Rheumatic heart disease most often follows infection with which organism?

Rheumatic heart disease most often follows infection with which organism?

• A. Streptococcus pneumoniae
• B. Staphylococcus aureus
• C. Enterococcus faecalis
• D. Streptococcus pyogenes

Answer: (D)

Rheumatic heart disease results from an immune reaction that follows an infection with a group A Streptococcus. When the throat is infected by Streptococcus pyogenes, the body makes antibodies against the bacterial M protein. Some of these antibodies cross-react with cardiac tissue, especially the heart valves, triggering inflammation that can damage the valves over time. This autoimmune process is why rheumatic fever can lead to chronic rheumatic heart disease, most often affecting the mitral valve. Streptococcus pneumoniae typically causes respiratory infections like pneumonia and otitis media, not a post-infectious autoimmune heart disease. Staphylococcus aureus is a common cause of skin infections and acute infective endocarditis, but it does not trigger the rheumatic autoimmune reaction. Enterococcus faecalis is associated with various infections and endocarditis, again not the post-streptococcal rheumatic mechanism.

Rheumatic heart disease results from an immune reaction that follows an infection with a group A Streptococcus. When the throat is infected by Streptococcus pyogenes, the body makes antibodies against the bacterial M protein. Some of these antibodies cross-react with cardiac tissue, especially the heart valves, triggering inflammation that can damage the valves over time. This autoimmune process is why rheumatic fever can lead to chronic rheumatic heart disease, most often affecting the mitral valve.

Streptococcus pneumoniae typically causes respiratory infections like pneumonia and otitis media, not a post-infectious autoimmune heart disease. Staphylococcus aureus is a common cause of skin infections and acute infective endocarditis, but it does not trigger the rheumatic autoimmune reaction. Enterococcus faecalis is associated with various infections and endocarditis, again not the post-streptococcal rheumatic mechanism.