- Rheumatic heart disease is caused by repeated episodes of acute rheumatic fever, an abnormal immune response to streptococcal throat infection, that progressively damages the heart valves.
- The causative organism is Group A Streptococcus, the same bacteria responsible for strep throat. In high-income countries, prompt antibiotic treatment prevents the inflammatory cascade. In low-resource settings, untreated infections lead to rheumatic fever and lasting valve damage.
- The mitral valve is most commonly affected, producing stenosis or regurgitation that worsens with each recurrent episode of rheumatic fever. The aortic valve is the second most frequently involved.
- Rheumatic heart disease remains the leading cause of acquired cardiovascular disease in children and young adults worldwide, predominantly affecting people in low and middle-income countries, including our nearest neighbour, Timor-Leste.
- Prevention is straightforward and inexpensive, prompt antibiotic treatment of streptococcal throat infection and long-term penicillin prophylaxis for those who have had rheumatic fever. The tragedy is one of access, not of medical complexity.
In Australian cardiology practice, rheumatic heart disease is a condition most cardiologists encounter rarely, a case here, a patient referred from overseas there. For many of my colleagues it exists mainly in textbooks, as a historical curiosity from an era before widespread antibiotic use.
But spend a week in the cardiac clinic at Hospital Nacional Guido Valadares in Dili, Timor-Leste, as I have, and the picture changes completely. You see young people in their twenties and thirties with severely damaged mitral valves. Children with significant valve disease. Patients who have never had access to the antibiotics that would have prevented everything they are now facing.
Rheumatic heart disease has not gone away. It has simply moved to places where we are less likely to see it, and where the people affected have less power to demand the attention their condition deserves. It remains the leading cause of acquired cardiovascular disease in children and young adults worldwide, affecting an estimated 40 million people and killing hundreds of thousands every year.
This article is about raising awareness of a condition that is preventable, treatable, and profoundly under-prioritised, and about the work being done to change that.
Heart Matters, Supporting the Timor-Leste Hearts Fund
The Timor-Leste Hearts Fund is Australia’s only medical NGO dedicated to life-saving heart surgery and heart health education for young people in Timor-Leste. Prof. Peter Barlis serves on the board and has worked on the ground in Dili supporting the Fund’s cardiac screening and skills training programs. Every donation makes a direct difference to a young person’s life.
The Causative Organism, Group A Streptococcus
A familiar bacteria with an unfamiliar consequence
Group A Streptococcus, Streptococcus pyogenes, is the bacteria responsible for strep throat. In Australia and other high-income countries, it is a common childhood infection that is diagnosed with a throat swab and treated with a course of antibiotics. Most children recover completely within days and never think about it again.
In settings where access to diagnosis and antibiotics is limited, or where poverty, overcrowding, and inadequate housing amplify the transmission and recurrence of streptococcal infections, the story is very different. When strep throat goes untreated or undertreated, some individuals mount an abnormal immune response. The immune system, primed to attack the streptococcal proteins, begins to cross-react with the body’s own tissues, including the heart. This is acute rheumatic fever.
Why the immune system attacks the heart
The mechanism of cardiac damage in rheumatic fever is molecular mimicry, proteins on the surface of Group A Streptococcus are structurally similar to proteins found in the human heart, particularly in the valve tissue. The immune system, mounting a response to the infection, cannot reliably distinguish between the bacterial proteins and the cardiac proteins. The resulting inflammatory attack damages the endocardium, the inner lining of the heart, and in particular the heart valves.
This is not a direct infection of the heart. The bacteria do not invade the cardiac tissue. It is the immune response itself, intended to protect the body, that causes the damage. This distinction matters because it explains why the damage continues even after the infection has resolved, and why recurrent streptococcal infections cause cumulative, progressive valve injury.
From Strep Throat to Heart Disease, The Disease Pathway
▶ The Progression of Rheumatic Heart Disease
| Stage | What happens | Timeframe | Prevention window |
|---|---|---|---|
| Step 1 | Group A strep throat infection sore throat, fever, swollen glands. Often mild or asymptomatic in young children. | Days | ✓ Antibiotics here prevent everything that follows |
| Step 2 | Acute rheumatic fever joint pain, fever, skin nodules, chorea (involuntary movements), and carditis (inflammation of the heart). Occurs 2–4 weeks after untreated strep infection in susceptible individuals. | 2–4 weeks after infection | ✓ Anti-inflammatory treatment limits cardiac damage |
| Step 3 | Recurrent rheumatic fever each subsequent strep infection triggers another inflammatory attack on already-damaged valves. Damage is cumulative and progressive with each episode. | Months to years | ✓ Penicillin prophylaxis prevents recurrence |
| Step 4 | Chronic rheumatic heart disease scarring, thickening, and calcification of the valve leaflets produce stenosis (narrowing) or regurgitation (leaking), or both. Progressive valve dysfunction leads to heart failure, arrhythmia, and stroke. | Years to decades | Surgery or intervention required at this stage |
| Step 5 | End-stage valve disease severe heart failure, pulmonary hypertension, atrial fibrillation, stroke risk. Without intervention, premature death, often in the third or fourth decade of life. | Decades | Prevention failed, surgical or palliative care only |
How Rheumatic Fever Damages the Heart
Carditis, the acute inflammatory phase
During an episode of acute rheumatic fever, inflammation can affect all three layers of the heart, the pericardium, myocardium, and endocardium. The endocarditis component, inflammation of the inner heart lining and valves, is responsible for the lasting structural damage. Small inflammatory nodules called Aschoff bodies form in the valve tissue. The valve leaflets become swollen and inflamed. In the acute phase, this can cause the valve to leak.
