Adult tapeworm infection is the infection of the digestive tract by parasitic flatworms called cestodes or Woods. Live tapeworm larvae are sometimes ingested by consuming undercooked food. Once inside the digestive tract, the larva grows into an adult tapeworm, which can live for years and grow very large.

Among the most common “tapeworms” in humans are the pork tapeworm, the beef tapeworm, the fish tapeworm, and the dwarf tapeworm. Infections involving the pork and beef tapeworms are also called taeniasis. Tapeworms of the genus Echinococcus also infect animals and humans, and cause the most harm to intermediate hosts such as sheep and cattle. Infection with this type of tapeworm is referred to as Echinococcosis or hydatid disease.

Tapeworm Symptoms vary widely, as do treatment options, and these issues are discussed in detail in the individual articles on each worm. With a few notable exceptions like the fish tapeworm, most cestodes that infect humans and livestock are cyclophyllids, and can be identified as such by the presence of four suckers on their scolex or “head.”

Tapeworm infection usually occurs when you eat food or drink water contaminated with tapeworm eggs or larvae. Most people infected with tapeworm are unaware they’re carrying them. Tapeworms occur in humans in one of two forms. If ingested as eggs, they may develop into larvae that migrate out of the intestines and form cysts in other tissues such as the lungs or liver. These cysts can cause serious problems. Or, if ingested as larvae, they typically develop into adult tapeworms in the intestines, which usually cause few or no symptoms.

The good news is that you can help prevent tapeworm infection with good personal hygiene, such as washing your hands before eating, and avoiding eating raw or undercooked meats.

If you experience any of the signs or symptoms of tapeworm infection, you should seek medical attention. Also contact your doctor if you believe you’ve been exposed to food or water contaminated with tapeworm.