Rheumatic heart disease could be spread between Indigenous children by throat bacteria, Australian researchers have found.

RHD is a chronic and severe disease which is mostly found in low-and middle-income countries but is widespread in remote Indigenous communities in Australia.

The disease is caused by repeated infections of the highly contagious Strep A bacteria which can lead to irreversible heart damage requiring surgery to replace or repair damaged heart valves.

In an effort to gain more understanding of the spread of the disease, researchers from the Doherty Institute in Melbourne analysed hundreds of strep A bacterial samples collected from remote communities almost 20 years ago.

Lead research scientist Professor Steven Tong says genome sequencing revealed the strep A bacteria found in the throats of people with no symptoms was the same as that found in people with skin infections and symptomatic disease.

Professor Tong said the discovery could help to inform vaccine development and prevention.

“There’s no licenced strep A vaccine yet, but there are some which are coming down the pipeline and so it’s going to be really important for studies that look at the impact of these vaccines that they consider throat carriage as well – this kind of hidden reservoir.”

Between 2015 and 2019 there were 1,325 RHD diagnoses among Indigenous Australians – with more than half those detected in people aged under 25. The disease killed about 400 people over the same time period.