What is acute rheumatic fever?

Acute rheumatic fever (ARF) refers to an autoimmune response to infection of the throat and possibly of the skin by group A streptococcus (Strep A) bacteria (McDonald et al. 2004). Not all people who have a streptococcal infection develop ARF but, in those affected, it usually develops within 2–3 weeks of the infection (Webb 2015).

ARF can affect the heart, joints, brain and subcutaneous tissues (innermost layer of skin) and can be extremely painful (Parnaby & Carapetis 2010). While there is no lasting damage caused to the brain, joints and skin, ARF can cause lasting damage to the heart. There is no single diagnostic test for ARF. Australian guidelines recommend hospitalisation so all necessary investigations are undertaken and to rule out other diagnoses.

The risk of ARF recurrence is relatively high after an initial ARF episode and repeated episodes increase the likelihood of long-term heart valve damage, known as ‘rheumatic heart disease’ (Carapetis et al. 2016). As each episode of ARF can worsen the damage to the heart, the priority in disease management is to prevent ARF recurrences using long-acting penicillin treatment, which is known as secondary prophylaxis.

Refer to Acute rheumatic fever for more information.

What is rheumatic heart disease?

Rheumatic heart disease (RHD) is most commonly caused by damage to heart valves as a result of ARF. An affected heart valve can become scarred and/or stiff, obstructing blood flow (stenosis), or it can fail to close properly, causing blood to flow backwards in the heart instead of forward around the body (regurgitation). The mitral and aortic valves are most frequently affected. Regurgitation due to damage to the mitral valve is the most common feature of RHD.

Figure 1: Diagram of the heart, emphasising the heart valves.

Diagram of a heart showing the pulmonary valve, aortic valve, tricuspid valve and mitral valve.

Symptoms of RHD include fatigue, chest pain, swelling of legs and face, and shortness of breath. Diagnosis can be difficult as symptoms are shared with other cardiac diseases.

The type of valve affected and severity of damage, along with a history of ARF, are important clinical indicators for RHD diagnosis. Many patients can remain asymptomatic despite having moderate or severe RHD. If left untreated, RHD can cause arrhythmias (heart beats too fast, too slow, or irregularly), stroke, endocarditis (infection of the inner lining of the heart or its valves), complications of pregnancy, and may be fatal.

Management of RHD includes treating symptoms and preventing worsening of disease, which requires regular echocardiography (echo) to identify and monitor which valves are damaged and how badly. Management of an RHD diagnosis is complex and involves coordination of multiple services such as primary health care, secondary prophylaxis with penicillin, monitoring of heart medications such as anticoagulation therapy, oral healthcare services, obstetrical and gynaecological services, echo, specialist medical care, and other cardiothoracic and interventional cardiology services (RHD Australia 2012).

Refer to Rheumatic heart disease for more information.

ARF and RHD are preventable diseases

ARF and RHD are both preventable diseases. They are common in low- and middle-income countries, and in socioeconomically disadvantaged populations in high-income countries (Wyber 2015; Webb 2015). ARF and RHD are linked with household crowding, socioeconomic deprivation, and low levels of functioning ‘health hardware’ (for example toilets, showers, taps, etc.) and lack of access to health care services (Webb 2015; Sims et al. 2016). Improved living conditions and access to functional health hardware can reduce high rates of Strep A infections and progression to ARF (Katzenellenbogen et al. 2017). Prevention measures that improve living conditions, environmental health and address other determinants of ARF are known as primordial prevention measures.

After a Strep A infection, progression to ARF is preventable through early treatment. This is called primary prevention of ARF and relies on correct diagnosis and treatment of skin and throat infections with antibiotics as soon as possible after onset of symptoms.  Timeliness of diagnosis and subsequent treatment can be negatively affected by health service access issues and delayed presentation to health services. The effectiveness of primary prevention is also compromised when the prescribed treatment does not comply with clinical guidelines (RHD Australia 2012).

Secondary prevention of the progression from ARF to RHD relies on correct diagnosis of ARF, to enable commencement of regular antibiotic preventive medication. Correct diagnosis is challenging as there is no specific single laboratory test for ARF, and it can be misdiagnosed. Diagnosis is based on clinical criteria outlined in the Australian modification of the Jones criteria, which take into account Australia’s high-risk groups (Technical information Table 4, and RHD Australia 2020 Chapter 6).

For people with suspected or clinically confirmed ARF episodes, benzylbenzathine penicillin G (BPG) is recommended in order to prevent further Strep A infections and thereby reduce the risk of developing recurrent ARF. BPG prophylaxis is clinically effective and cost-effective for RHD control at both individual and community levels (Webb 2015; Wyber & Carapetis 2015; RHD Australia 2012).

Preventing ARF and RHD

As the development and progression of ARF and RHD are affected by multiple factors in different stages, interventions at several points are required for effective prevention (Figure 2). These include:

  • Primordial prevention: Improving access to functional health hardware and improved living conditions such as reducing crowding in households, reducing high rates of Group A streptococcal infection.
  • Primary prevention: Preventing progression to ARF through correct diagnosis and early treatment of Group A streptococcal infections.
  • Secondary prevention: Regular antibiotic preventive medication to prevent recurrences of ARF, progression of ARF to RHD.
  • Tertiary prevention: Heart failure medication, heart surgery, and anticoagulation.

The RHD Endgame Strategy describes an ‘indicative bundle’ of strategies that show the greatest promise in preventing new cases of RHD over the next decade. These strategies include reducing household crowding, improving hygiene infrastructure, strengthening primary healthcare, and enhancing the delivery of secondary prophylaxis. Modelling estimates that 69% of ARF and 71% of RHD cases would be reduced, and 471 deaths would be prevented if these strategies are implemented together. It would also save $188.2 million on ARF and RHD related healthcare expenditure (Wyber R et al. 2020).

Figure 2: Stages of ARF and RHD prevention

Chart: AIHW.