Contact tracers are scrambling to keep up now the country has at least 11 confirmed cases in five different regions.
Of these cases, one is linked to overseas travel, and the remaining 10 were locally acquired.
Of particular concern in recent days is the fact three of the cases were confirmed at two Wellington secondary schools.
The last measles epidemic here was in 2019 when 775 cases required hospital treatment. That was more than a third of the more than 2200 cases which were spread over 17 district health board areas, including Southern.
Two unborn babies died, and when the strain spread to Samoa, there were 83 deaths.
That tragedy should have been a wake-up call.
This highly contagious disease can kill and must be taken seriously.
Before the introduction of the measles vaccine in 1963, major epidemics occurred around the world every few years, causing an estimated 2.6 million deaths a year.
In a 1991 New Zealand epidemic, seven people died.
In pre-vaccination times, there were some years where there were large numbers of deaths in this country, with the worst last century being 375 deaths of children and adults in 1938.
Although we have known for years our vaccination rates were too low to offer herd immunity, and that the coverage among Māori and Pasifika families was lower than for other groups, moves to address this have been piecemeal.
This was highlighted by the World Health Organisation warning, which said in a review last year New Zealand was at risk of another large measles outbreak if it did not urgently close "alarming" gaps in immunisation, particularly for Māori and Pasifika.
In 2020, the then Labour-led government announced a catch-up campaign for measles, mumps and rubella (MMR) vaccinations.
When it dribbled to a halt in June 2022 as district health boards were disestablished, it had cost $32 million, almost 24,000 people had been vaccinated, and about $8 million worth of vaccines had expired.
That campaign was affected by resources being diverted to the Covid-19 pandemic and likely by some vaccine hesitancy.
Another issue was the difficulty in working out how many people needed to be vaccinated because before 2005 there was no central vaccination register.
However, since the failure of that campaign, it is hard to see any cohesive effort to cover this cohort of young people who might lack protection.
The current government has made much of the progress it is making on immunising infants, but it is not universal and rates are still too low.
Northland, one of the areas where some of the recent cases occurred, has the poorest coverage. Its most recently reported figures were heading the wrong way.
It was good to hear Health Minister Simeon Brown say this week a National Measles Immunisation Week is being planned where all immunisation providers across the country will focus on MMR vaccinations.
The vaccine is free for everyone, including tourists.
People born or living in New Zealand before 1969, before the vaccine was introduced, are considered immune because of their childhood exposure to the illness.
Whether the immunisation week initiative will be enough to stop an epidemic now remains to be seen.
There is a long way to go to get from the current about 80% immunity rate to the 95% coverage considered to provide herd immunity.
New Zealand is not alone in facing rising measles cases. Measles outbreaks are occurring in every region of the world and including countries such as Canada and the United States.
It is easy for unvaccinated international travellers to pick up the illness abroad and then spread it among poorly protected populations after returning home.
Now, if we want to avoid deaths and the misery of large numbers of serious cases which could overwhelm our stretched hospitals, we must act on the public health advice about vaccinations urgently.
