It is the end of summer vacation and a 10-year-old girl is outside playing when her mother notices the jerky and uncontrolled movements of her usually coordinated daughter. Earlier in the summer the girl had complained of a sore throat and later she had shown a skin rash for a day or two. When the girl said that her knee ached, her mother dismissed these complaints as "growing pains." Could these simple ailments be connected? This young girl is showing symptoms of rheumatic fever, a disease that usually affects young people aged five to 15 and girls more frequently than boys. Symptoms often manifest themselves in late summer or early fall if a child has had a throat infection in the spring or early summer.

The disease begins as a bacterial infection such as strep throat caused by Group A streptococcus bacteria. To combat the infection, the...