A world-first study has reinforced the risk that overcrowded homes and poverty play for children who face rheumatic fever, its lead researcher says.
Otago University public health expert Michael Baker told Breakfast that the science was clear about how governments globally could prevent the serious illness.
Baker said rheumatic fever was a "disease of poverty" that predominantly affected Māori and Pasifika children in New Zealand, alongside Aboriginal children in Australia.
"We know enough to prevent rheumatic fever now. We have to just apply that. The Government, fortunately, is committed to ending child poverty - we know this is not something you can do overnight - this could take decades," he said.
"But we need to be heading in that direction, because children should not be brought up in crowded houses with poor access to healthcare, and they are the factors operating here."
He said the new research had shown strep skin infections played a more significant role in the disease's prevelance than previously known.
"We've always known that it can be caused by a strep sore throat - three weeks later, you get rheumatic fever. But what this research shows is that it can also be caused by skin infection," Baker said.
"And that's really the big breakthrough, because we've been treating strep sore throats for years. But now, we need to actually focus a lot more on strep skin infections, like school sores, particularly in younger children."
He added that there was an unexpected finding in the new research that drew a link between sugary drinks and the illness.
Acute rheumatic fever occurs when the human body's immune system overreacts to bacteria from an inadequately treated strep skin or throat infection - going on to attack its own tissue.
"The reason it's such a concern is that it can progress to cause rheumatic heart disease where your heart valves are damaged. And people can go into heart failure and die in their 20s or 30s, or they need a major heart surgery," he said.
Indigenous and Pacific populations in New Zealand and Australia have some of the highest rates of rheumatic heart disease in the world. In 2015, there were an estimated 233,000 deaths around the world from the disease.
But Baker said research on the illness had stalled after the rates of rheumatic fever fell sharply in wealthy countries.
"Interestingly, because rheumatic fever is not a disease of rich countries now - in general - research has almost stopped on it for the last 50 years," he said.
"When it disappeared from the United States in the 1960s, they said 'problem solved'. And the same for the UK and Europe, they just stopped researching it."
"We found when we looked for the evidence, there's virtually nothing there. And that's why these studies actually are globally important, because no one else is researching this disease in this way."
Baker said the research showed hedging bets on a vaccine wasn't enough.
"It may take many years to get an effective vaccine, [and in the meantime] we need to really work on improving housing conditions for children - and also specifically treating skin infections better. That'd be the two big messages," he said.
The world-leading research has been published online and can be found through the University of Otago's website.