Found in cold climates in North America and Europe, “tapeworms can live and grow in us for a while before we notice there’s a problem,” says DeWitt. Broad tapeworms, the largest variety of tapeworms that infect humans, can grow up to 20 feet long. That’s long enough to protrude from an infected person’s anus! They live in the muscles of trout, salmon, pike, walleye, northern pike and sea bass, among other species, and are commonly ingested when they’re larvae and too small to see with the naked eye. From there, they attach to the small intestine and grow and grow.
Most people don’t have any symptoms of tapeworm infection at all, although they can eventually cause weight loss, B-12 deficiency, anemia, nausea, vomiting, weakness, dizziness, diarrhea and abdominal swelling. It’s essential to cook fish because cold smoking, marinating and pickling may not be enough to kill the intruder. If you are infected, anti-parasite drugs will kill the parasite.
Up Next: This type of parasite is found on fish in local rivers and streams.