The risk of measles spreading in the community remains “very high”, with the latest outbreak far from over.

Health New Zealand has given an update this afternoon, saying it continues to lead the response with a focus on stamping out cases.

The number of known measles cases nationally remains at 17, of whom 14 are no longer infectious. Sixteen of the cases are still symptomatic.

The 17 known cases have generated 210 exposure events, and 122 of these remain open.

Health New Zealand national director Dr Nick Chamberlain said it was not unexpected to go a few days without new cases.

“It’s actually 42 days after the last case went into isolation or was identified that we can then call the outbreak over.

“We’ve had multiple outbreaks over the last two years. This is by far the worst.”

The risk of the measles outbreak spreading remains “extremely high", Health NZ says. Photo / NZME

Vaccination

Measles is highly infectious and, while vaccination rates are improving, they are not high enough to stop the spread.

Chamberlain said long-term protection depended on lifting immunisation rates.

Since Monday, 8072 MMR doses had been given by Health NZ, he said. Yesterday alone, it administered 2,905 doses.

“To give you an idea just of what protection can be gained from MMR vaccination, someone who’s immune can walk through a ward or room full of people with measles and be effectively bulletproof.

“Whereas someone who isn’t immune has a 90% chance of catching measles even if there’s only one person in the room.”

Health Minister Simeon Brown said contact tracing was being used to help tackle the outbreak. Photo / NZME

Ministry of Health deputy director of public health Dr Harriette Carr said the MMR vaccination was very safe and 99% effective after two doses.

Yesterday, Health Minister Simeon Brown said the health system had enough resources to step up contract tracing efforts if needed.

He made the remarks as he revealed that he had seen modelling showing “there could be a lot more cases than currently we are receiving”.

He said the Government was in the midst of a “stamp it out” approach to the outbreak, using contact tracing.

Labour health spokeswoman Ayesha Verrall said contact tracing was the key to getting on top of the outbreak.

Asked about whether to keep schools open or to close them, she said, “The problem is if actions today that don’t prioritise proper contact tracing lead to a 40 to 50-week outbreak that closes schools around the country – that’s the choice you face during an outbreak.”