When I was young I passed tapeworm on a couple of occasions, and was too scared to tell my parents or doctor.
I have read that they can live in the body unknown for years and cause serious problems if they get into major organs.
I have been fine for at lease 12 years but am now worried that they may be in there... should I be concerned?
No, lots of kids get tapeworms, and pass them as you did. Since you are healthy, I wouldn't worry. My sister did this when she was just a little girl, but our parents just didn't care. She's 53 and very healthy today, and has never had any other problems with them. Relax...........