Tape Worms in Humans

Most people infected with a tapeworm aren't aware that there is a parasite living in their intestines. A tapeworm infection in the intestines is easily treated and rarely has serious health consequences. However, in rare instances, tapeworm larvae can migrate to other organs in the body, creating an infection that can be life-threatening.

Personal hygiene, washing your hands before eating and not consuming raw or undercooked meats will prevent almost all instances in which a human would be infected by a tapeworm.

Species

• Tapeworm infections in humans are most often caused by one of four species. They consist of: the pork tapeworm -- Taenia solium; the beef tapeworm -- Taenia saginata; the dwarf tapeworm -- Hymenolepis nana; and the fish tapeworm -- Diphyllobothrium latum.

Ingestion

• Infection of tapeworms in humans usually occurs when you eat tapeworm eggs or larvae. Eggs are usually ingested through consuming food or water that has been contaminated by human or animal feces. Infection can also occur by ingesting the tapeworm's larvae cysts in meat or muscle tissue. This usually occurs if the meat is eaten raw or undercooked.

Infection

• Once the eggs or larvae are ingested, the larvae migrate to the intestines and form cysts in other tissues, such as the lungs and liver. The larvae develop into adults in your intestines. An adult tapeworm can be 50 feet long and survive for up to 20 years. In many species of tapeworms, the adult attaches itself to the walls of the intestines and with other species, the tapeworm passes out of the body through the stool.

Symptoms

• In many cases, if you are infected with a tapeworm, you will have no symptoms. Symptoms that could occur include nausea, weakness, loss of appetite, abdominal pain, diarrhea and weight loss. If you have an invasive infection, during which the larvae have move out of the intestines and are forming cysts in other tissues of your body, you may have more severe symptoms including fever, cystic masses or lumps, allergic reactions, bacterial infections and possibly even neurological symptoms or seizures.

  You may notice segments of the tapeworm in your stool.

Diagnosis

• If you suspect that you are infected with a tapeworm, make an appointment with your physician. You doctor will take a stool sample for microscopic identification of tapeworm eggs and segments. Your doctor may also wish to do blood testing and possibly do some imaging if there is suspicion the infection may be tissue-invasive.

Treatment

• Treatment will involve prescription medications that are designed to kill intestinal parasites. These may include praziquantel, albendazole or niclosamide. These medications will kill the tapeworm, but not eggs. Proper sanitation is especially important following treatment to ensure re-infection doesn't occur. One to three months after treatment, your physician will likely again examine a stool sample to ensure the infection is gone. If the infection has become tissue-invasive, your physician may prescribe steroids to help with inflammation. In rare cases, surgery may be necessary, if life-threatening cysts have developed in a tissue-invasive infection.

Prevention

• To prevent tapeworm infection, wash your hands with soap and water before eating or handling food, and after using the toilet. Thoroughly cook meat to temperatures of at least 150 degrees Fahrenheit. Freeze meat for at least 12 hours and fish for at least 24 hours to kill eggs and larvae. Avoid eating raw or undercooked meat and treat pets that may be infected with tapeworms.