Rheumatic Fever

Description

• Acute rheumatic fever (ARF) is an autoimmune, inflammatory response to infection with group A Streptococcus (GAS) that affects multiple organ systems.
• Untreated acute disease can lead to chronic rheumatic heart disease (RHD).
• Recurrence is common without adequate antibiotic treatment.

Pediatric Considerations
Most cases occur in children aged 5 to 15 years; rare in children aged <5 years

Epidemiology

• ARF and RHD are largely restricted to low-income countries and marginalized sections of wealthy countries.
• Male = female; females more likely to develop chorea and RHD.
• Endemic regions include South Pacific, indigenous populations of Australia and New Zealand, Africa, and Asia (1).

Incidence

• Worldwide, incidence has been declining for 25 years. The large majority of new cases are in developing countries (1).
• Mean worldwide incidence ranges from 8 to 51/100,000 school-aged children; in endemic regions, prevalence can be >1,000 cases per 100,000 people (1).
• Incidence of ARF in the United States is currently <3.4 to 2/100,000 school-aged children (1).

Prevalence

• In developing areas, RHD affects >33 million people and is the leading cause of cardiovascular death during the first 5 decades of life.
• Prevalence has been rising due to improved medical care and longer survival.

Etiology and Pathophysiology

• ARF most commonly occurs 2 to 3 weeks after GAS pharyngitis infection, but GAS impetigo may also be a proceeding infection.
• Although pathogenicity is not completely understood, expert consensus implicates genetic and molecular mimicry leading to an inflammatory cascade as key to disease development.
• Immune cross reactive response contributes to joint involvement due to accumulation of immune complexes.

Genetics

• Susceptibility is associated with certain indigenous populations.
• ARF is heritable, polygenic, and displays variable and incomplete penetrance.

Risk Factors

Poverty, household crowding, genetic susceptibility, ethnic predisposition, and social disadvantage are the strongest risk factors.

General Prevention

• Primary prevention: Appropriate treatment of streptococcal infection prevents ARF in most cases.
• Secondary prevention: long-term antibiotic prophylaxis (up to 5 to 10 years) to prevent recurrence (1)