Why is it important?:Acute rheumatic fever (ARF) is a disease caused by an auto-immune reaction to a bacterial infection with Group A streptococcus. ARF is a short illness, but can result in permanent damage to the heart—rheumatic heart disease (RHD). A person who has had ARF once is susceptible to repeated episodes, which can increase the risk of RHD. Following an initial diagnosis of RHD, patients require long-term treatment, including long-term antibiotic treatment to avoid infections that may damage the heart (Steer & Carapetis 2009).
ARF and RHD are associated with environmental factors such as poverty and poor living conditions. The incidence of ARF and the prevalence of RHD among Aboriginal and Torres Strait Islander peoples living in some remote areas have been reported as among the highest in the world (AIHW 2004b).
ARF and RHD are now rare in populations with good living conditions and easy access to quality medical care (Parnaby & Carapetis 2010). Aboriginal and Torres Strait Islander peoples will remain at risk of ARF/RHD while socioeconomic disadvantage and barriers to accessing health care persist.
Data on ARF and RHD are currently only available for the Northern Territory (from the Northern Territory Rheumatic Heart Disease Program) and a study conducted in North Queensland.
Findings:In the period 2006–09, there were 216 new or recurrent cases (prevalence) of ARF in the Northern Territory. The majority (99%) were for Aboriginal and Torres Strait Islander peoples. ARF is largely restricted to older children and young adults: 62% of cases occurred in children aged 5–14 years, with a further 21% in the 15–24 years age group. Females comprised 61% of all cases of ARF in 2006–09 (130 females, 83 males).
Incidence (new reported cases) of ARF in the Northern Territory rose from the mid 1990s to the early 2000s. Between 2006 and 2009 no significant differences were detected. Between 1995–97 and 2004–06, ARF incidence rates have been higher in Central Australia compared with the Top End of the Northern Territory. However, in the latest period, rates were similar in the two regions.
Outside the Northern Territory, a study of ARF incidence in north Queensland over the period 2004–09 showed an increase in notifications but fewer recurrences, suggesting enhanced awareness of the disease (Hanna & Clark 2010).
In December 2009, there were 1,479 people recorded as having RHD in the Northern Territory. Of these 1,374 (93%) were Indigenous Australians. The prevalence of RHD in Indigenous people was higher in the Top End compared with Central Australia (28 versus 18 per 1,000 persons). Females comprised 65% of Indigenous Australians in the NT with RHD. After adjusting for the age differences, the prevalence of RHD was 29 times as high in the Aboriginal and Torres Strait Islander peoples than in other residents of the Top End of the Northern Territory, and 18 times as high in Central Australia.
A recent study of patients with RHD living in five communities around Katherine in the Northern Territory found that around two-thirds of patients were receiving ongoing secondary preventive treatment in accordance with guidelines: 56% of patients received prophylactic penicillin injections; 63% received echocardiograms and 59% had a specialist review (Stewart et al. 2007).
Implications:The Northern Territory is the only jurisdiction in which there is time-trend information for ARF. The incidence of ARF among Indigenous Australians is apparently lower in north Queensland than in the Northern Territory, but is still far higher than for other Australians. Since there are no trend data on ARF or RHD in Queensland, it is unknown whether rates have been lower there for many years or whether progress has been made in recent years.
Interventions that focus on improving housing, socio-economic circumstances and health care will be important for preventing and managing these conditions.
Improved access to appropriate treatment for pharyngitis/tonsillitis is likely to reduce the rate of ARF. Although the role of Group A Streptococcal Bacterium (GAS) skin infection in precipitating ARF is contentious, it appears likely this plays a role in the spread of ARF in Australia. Interventions to reduce GAS skin infection through community-based skin health programs may be effective.
There is considerable scope for the secondary prevention of ARF/RHD through the implementation of disease register and control programs, education of patients and their families, treatment with penicillin prophylaxis, and regular clinical review and access to specialists and hospital care. There is evidence that current practice could be improved (Stewart et al. 2007).
In the Northern Territory, RHD registers are a central element of secondary disease prevention programs to prevent recurrence of ARF and reduce the occurrence or severity of RHD. Work is underway to extend this approach to other jurisdictions. Under the Rheumatic Fever Strategy, register and control programs are being established in Queensland and Western Australia. A National Coordination Unit, RHDAustralia, has been established at the Menzies School of Health Research. The unit is developing culturally appropriate education and training materials and establishing a national data collection system. RHD registers are primarily intended to improve secondary prophylaxis by allowing health professionals to follow-up with patients who have not returned for their monthly treatment. Control programs improve case-detection, and are the most effective way of improving compliance to treatment regimes and supporting clinical follow-up of people with RHD.
Figure 17 – Acute Rheumatic Fever incidence, NT Indigenous Australians by time period, Top End of Northern Territory and Central Australia, 2006–2009
Source: AIHW analysis of Top End and Central Australian Rheumatic Heart Disease Registers
Text description of figure 17 (TXT 1KB)
Table 12 –Rheumatic Heart Disease prevalence (31 December 2009) by age groups for Aboriginal and Torres Strait Islander people in the Northern Territory
RHD prevalence - 31 December 2008
* Represents results with statistically significant differences in the Indigenous/ Non-Indigenous comparisons at the p<.05 level.
Source: AIHW analysis of Northern Territory Rheumatic Heart Disease Program