Tapeworm Causes & Risk Factors

Tapeworms are flat segmented worms that live in the intestine. These intestinal parasites can live as long as 20 years inside a host's body. Most tapeworm infestations are mild and cause few symptoms, and they are generally easy to treat with de-worming medications. Severe cases, however, can result in life-threatening complications for the host.

Tapeworm Causes

• According to mayoclinic.com, most tapeworm infections in humans are caused by eating undercooked meat or freshwater fish. People ingest the eggs or larvae of parasites such as the beef tapeworm Taenia saginata, the fish tapeworm Diphyllobothrium latum, the dwarf tapeworm Hymenolepis nana, and Taenia solium, which is a tapeworm commonly found in pork. Infested animals have small pockets of larval tapeworms called cysts in their muscle tissue. People who eat undercooked pork, freshwater fish or beef ingest the tapeworm larvae, which grow into adult tapeworms in the intestinal system. The tiny adult dwarf tapeworm is approximately 2 inches, while adult pork and beef tapeworms are between 15 and 30 feet long. Adult fish tapeworms can be more than 30 feet in length.

Risk Factors

• In addition to eating raw or undercooked meats, people who work with animals or who are frequently exposed to their fecal leavings are at risk of tapeworm, particularly if the feces are not properly disposed of. Frequent travel to underdeveloped countries or countries with poor sanitation practices can also increase the risk of tapeworm infections. Other risk factors include not washing hands before eating or after using the toilet, and eating food or drinking water that has been contaminated by the fecal remains of infected animals.

Health Risks

• Most people who are infected with tapeworms have no symptoms, although some individuals may have some slight stomach pain or appetite loss. Sometimes the proglottids, which are small flat pieces of tapeworm containing eggs, can be seen in the stool.

  People with fish tapeworm sometimes suffer from anemia because the worm absorbs vitamin B12, which is necessary for the development of red blood cells. The beef and dwarf tapeworms rarely cause any serious damage, but the pork tapeworm uses the human body as an intermediary host where the larvae reside while they wait for someone or something else to infect. The eggs hatch into larvae and travel into parts of the body such as the brain, lungs, muscles or tissue below the skin, where they form larval cysts. They cause diseases and disorders like meningitis, headaches, blindness and dementia if they enter the brain; they can damage vital organs, rupture blood vessels or slow down circulation if they enter other areas of the body. Surgery or organ transplants are often necessary to prevent death.