With prompt treatment and no recurrence, this acute inflammation may resolve without lasting damage. But with recurrent episodes, each one adds another layer of scarring, fibrosis, and calcification to the valve structure.
Valve involvement, which valves and how
The mitral valve is by far the most commonly affected, involved in around 65 to 70% of cases of rheumatic heart disease. The aortic valve is the second most frequently affected, either in isolation or, more commonly, in combination with the mitral valve. The tricuspid and pulmonary valves are involved in a minority of cases and rarely in isolation.
Rheumatic damage produces two distinct valve abnormalities, either separately or together. Stenosis occurs when the valve leaflets fuse together along their edges, progressively narrowing the valve opening and restricting forward blood flow. Regurgitation occurs when scarring prevents the leaflets from closing completely, allowing blood to leak backwards. Many patients with longstanding rheumatic heart disease have elements of both.
Mitral stenosis, the signature lesion
Mitral stenosis, narrowing of the mitral valve, is the signature lesion of rheumatic heart disease and is virtually unknown in high-income countries outside this context. As the valve area progressively narrows from a normal 4 to 6 square centimetres toward the critical threshold of below 1.5 square centimetres, blood backs up from the left atrium into the pulmonary circulation.
The consequences are progressive. Breathlessness develops, initially on exertion, then at rest. Pulmonary hypertension follows as the pressure backs up further. Atrial fibrillation becomes increasingly common as the left atrium dilates under chronic pressure overload, and in the context of mitral stenosis, AF carries a very high stroke risk from clot formation in the left atrial appendage. Heart failure follows. Without intervention, the trajectory is relentlessly downward.
This is the disease I see in young adults in Timor-Leste. A 28-year-old with severe mitral stenosis, in atrial fibrillation, breathless at minimal exertion, a picture that is largely absent from Australian cardiology practice but common across much of the developing world.
A Global Burden, and a Local Reality
The scale of the problem
Rheumatic heart disease affects an estimated 40 million people worldwide and causes approximately 300,000 deaths annually, the vast majority in low and middle-income countries in sub-Saharan Africa, South Asia, the Pacific Islands, and Southeast Asia. It disproportionately affects children and young adults in the prime of their lives, in communities that can least afford to lose productive members to preventable disease.
In Timor-Leste, Australia’s nearest neighbour, a country of approximately 1.3 million people that has only had independence since 2002, rheumatic heart disease remains one of the most significant cardiovascular burdens. Limited access to antibiotics for streptococcal infections, overcrowded housing conditions that facilitate strep transmission, and a healthcare system that is still developing its capacity to screen, diagnose, and treat cardiac disease all contribute to a burden that is entirely disproportionate to what should be possible with basic medical resources.
What I saw in Dili
During my time working with the cardiac team at Hospital Nacional Guido Valadares in Dili, the contrast with Australian practice was stark. Patients with valve disease that would have been identified and treated years earlier in Australia. Young people in heart failure from conditions that were preventable with antibiotics costing cents per course. Families who had no idea that a sore throat their child had years ago was the beginning of the heart disease now threatening their life.
The clinical skill and dedication of the local cardiologists working with the resources available to them is remarkable. The limitation is not knowledge or commitment, it is the infrastructure, the medication access, and the surgical capacity that simply does not yet exist within the country.
Mending Broken Hearts
The Timor-Leste Hearts Fund
Australia’s only medical NGO dedicated to life-saving heart surgery and heart health education for young people in Timor-Leste. Founded in 2010, the Fund partners with the cardiac clinic at Hospital Nacional Guido Valadares to screen patients, provide surgery for critical cases in Australia, and build local clinical capacity.
Key programs include penicillin prophylaxis for patients with known rheumatic heart disease, echocardiographic screening, clinical mentorship for local cardiologists, and advocacy for a health system that can one day manage this burden domestically.
Prevention, The Power of a Simple Antibiotic
Primary prevention, treating strep throat
The most powerful intervention in the entire rheumatic heart disease chain is also the simplest: treating streptococcal throat infection promptly with antibiotics. A 10-day course of penicillin, or a single injection of benzathine penicillin G, eradicates the Group A Streptococcus and prevents the abnormal immune response that leads to rheumatic fever.
This is straightforward in a healthcare system with access to diagnosis and antibiotics. In settings without reliable access to either, it is the gap through which millions of lives fall.
Secondary prevention, penicillin prophylaxis
For individuals who have already had acute rheumatic fever, preventing recurrence is the most important priority. Every subsequent streptococcal infection risks triggering another inflammatory attack on already-damaged valves. Long-term penicillin prophylaxis, typically monthly injections of benzathine penicillin G, prevents this recurrence and halts the progressive valve damage.
