Taenia solium

The pork tapeworm.

Contracted from eating undercooked or measly pork (pork infected with the larval forms of the tapeworm).

Taenia solium causes two different diseases -- taeniasis and cysticercosis.

Taeniasis develops when the adult tapeworm infests the human intestine.

The worm can grow to be 3-6 feet (0.9-1.8 m) long there.

It usually causes no symptoms but the host becomes a continuous source of taenia eggs in the feces which may contaminate food.

Cysticercosis develops when people (or pigs) eat food contaminated with taenia eggs.

The eggs cross the digestive tract, enter the circulation, and lodge in the tissues (usually the brain or muscles).

The life cycle proceeds as humans ingest undercooked pork containing the cysticercus (larva); the worm emerges and anchors in the intestinal wall, and the worm grows and becomes a new and continuous source of contamination.

Also known as the armed tapeworm, solitary tapeworm and the measly tapeworm.

Synonyms include Taenia armata and Taenia dentata.