About Tapeworms in Humans

Tapeworm infection in humans (called taeniasis) is rare. It is usually the result of eating undercooked meat or fish. Often there are few or no symptoms, but certain types of tapeworms can cause serious complications. Typically, the tapeworm eggs are ingested and then grow into larvae in the intestines. A fully grown adult worm can reach a length of 15 to 30 feet. The best way to avoid contracting tapeworms is to properly cook food and to practice good hygiene and hand washing.

Causes

• Tapeworm infection is the result of eating meat that has not been properly cooked. Different species of tapeworm come from different types of meat. Taenia saginata comes from beef, Taenia solium comes from pork, and Diphyllobothrium latum comes from certain types of freshwater fish. The tapeworms from beef and pork can be as long as 30 feet. The pork tapeworm Taenia solium can be passed from human to human if there is contact with the feces of an infected person. This can happen by ingesting contaminated food or water, or by touching contaminated surfaces such as furniture or clothing and then touching your mouth.

Symptoms

• Most people with tapeworms show no physical symptoms. The diagnosis of tapeworm infection, called taeniasis, usually occurs when a doctor examines a patient's stool and finds proglottids (worm segments) or eggs. Occasionally, a patient may suffer from upper abdominal discomfort, appetite loss and diarrhea. Some patients see worm segments in their stool or feel the movement of the tapeworm moving out through the anus.

Complications

• The larvae of the pork tapeworm, Taenia solium, can cause a condition called cysticercosis, the creation of cysts in different parts of the body. The larvae break through the wall of the intestines and travel to the muscles, organs or even the brain. The cysts they cause, depending on their location, can result in further complications, such as seizures, heart problems and even decreased vision or blindness. People who contract the fish tapeworm can become anemic, because Diphyllobothrium latum absorbs vitamin B-12, which allows red blood cells to mature.

Cure

• Generally, a single dose of an oral medication is used to treat taeniasis. Niclosamide, praziquantel and albendazole are some medications that may be used. Unless the brain is infected, cysticercosis is usually left untreated. A doctor may prescribe a medication to deal with side effects, such as inflammation.

Prevention

• The National Institutes of Health (NIH) says that tapeworm infection is rare today because of food and animal care regulations. Still, it is important to thoroughly cook meat to a temperature of at least 135 degrees Fahrenheit. Also, freezing meat for a long time can lower the chances of contracting tapeworms. Avoid eating sushi made from freshwater fish. Finally, practice good hygiene to avoid contracting taeniasis from an infected person.