The Timor-Leste Hearts Fund’s penicillin prophylaxis programme is one of its most impactful initiatives, identifying patients with known rheumatic heart disease and ensuring they receive their monthly penicillin, protecting already-damaged valves from further deterioration. The cost of this intervention is minimal. The benefit to an individual’s cardiac trajectory is enormous.
Echocardiographic screening
One of the most significant advances in rheumatic heart disease management has been the recognition that echocardiography can identify subclinical rheumatic valve disease, damage that is present but not yet producing symptoms, in populations with high rheumatic fever rates. Screening programs in endemic regions can identify patients who would benefit from prophylaxis before their disease becomes clinically significant. The Fund supports this screening capacity at the National Hospital in Dili.
Treatment, When Prevention Has Failed
Medical management
For patients with established rheumatic heart disease, medical management focuses on controlling symptoms, preventing complications, and protecting against further rheumatic fever episodes. Diuretics manage fluid overload in patients with stenotic valves. Anticoagulation is essential in patients with mitral stenosis and atrial fibrillation to prevent stroke. Rate control for AF reduces symptoms and prevents further cardiac remodelling. Penicillin prophylaxis continues throughout.
Valve intervention
When rheumatic valve disease becomes haemodynamically significant, producing severe symptoms, pulmonary hypertension, or significant cardiac dysfunction, valve intervention is required. The options depend on the anatomy of the damage.
For mitral stenosis without significant regurgitation, percutaneous mitral balloon valvotomy, a catheter-based procedure that splits the fused leaflets, can produce excellent results and restore the valve to a functional state without open heart surgery. For more complex valve lesions, or when regurgitation is significant, surgical repair or replacement is necessary.
For patients in Timor-Leste who reach the threshold for surgical intervention, the Timor-Leste Hearts Fund coordinates their transfer to Australian hospitals where the surgery is performed, in many cases giving a young person a functional heart valve and decades of additional healthy life. The contrast between the trajectory without intervention and the outcome with it is one of the most dramatic in all of medicine.
Sitting in the outpatient clinic in Dili, seeing a 24-year-old woman with severe mitral stenosis, breathless climbing one flight of stairs, in AF, with a left atrium the size of a tennis ball, knowing that the strep throat she had at twelve years old caused all of this, and that a course of antibiotics would have prevented it entirely: that is the injustice of rheumatic heart disease in one consultation. The clinical complexity of what she now needs is significant. The simplicity of what would have prevented it is almost unbearable.
— Prof. Peter Barlis, Interventional Cardiologist & Board Member, Timor-Leste Hearts Fund
What You Can Do
Awareness is the first step. Rheumatic heart disease is not a condition confined to history or to distant countries, it is affecting millions of people right now, including young people in our own region, in communities without access to the medical infrastructure we take for granted.
For clinicians in high-income countries, particularly those seeing patients from endemic regions, maintaining a high index of suspicion for rheumatic valve disease in patients from sub-Saharan Africa, Southeast Asia, the Pacific Islands, and South Asia is important. A murmur in a young adult from an endemic region is rheumatic until proven otherwise.
For anyone who wants to make a direct contribution to changing the trajectory of this disease in one of our nearest neighbours, the Timor-Leste Hearts Fund offers a direct and efficient pathway to do so.
- Caused by Group A Streptococcus, the same bacteria as strep throat, via an abnormal immune response in susceptible individuals.
- Affects an estimated 40 million people worldwide, predominantly in low and middle-income countries.
- The mitral valve is most commonly affected, followed by the aortic valve.
- Entirely preventable with prompt antibiotic treatment of strep throat and penicillin prophylaxis after rheumatic fever.
- In Timor-Leste, the Timor-Leste Hearts Fund coordinates life-saving surgery, penicillin prophylaxis, screening, and clinical training.
Heart Matters Resource
When in Doubt, Get Checked Out
If you have a history of rheumatic fever, particularly if you grew up in a region where streptococcal infections were common and access to antibiotics was limited, a cardiac assessment including echocardiography is worth discussing with your doctor. Rheumatic valve disease detected early can be managed to protect against further deterioration.
Conclusion
Rheumatic heart disease is the story of what happens when a preventable infection meets a healthcare system that cannot prevent it. The biology is well understood. The prevention is simple and cheap. The tragedy is one of access and equity, not of medical complexity.
Every course of antibiotics given to a child with strep throat in an endemic region is an act of cardiovascular prevention. Every monthly penicillin injection given to a young person with known rheumatic fever is a valve being protected from further damage. Every echocardiogram that identifies subclinical disease is a life being redirected away from the trajectory that brought so many patients to that clinic in Dili.
The Timor-Leste Hearts Fund is doing this work, with remarkable efficiency, with remarkable dedication, and with the kind of direct impact that is rarely achieved in global health. If this article has raised your awareness of rheumatic heart disease, and if you are moved to support the work that is being done to address it in our region, I would encourage you to visit the Fund’s website and find out how.
