Rheumatic fever is an inflammatory disease that can happen after a person becomes infected with the Streptococcus bacteria.
Rheumatic fever was once a common cause of heart problems in childhood. It remains a serious childhood health problem in many developing countries. In North America, it's become much less common due to improved hygiene and routine use of antibiotics for infections. When it does strike, however, it can still have serious consequences for heart health.
Rheumatic fever is most frequent in children aged 5 to 15 years old, but can also affect adults and children younger than 5 years of age. However, there are no reliable figures on adults.