Tapeworm Infection: Symptoms and Treatments

Tapeworm eggs in the stool of a person infected with tapeworm can be transmitted to others. Tapeworm infection occurs by swallowing tapeworm eggs, which can get into food from improper food handling.

The worms live and grow in the digestive tract and can spread to other parts of the body. Tapeworm infections are uncommon in the United States and tend to occur more often in parts of the developing world due to contaminated and undercooked meat or fish. When an infection does occur, it is relatively easy to treat.

This article looks at the symptoms and causes of tapeworm infection and what is needed to diagnose, treat, and prevent taeniasis.

Types of Infection

Tapeworms are a type of parasitic flatworm. They have a head, a neck, and a body consisting of many segments called proglottids. The proglottids may contain eggs.

Tapeworm infection can be classified as either intestinal infection or invasive infection. Intestinal infection that occurs with any of the three Taenia species results in a condition known as taeniasis.

The pork tapeworm can cause cysticercosis, an invasive infection that has spread to the brain, muscle, and other tissues. The parasitic larvae escape the intestinal tract to form cysts in other parts of the body. Infection by larval cysts in the nervous system—neurocysticercosis—is a serious condition.

Tapeworm Infection Symptoms

In most cases, infection with a tapeworm causes few or no symptoms. In fact, many people with taeniasis do not even realize that they've been infected.

If there are signs and symptoms of taeniasis, they may include:

• Abdominal pain
• Diarrhea
• Fatigue
• Hunger
• Lack of appetite
• Nausea
• Passing tapeworm segments in the stool
• Weight loss

Neurocysticercosis can cause headaches, seizures, and confusion.

An untreated infection can also lead to vitamin B12 deficiency which, in turn, can cause anemia. This condition can occur when your body lacks enough healthy red blood cells to carry sufficient oxygen to the tissues in your body.

Signs and symptoms of anemia can include:

• Chills
• Dizziness and fainting
• Headaches
• Jaundice (yellowing of the skin)
• Paleness
• Tiredness
• Weakness
• Shortness of breath
• Irregular heartbeat

Is It Possible to Feel a Tapeworm?

You won't be able to feel a tapeworm while it's in your system. However, you may be able to feel one as it passes through your anus during a regular bowel movement.

Complications

With certain types of tapeworm, such as those that infect pork, the larvae can move out of the digestive system and form fluid-filled larval cysts in other body parts (called cysticercosis). This may result in masses or lumps under the skin or in body tissues or organs.

If cysts develop in the central nervous system or the brain, there can be neurological symptoms referred to as neurocysticercosis. In severe cases, this condition can be life-threatening.

Some tapeworm species can get rather big. Pork, beef, and fish tapeworms can grow between 15 feet and 30 feet long. Not all achieve these lengths, however. The aptly named dwarf tapeworm doesn't grow longer than 2 inches.

When to See a Healthcare Provider

Many cases of taeniasis are asymptomatic (without symptoms). If you experience any of the signs or symptoms of tapeworm infection after traveling to an endemic area, seek medical attention.

This is especially true if you experience any of the rare signs and symptoms of cysticercosis, including:

• Severe headache with a stiff neck
• Abnormally rapid heartbeat
• Rapid, shallow breathing
• Sensitivity to light
• Vomiting
• Confusion
• Sudden bulging of veins in the scalp and forehead
• Downward deviation of the eyes
• An allergy-like reaction, with itching, hives, swelling, and difficulty breathing (caused by the bursting of larval cysts)

Causes

Several species of tapeworm can infect humans including:

• Pork tapeworm (Taenia solium)
• Beef tapeworm (Taenia saginata)
• Asian tapeworm (Taenia asiatica)
• Fish tapeworm (Diphyllobothrium latum)
• Dwarf tapeworm (Hymenolepis nana)
• Dog tapeworms (Echinococcus granulosus and Echinococcus multilocularis), sometimes

Infections are more common in the developing world in areas, where sanitation facilities are lacking and people may be in close contact with animals. Tapeworm infections in humans occur most often as a result of eating undercooked or raw beef, pork, or fish from an animal that was infected.

Another cause of infection is poor hygiene after coming in contact with tapeworms or tapeworm eggs. Poor hygiene can be improved with proper handwashing, for example. This is why it is important to wash your hands with soap and water after using the toilet, after changing diapers, and before preparing food.

Undercooked Meat, Pork, or Fish

Eating undercooked or raw meat, pork, or fish is the most common way that people are infected with a tapeworm. If the animal had tapeworms, the person eating the meat can also become infected.

