I got this one right but it was a guess- basically Penicillin is conventional treatment for Rheumatic Fever and the point they are trying to make is that if you don't prevent another infection there is a chance of reoccurence... the more times one has RF the more valvular damage they can get. They said in the detailed response that while treatment time is questionable many will use prophylactic penicillin until age 18... so really this isn't them treating the disease it is preventing further damage (kind of like the need to prophy peds patients after splenectomy for encapsulated bacteria usually til 18 as well).
