay of Plenty since April 1 - of which 8 have been admitted to hospital.

The Ministry of Health recently highlighted that since 2012, all outbreaks of measles in New Zealand were started by travellers bringing the disease from overseas. There are currently significant measles outbreaks in many countries.

Information on the Ministry of Health website describes measles as a "serious and highly contagious" illness that can affect adults as well as children.

Measles patients are infectious five days before and until five days after the rash appears.

Almost everyone over the age of 50 would have had measles as a child and was therefore immune, the Ministry said. Ninety per cent of people in their 30s and 40s are immune, while teenagers and young adults are least likely to have been immunised as young children.

Anyone given one dose of the MMR vaccine has a 95 per cent chance of being immune to the virus, while two doses (given at least four weeks apart, and the first dose given after age 12 months) increases chance of immunity to 99 per cent.