During my undergraduate years, I spent two semesters in New Zealand. I met some pretty interesting people – one of whom was my flat mate. As we got to know each other, I came to understand that she loved running and playing soccer but was unable to participate sometimes due to a childhood illness. Being the foreigner, I was too afraid to ask and thought that someday maybe she would feel comfortable enough to talk about it. As time progressed, and soccer tryouts commenced, she was not able to participate because she was having a particularly annoying and untimely bout of angina – chest pain. I of course, assumed the worst; is this healthy, nineteen year old woman having a heart attack? As I expressed my concern, she informed me that she had scarlet fever as a child.
Still not knowing much about scarlet fever, I was intrigued to the point of investigation. I took to the Internet and found some very interesting facts about scarlet fever and rheumatic heart disease. Rheumatic fevers are caused by the same bacteria that cause strep throat – a group A beta hemolytic streptococcal infection. Failure to receive proper treatment following a streptococcal infection may result in the development of rheumatic fever and its very serious side effects, namely rheumatic heart disease. The pathophysiology is not fully understood, but it is presumed that there is an autoimmune response to cardiac antigens that look very similar to the strep A antigens, causing damage to the heart.
Check out the clinical manifestations of rheumatic fever in this YouTube video:
What is known about rheumatic fever is that it only occurs after a Step A infection of the throat, or a “reactivation” of the fever. The bacteria attach to the epithelial cells of the throat and release a cocktail of enzymes that cause local tissue damage. After 2-4 days an immune response is mounted for 3-5 days with the most common symptoms being fever, malaise, headache, and elevated leukocyte count. Subsequently, development of rheumatic fever may follow within 3 to 4 weeks if the infection is not treated properly. The streptococcal “M protein” has similar antigens to that of the human heart – most commonly the glycoproteins located on the valves of the heart. In other words, the body’s immune system over time gets “confused” about what is the strep A bacteria and what is “self” – it therefore unwittingly attacks the valves of the heart causing serious damage.
Rheumatic fever usually only affects children from the ages of 5 to 15 and is not common in developed countries. In spite of this, rheumatic fever is still the leading cause of acquired heart disease in children within these developed countries. On a global scale, it is estimated that 5-30 million children have chronic rheumatic heart disease and that 90,000 patients die annually from this disease. Rheumatic heart disease also accounts for 99% of mitral valve stenosis, with varying severity, in adults.
Although we live in a country where 0.05 cases per 1,000 individuals are diagnosed with rheumatic heart disease annually, there is some concern among medical professionals that due to the increasing penicillin resistance among streptococcal species, this number may show a statistically significant increase in the coming years. However, in developing countries, rheumatic heart disease already has a very significant effect on young people, is often neglected, and completely preventable.
Check out this YouTube video to see how rheumatic heart disease is viewed throughout the rest of the world.