The diagnosis rate of a "disease of disadvantage" is steadily on the rise, with indigenous Australians overwhelmingly the most affected.
Rates of acute rheumatic fever and rheumatic heart disease both increased between 2013 and 2017, new data has confirmed.
Children aged between five and 14 were by far the most at-risk.
The fever is a response to an infection of a person's upper respiratory tract, exposing a person to permanent heart damage.
There were 1897 diagnoses of the fever over the five-year period, according to the Australian Institute of Health and Welfare.
Aboriginal and Torres Strait Islander people made up 94 per cent of those cases.
At the end of 2017, there were 4255 Australians living with rheumatic heart disease, with nearly 60 per cent of indigenous people diagnosed aged under 25.
The institute said both diseases were linked to overcrowding, socio-economic deprivation, and low levels of functioning toilets, showers and taps.
Improving access to those basic amenities and improving living conditions would be one of the first preventative measures for the disease, it said in a report released on Friday.
The Northern Territory had the highest diagnosis rates for both diseases in the country.
Only 15 per cent of Aboriginal and Torres Strait Islanders receiving a drug treatment for rheumatic heart disease received 100 per cent of their prescribed doses.
Almost two in five people only received between 50 and 79 per cent of their prescribed doses.
Australian Associated Press