Which are the causes of Rheumatic Fever?

Rheumatic fever is an inflammatory condition caused by an abnormal immune response to an untreated or inadequately treated infection with Group A streptococcal bacteria, such as strep throat. While the infection itself is bacterial, rheumatic fever is considered an autoimmune reaction where the body's immune system mistakenly attacks its own healthy tissues, particularly in the heart, joints, brain, and skin.

What exactly causes Rheumatic Fever?

The primary cause of rheumatic fever is a delayed and exaggerated immune response to a pharyngeal infection caused by Group A Streptococcus (GAS). It is not a direct infection of the heart or joints; rather, it is a form of molecular mimicry. The immune system creates antibodies to fight the strep bacteria, but because some bacterial proteins resemble proteins found in human tissues, the antibodies accidentally target the body’s own heart valves and joints.

Are there genetic or environmental risk factors?

While rheumatic fever is not inherited in a simple Mendelian pattern, research suggests a genetic predisposition. Certain human leukocyte antigen (HLA) types may make some individuals more susceptible to the autoimmune reaction. Environmental factors remain the strongest drivers, particularly in resource-limited settings where overcrowding and limited access to antibiotics for strep throat increase the risk of rheumatic fever developing.

What are the primary triggers for development?

• Untreated Strep Throat: Failure to clear the initial Streptococcus pyogenes infection is the most critical trigger.


• Host Immune Susceptibility: A specific, albeit complex, genetic tendency to overreact to bacterial antigens.


• Socioeconomic Environment: Factors like crowded living conditions that facilitate the rapid spread of Group A streptococci.


• Recurrence: Individuals who have had rheumatic fever once are significantly more likely to develop it again if they contract another strep infection.

Is the etiology of Rheumatic Fever fully understood?

While the link between GAS and rheumatic fever is well-established, scientists are still researching why only a small percentage of people who get strep throat go on to develop the condition. Ongoing studies focus on identifying specific bacterial strains that are "rheumatogenic" and mapping the precise genetic markers that signal an individual is at high risk for rheumatic fever complications.

Next steps

• Consult your primary care physician immediately if you experience a sore throat accompanied by a high fever.


• Ensure that any diagnosed strep throat infection is treated with a full course of antibiotics as prescribed.


• Connect with the 11 community members on DiseaseMaps.org who are navigating life with rheumatic fever.


• Discuss long-term secondary prophylaxis (preventative antibiotics) with a specialist if you have a history of the condition.

Medical disclaimer: This content is for educational purposes only and does not constitute professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Rheumatic Fever


• Orphanet: Rheumatic Fever (ORPHA:792)


• World Health Organization (WHO): Rheumatic Fever and Rheumatic Heart Disease Fact Sheets


• American Heart Association: Prevention of Rheumatic Fever and Diagnosis and Treatment of Acute Streptococcal Pharyngitis