The U.S. Centers for Disease Control say tapeworm infection has doubled in frequency within the past 10 years. This is most likely due to the consumption of undercooked beef. Fleas have been known to carry tapeworms, so it's possible to get them if you have pets. Hookworms can be contracted just from walking barefoot on infected soil. They can actually block the intestines.
Roundworm infection is abundant in meat-eating cultures.
One type of flatworm, a fluke, can live very comfortably in the instines, liver, lungs or blood. Trichina is a very tiny worm infecting pigs. The larve, after burrowing into the intestinal wall, enters blood vessels. The blood then carries the larve to muscle fibers where these worms live and grow. Parasites out rank cancer as the number 1 killer in the world today according to experts.