Rheumatic fever is caused by certain strains of streptococcal bacteria. A strep throat infection that isn't properly treated can trigger rheumatic fever. Rheumatic fever can damage heart muscle and heart valves. Not all people who have rheumatic fever develop rheumatic heart disease.
How does rheumatic fever damage the heart?
This infection causes swelling and muscle damage to the heart. It can also damage the heart valves in a way that keeps the blood from moving through the heart normally. The infection can cause heart valve leaflets to stick together, which narrows the valve opening. Also, the infection can scar the valves. This keeps the valves from closing tightly, so blood leaks backward in the heart.
Who is affected by rheumatic fever?
Rheumatic fever is rare in Canada, the United States, and western Europe. But it was fairly common until the 1950s. Widespread use of antibiotics to treat strep throat has greatly lowered the number of new cases of rheumatic fever.
Today, most rheumatic fever cases occur in developing countries, particularly Africa and southeast Asia.
Some people may develop a heart valve disease after having rheumatic fever as a child. It might take a few years to 20 years or more after a case of rheumatic fever for a valve problem to develop.