New model to predict measles hotspots could prevent outbreaks, study shows

A new method for determining the risk of measles outbreaks could help health officials target catch-up vaccination and education programmes to minimise the harm from preventable disease.

US researchers, led by Johns Hopkins University, used their tool to identify the 25 US counties which have the highest risk of a measles outbreak in 2019 – and say their findings could be applied around the world.

It correctly predicted several of the regions in New York, Washington and Oregon which have seen major outbreaks already this year – some of which have led to public health emergencies being declared.

While vaccination rates are one part of the model, the new findings enhances this picture by including data on international flights and global measles outbreaks, which act as the spark to set off an outbreak.

“There are two critical factors which we know contribute to the risk of measles, one of them is low vaccination rates, the other is international travel,” said Dr Lauren Gardner, one of the authors of the study in the journal Lancet Infectious Disease.

The New York borough of Brooklyn is a perfect example of an at risk borough, because of low vaccination rates among the orthodox Jewish population.

It is also has lots of international visitors, and many of the areas at risk were identified because of their close proximity to an international airport - something which could be used to target disease surveillance schemes.

Using international data on measles outbreaks and travel, the researchers were also able to identify seven countries most likely to transmit measles to the US - namely, India, China, Mexico, Japan, Ukraine, Philippines and Thailand.

While much of the data on measles outbreaks and vaccinations is publicly available, the researchers struck a deal to access flight data from the International Air Travel Association – something other countries could do as well.

“This is definitely a transferable model, it’s very flexible and can be applied to other locations and other diseases as well,” Dr Gardner added, saying that they would like to look at risk across Europe and in Australasia next.

In these countries a rising problem of “vaccine hesitancy” is a factor in measles re-emerging.

This is driven in part by complacency about diseases like measles which, thanks to vaccination, no longer cause deaths, and life-changing injury.

But equally by erroneous fears about the harms of vaccine being stoked by “anti-vaxxers” who have become a global movement thanks to the reach of social media.

This growing trend has a consequences which reach far beyond any one child or person.

“There are people who choose not to be vaccinated, and people whose parents chose for them,” Dr Gardner said.

“But there are also people who don’t have that choice: babies, they can’t be vaccinated until a certain age, and people who can’t for medical reasons – So they’re all exposed.”