Diseases from Tapeworms

Tapeworms are parasites that attach to the intestines of their hosts and live there for some time. Three species of tapeworms cause human disease. They normally do not cause serious symptoms; however, taenia solium tapeworms may travel to the brain and cause neurological disease. Tapeworm infections are easily treatable. Perhaps the most startling thing about tapeworms is the fact that they can grow up to 20 meters long. (Yes, that's a 12-inch ruler on the image above.)

Parasites

• Parasites can be acquired through an insect bite, contaminated water or contaminated food. Many types of organisms can be classified as parasites, from simple viruses to the more complex tapeworms.

Tapeworms

• Tapeworms are parasites found in the digestive tract of vertebrates and are acquired when the host ingests eggs or larvae. The tapeworms then mature inside the host and attach themselves to the host's intestines via its scolex (head), which is equipped with either suckers or hooks. Some tapeworms may migrate out of the digestive tract and into other parts of the body causing more severe disease. As the tapeworms grow inside the host's intestine, they release eggs that are passed by the host, continuing their life cycle.

Taenia saginata

• Taenia saginata is a tapeworm that infects cattle. Humans become infected when the cattle passes tapeworm eggs in its stool and the eggs are ingested by humans. Rarely, humans may become infected when they eat contaminated beef. This is because the tapeworm eggs may hatch inside the cattle and travel to the muscles, becoming inclusions called cysticercus. Current quality controls on commercial beef and proper cooking of meat prevent the cysticercus from surviving to infect consumers of the contaminated beef. Infection with T. saginata causes abdominal discomfort in the majority of cases and sometimes will cause diarrhea or bloody stools. The infection is easily treated with antiparasitic drugs. T. saginata tapeworms may reach 5 meters (about 15 feet) in length.

Taenia solium

• Taenia solium is a tapeworm that infects pigs, and humans become infected from passed eggs or by consuming contaminated meat. The T. solium tapeworm may reach 2 to 7 meters (6 to 20 feet) in the intestine. T. solium cysticerci are more dangerous to humans since they are capable of migrating to the brain, a condition called cysticercosis. This is the main cause of acquired epilepsy in the world, according to the Centers for Disease Control and Prevention. As with other neurological diseases, neurocysticercosis causes changes in behavior, confusion and headaches. Rarely, the cysticerci may travel into the eye and cause damage to the retina.

Diphyllobothrium latum

• Diphyllobothrium latum tapeworms are different from the Taenia species in that they are found in fish and fresh water crustaceans. When humans eat infected fish, the D. latum eggs are ingested and they mature in the intestine. Like with T. saginata, infection with D. latum causes abdominal discomfort, with a few cases causing diarrhea. There have been documented cases of people with D. latum who show vitamin B12 deficiency as the tapeworm prevents absorption of the vitamin by the host. D. latum tapeworms are the largest, measuring up to 20 meters (over 60 feet).