I can certainly see how this is likely to be a science book. With the latest photographic technology scientists have photographed everything from star nebulas, space gases, to exoskeletons of creatures, flowers, sun flares, waves in motion, inside cells, etc. so yes absolutely!
The answer is penicillin
Rheumatic fever is a disease that caused by Group A streptococcus infection. The bacteria has component that similar to the heart valve cells, makes the immune cell attack it. The drug of choice for this infection is penicillin G benzathine injection. It is one of penicillin family drug that has high prevalence of allergy reaction, so you must be aware.