A cousin had rheumatic fever 3 times: at age 9, 18 and again in her late 20s. The first time she was so ill that she had to be treated at home, the GP thought that a journey to Hospital 88 miles away would kill her. We all crept about for weeks.
Thanks Machair - how old were you when the virus struck? Like many of these types of conditions, they can remain dormant. Stress, tiredness, worry can bring them out. The other one that springs to mind is herpes from Chickenpox = shingles which comes out when someone has an accident or shock.