My aunt has a tapeworm when she was in her middle 20's. She lives in Germany and it was in the late 1950's when it happened. She got really skinny. Back then the doctor suspected the problem. She was put on a strict diet of salted herring. Apparently, these parasites can't tolerate the excess salt and it came out after about a week or so.

It was a scary event from what she told me. The tapeworm was very large. I think tapeworms are pretty rare, but it is possible.