The measles virus. Photo: Supplied/ US CDC
For a disease that's so contagious, measles is remarkably good at staying below the radar - usually until many people have already been exposed and unwittingly passed it on themselves.
Manawatu District Council's incoming mayor Michael Ford said the news that students from up to four Feilding schools may have been exposed to measles on their bus was causing anxiety for locals.
"It's a serious and highly contagious illness and we're just hoping it doesn't spread too far."
According to Health NZ, anyone who travelled on the ZigZag Road Bus on Monday 18 October from Colyton School to Feilding Intermediate, Manchester Street and Feilding High School - or did the reverse trip that afternoon - may have been exposed to measles.
Families were being told told to call Healthline and stay home.
Ford said Feilding Healthcare and pharmacies were offering catch-up vaccinations - and there's a bit of catching up to do, with just 69 percent of the district's two-year-olds fully-vaccinated.
"That's disappointing and I guess we use an opportunity like this to remind everyone how effective vaccinations are. We just want to keep everyone safe."
Nationwide, only about 80 percent of New Zealanders have immunity against measles - much lower than the 95 percent needed to prevent a widespread outbreak.
Māori children have the lowest protection with only 68.4 percent of two-year-olds vaccinated at the end of June, compared with 82 percent nationally.
General Practice New Zealand chair Bryan Betty, a Porirua GP, said unfortunately it was very young babies who were most at risk of severe complications.
"We can't vaccinate our young children until they are 12 months so less than 12 months are really, really at risk from measles."
Following the 2019 measles epidemic, the age for the first dose of the vaccination was brought forward to 12 months, with the second at 15 months.
Infectious disease expert Dr Chris Puli'uvea - an immunology lecturer at AUT - said measles was particularly virulent because it was able to infect specialised immune cells that fought infection.
"It sort of behaves like a Trojan horse because it enters these immune cells, which travel to other parts of the body."
Measles suppresses the immune system, which leads to secondary infections and complications in about a third of cases.
These can leave babies deaf, blind, brain-damaged or even dead.
It was extremely easily spread by coughing, sneezing or even talking, he said.
"It can infect between 15 and 18 other people so it's far more contagious than Covid or the flu, and it also can hang around for up to two hours in the air, in little droplets."
The measles, mumps and rubella vaccination is free for anyone under 18 and for those over 18 who are entitled to funded healthcare.
For a full list of locations of interest, please check the Health NZ website.
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