Cysticercosis: An infection caused by the pork tapeworm, Taenia solium. Infection occurs when the tapeworm larvae enter the body and form cysts called cysticerci. When cysticerci are found in the brain, the condition is called neurocysticercosis. Cysticercosis is contracted by accidentally swallowing pork tapeworm eggs. Tapeworm eggs are passed in the bowel movement of a person who is infected. When the tapeworm eggs are inside the stomach, they hatch, penetrate the intestine, travel through the bloodstream, and may develop into cysticerci in the muscles, brain, or eyes. Infection is found most often in rural, developing countries where hygiene is poor and pigs are allowed to roam freely and eat human feces. Cysticercosis is not spread from person to person. However, a person who is infected with the intestinal tapeworm stage of the infection (T. solium) sheds tapeworm eggs in bowel movements. Tapeworm eggs that are accidentally swallowed by another person can cause infection.