The Six Phases of a Tapeworm

The parasitic tapeworm that infects humans gets its names because of its long, thin, tape-like body. The infection can be passed from a human carrier to livestock and then back to other humans. The passage of this disease is through fecal matter that contaminates food of people or animals.

Fecal Matter

• Tapeworm eggs are found in fecal matter from an animal or person infected with tapeworms. Tapeworms in the infected individual lay eggs in the intestine which are excreted when the individual defecates. The eggs are then passed into the environment, usually by decomposition of the fecal matter. Vegetation fertilized with infected fecal matter from an animal, such as a cow or pig, will be contaminated with the tapeworm eggs. This vegetation can include grass or livestock feed as well as vegetables that are grown for human consumption.

Contaminated Vegetation

• Contaminated food is ingested with the tapeworm eggs on it by pigs or cows. By ingesting the tapeworm eggs, the pig or cow is infected with the tapeworm parasite. The eggs go through most of the digestion process of the animal. The eggs then settle in the intestine of the pig or cow.

Hatching

• Tapeworm eggs hatch in the intestines of the infected animal. This hatched stage of the tapeworm is called an oncosphere. The oncospheres penetrate the intestine wall and move to other organs, such as the brain, liver, tissues and striated muscles. Once the oncospheres have migrated to other organs, they turn into cysts. Infected animals with no signs of disease may then be slaughtered and prepared for human consumption, allow for transmission of the parasite.

Undercooked Meat

• Humans who eat undercooked pork or beef contaminated with oncosphere cysts get infected with the tapeworm. The cysts found in the undercooked meat travel to the intestines of the infected human through the normal digestion process. The intestines are where the cysts stop in the human system.

Cysts Attach to the Intestine

• Cysts turn inside-out, causing the insides of the cysts to protrude in a tubular fashion. These inside-out cysts attach themselves to the small intestine of their human carrier by their scolex, or head-like segment.

Adult Tapeworms

• Adult tapeworms develop off the scolex that is attached to the intestine wall. Adult tape worms can grow to between 6.5 and 23 feet long with up to 1,000 segments. Each segment has its own reproductive system containing 50,000 eggs. Adult tapeworms can live for years in a human carrier if the tapeworm infection is not diagnosed and cured.