Yikes. Scientific American reports that tapeworms may be on the rise in urban areas--including Chicago, where a man filed suit last year against Shaw’s Crab House for allegedly serving him undercooked salmon in 2006; he later passed a nine-foot tapeworm (a restaurant spokesperson denied that the tapeworm came from Shaw's). According to the article, hospitals in Japan are reporting an increasing number of cases of salmon tapeworms, "mostly among yuppies with a hankering for sashimi and ceviche," as well as North America and Europe. And rising urban fox populations in Europe are causing fox tapeworms to become a problem; they cause a fatal liver disease in humans. (Maybe it’s time to stop joking that I have a tapeworm, which I’ve been doing for years to explain why I always seem to be hungry.)
On an interesting side note, I remember seeing in a museum once that women in the early 20th century used to ingest tapeworms as a weight-loss method. A quick Google search reveals that not much has changed: though it's now illegal in the U.S., there are still people selling beef tapeworms (supposedly the safest kind) as a diet method, some for over $1,000 per treatment. I think Diets in Review sums up the potential benefits of using tapeworms for weight loss pretty well with the first two entries on its pro/con list: "Pro: Weight loss is pretty much guaranteed . . . Con: Can be deadly."
(I looked for tapeworm images to include with this post and decided not to put one in. You're welcome.)