Acute rheumatic fever (ARF), a disease of poverty, is an auto immune reaction occurring after infection with Lancefield Group A β-hemolytic streptococci. It is commonly found in areas where the standard of hygiene is low and overcrowding is present. However its incidence in developed countries has decreased due to better living condition and high level of sanitation, along with development of potent antibiotics and better medical care; which has helped reduce the transmission of β-hemolytic streptococci.
Although it affects all the parts of the body including heart (cardiac), CNS (Central Nervous System), joints, skin; almost all of the manifestations resolve completely, with the exception of heart valvular lesions, which may persist after the other features have disappeared. And this Rheumatic heart disease (RHD) is a major cause of cardiac related mortality and morbidity in the developing countries.
Incidence of ARF is common in children aged 5–14 years. It is rare in persons aged >30 years. By contrast, recurrent episodes of ARF remain relatively common in adolescents and young adults. But, prevalence of RHD peaks between 25 and 40 years.