The life cycle of a tapeworm begins with eggs. Tapeworm eggs can live outside of a host and in the environment (such as in water or on plants) for days or even months. Animals may become infected after eating plants or feed or drinking water that contains tapeworm eggs.

Once inside an animal host, the eggs hatch and mature into young tapeworms. The worms are mobile and can migrate out of the intestine and into muscle tissue.

If not frozen or cooked properly to kill the worms, the animal's meat contains living tapeworms. They then can be passed on to a human who eats the meat.

Pork Tapeworm Eggs

A less common way of becoming infected with tapeworms is through contact with eggs from the pork tapeworm (T. solium). The eggs are shed in the stool of an animal or a human who is infected.

The eggs can remain viable in the environment, including in water. This is why it's important to ensure that the water you drink is germ-free.

The eggs can also be spread if an infected person doesn’t wash their hands well after going to the bathroom and then handles food that is eaten by others.

Pork tapeworm eggs can also live on surfaces. It's possible to become infected through the use of objects such as dishes or silverware that have eggs on them.

International Travel

While infection with tapeworms does occur in the United States, it is more common in the developing world. Travel to areas where infections with tapeworms are common is a risk factor for people in the United States diagnosed with taeniasis or cysticercosis.

Cysticercosis mainly affects subsistence farming communities in developing countries of Africa, Asia, and Latin America.

Diphyllobothrium infection is prevalent in northern Europe, Russia, Canada, Africa, Japan, Taiwan, Manchuria, Siberia, Papua New Guinea, Australia, and South America.

Diagnosis

Diagnosis of infection in the digestive system includes testing the stool for tapeworms and/or looking at the anus area for eggs. Some people may notice tapeworms on or around their anus. A healthcare practitioner should see them during a physical exam.

In some cases, tapeworm segments may be visible in the stool. If this occurs, it is important to take a stool sample to a physician or a lab to get it tested.

A stool test can determine which type of tapeworm is present. It might be necessary to collect and test stool from several different bowel movements over a few days to make the diagnosis.

Blood tests for vitamin B12 levels and/or anemia may be done if there is an infection with the fish tapeworm. A blood test that looks for specific antibodies may be used to help diagnose cysticercosis.

Imaging tests such as a computed tomography (CT) scan or magnetic resonance imaging (MRI) may also be done if there are complications from an infection with pork tapeworm eggs that have migrated to other parts of the body.

Tapeworm Infection Treatment

Unfortunately, tapeworms don't just go away on their own. If a tapeworm infection isn't treated, the parasite is likely to stay put. Depending on the type of tapeworm, you may never know it's there.

In cases of intestinal tapeworm infection, treatment requires a medication that will immobilize the worms. Once the worms are unable to hang onto the lining of the intestine, they will be passed out of the body during a bowel movement.

Biltricide (praziquantel) is an antiparasitic drug commonly used to treat tapeworm infections. For infection with the dwarf tapeworm (H. nana), a medication called Alinia (nitazoxanide) may be appropriate.

For complications from infection with pork tapeworm eggs that have formed cysts, treatment will depend on the location of the cysts. It may be necessary to use medication or another treatment to manage the infection and associated complications in other areas of the body.

Prevention

Since the majority of tapeworm infections are the result of international travel, it is important to adhere to infection control practices when traveling to areas where tapeworms are endemic (widespread).

This includes parts of Africa, Asia, and Latin America where there is subsistence farming (meaning nearly all of the crops or livestock raised are used to maintain the farmer and the farmer's family).

In order to prevent tapeworm infection while traveling abroad:

• Cook all meat and fish well done to a temperature of 145 degrees F.
• Alternatively, fully freeze for at least 24 hours to a temperature of -31 degrees F.
• Eat only cooked or canned fruits or vegetables.
• If you do eat any fresh fruits or vegetables, be sure they are thoroughly washed and peeled by you before eating.
• Boil water for three minutes before drinking, or drink only bottled water.
• Wash your hands thoroughly with soap and water.
• Teach children not to put their hands in their mouths.

Summary

Tapeworms are parasitic worms that can infect the digestive tract. Pork tapeworms can even move out of the gut and form cysts in other parts of the body, including the muscles and brain.

The most common way to get tapeworms is by eating infected beef, pork, or fish. Washing your hands is important, especially in areas where infection is common, because it can help prevent transmitting tapeworm eggs in stool to other people.

Diagnosis may involve an exam, stool tests, blood tests, and imaging. The infection is manageable and usually treated with medications that cause the worms to be passed out of the body. It's important to get the infection treated to prevent serious complications.