What are the chances of an average american person getting an internal parasite such as a tapeworm?

Rare but happens: With our mandated inspection of meat production facilities, the U.S. Has nearly eliminated tapeworms and other intestinal parasites. You can still get them, particularly from eating wild game and fish. It's always a good idea to thoroughly cook any wild meat and fish. Thanks to david miller for his answer.

Parasites common but: Intestinal parasites are common but tapeworms are rare in the US. Relatively benign worms like pinworms,roundworms and liver flukes are more common but are difficult to diagnose. More common than worms are single-celled protozoa like Blastocystis hominis and amoeba. About 20% of people have B. hominis and probably at least 1/3 of Americans have parasites, but most are not that serious.See comment: