Acute Rheumatic Fever and Rheumatic Heart Disease: Incidence and Progression in the Northern Territory of Australia 1997-2010
Background—Although Acute Rheumatic Fever (ARF) and its sequel Rheumatic Heart Disease (RHD) continue to cause a large burden of morbidity and mortality in disadvantaged populations, most studies investigating the effectiveness of control programs date from the 1950s. A control program, including a disease register, in the Northern Territory (NT) of Australia where the Indigenous population has high rates of ARF and RHD, allowed us to examine current disease incidence and progression.
Methods and Results—ARF and RHD incidence rates, ARF recurrence rates, progression rates from ARF to RHD to heart failure, and RHD survival and mortality rates were calculated for NT residents from 1997 to 2010. For Indigenous people, ARF incidence was highest in the 5-14 year age-group (males 162, females 228 per 100,000). There was little evidence that the incidence of ARF or RHD had declined. The ARF recurrence rate declined by 9% per year. After a first ARF diagnosis, 61% developed RHD within ten years. After RHD diagnosis, 27% developed heart failure within five years. For Indigenous RHD patients the relative survival rate was 88.4% ten years after diagnosis and the standardized mortality ratio was 1.56 (95% CI 1.23-1.96).
Conclusions—For Indigenous Australians in the NT, ARF and RHD incidence and associated mortality remain very high. The reduction in ARF recurrence indicates that the RHD control program has improved secondary prophylaxis; a decline in RHD incidence is expected to follow.
- Received January 25, 2013.
- Revision received May 31, 2013.
- Accepted June 10, 2013.