If you have not dewormed for the past five years, see what will happen to you for the next two years.

Tapeworm are flat, segmented worms that live in the intestines of some animals. Animals can become infected with these parasites when grazing in pastures or drinking contaminated water.

Eating undercooked meat from infected animals is the main cause of tapeworm infection in people. Although tapeworms in humans usually cause few symptoms and are easily treated, they can sometimes cause serious, life-threatening problems. That's why it's important to recognize the symptoms and know how to protect yourself and your family.

Six types of tapeworms are known to infect people. They are usually identified by the animals they come from -- for example, Taenia saginata from beef, Taenia solium from pork, and Diphyllobothrium latum from fish.

Tapeworms have a three-stage lifecycle: egg, an immature stage called a larva, and an adult stage at which the worm can produce more eggs. Because larvae can get into the muscles of their hosts, infection can occur when you eat raw or undercooked meat from an infected animal.

It is also possible to contract pork tapeworms from foods prepared by an infected person. Because tapeworm eggs are passed with bowel movements, a person who doesn't wash hands well after wiping and then prepares food can contaminate the food.

Tapeworm Symptoms

Sometimes tapeworms cause symptoms such as:

Nausea
Weakness
Diarrhea
Abdominal pain
Hunger or loss of appetite
Fatigue
Weight loss
Vitamin and mineral deficiencies
However, often tapeworms don't cause symptoms. The only sign of tapeworm infection may be segments of the worms, possibly moving, in a bowel movement.

In rare cases, tapeworms can lead to serious complications, including blocking the intestine. If pork tapeworm larvae move out of the intestine, they can migrate to other parts of the body and cause damage to the liver, eyes, heart, and brain. These infections can be life-threatening.

Treatment for Tapeworms

If you suspect you have tapeworms, see your doctor. Diagnosing a tapeworm infection may require a stool sample to identify the type of worm.

If worms are not detected in the stool, your doctor may order a blood test to check for antibodies produced to fight tapeworm infection. For serious cases, your doctor may use imaging tests such as computed tomography (CT) or magnetic resonance imaging (MRI) to check for damage outside the digestive tract.

The type and length of treatment may depend on the type of tapeworm you have. Tapeworms are usually treated with a medicine taken by mouth. The most commonly used medicine for tapeworms is praziquantel (Biltricide).

These medications kill the tapeworms. The dead tapeworms then dissolve or pass from your body with bowel movements. If worms are large, you may have cramping when they pass. Your doctor will recheck stool samples at one and three months after you finish treatment. When tapeworms are confined to the intestines, appropriate treatment gets rid of them in more than 95% of people.

More serious complications of tapeworm infection are also treated with medications