The rise of anti-vaccine messages on social media is a driver for the global increase in measle cases, a health expert says.
The number of cases world wide has increased by 300 per cent in the first three months of this year compared to 2018.
Facebook has been facing challenges combating widespread misinformation about measle vaccines from anti-vaxx groups on its site, breeding false information about the danger of vaccines and reasons why people shouldn't get vaccinated.
Doctor Helen Petousis-Harris told TVNZ1's Breakfast the spread of this misinformation "is scaring people" and is a driver for the rise of measle cases globally, but there are other contributing factors.
"In some countries you’ve got huge access barriers to getting the vaccine."
In Madagascar, 1,200 people have died with cases soaring well beyond 115,000. Parents in Madagascar want to protect their children but many are desperately poor and lack resources.
"They're getting the vaccine but they're not getting enough. So they've had a lot of diseases, they've become naturally immune, the disease has settled down and a lot of susceptible people have now built up in those communities. Bring the disease in and away it goes," Dr Petousis-Harris says.
"In other places around the world we've had a decline in vaccination due to hesitancy," she says, partly due to the anti-vaccine messages.
Dr Petousis-Harris says some people are also not taking quarantines seriously enough, which contributes to a spread in cases.
New York is currently experiencing a measles outbreak and children susceptible to it were not allowed to go to school or allowed in public places, but many parents disagreed and ignored the quarantine.
"When you have outbreaks like this you need to keep the people who are susceptible, all the unvaccinated kids, away from school. People refuse to do that so children who are susceptible are still going to school and parents were ignoring the quarantine," Dr Petrousis-Harris says.
"Punishment is a very harsh thing but I think the situation left the public health officials with no where else to go to try and control this because ultimately this could lead to more deaths.”
This year a total of 78 measle cases have been confirmed in New Zealand.