Tapeworm Infection

A tapeworm is a parasitic worm that lives in the intestines of a person or animal (host). It has a flat shape, like a soft measuring tape. It looks pale yellow or white. There are three distinct parts:

• Head: This attaches to the host.
• Neck: New body segments generate from here.
• Lower body: This is the longest part of a tapeworm. It grows in parts or segments, which look like a chain of tiny grains of rice. The body segments may produce their own eggs.

Tapeworms usually infect meat-eating animals, like humans, livestock, cats and dogs. If a tapeworm is from the genus Taenia, healthcare providers may call the infection “taeniasis.” These may include:

• Taenia saginata (beef tapeworm)
• Taenia solium (pork tapeworm)
• Taenia asiatica (Asian tapeworm, also from pork)

Other tapeworm species can also infect humans. These include Dibothriocephalus latus (fish tapeworm) and Hymenolepsis nana (dwarf tapeworm, which is a smaller type).

What is a tapeworm infection?

A tapeworm infection is when a tapeworm enters a host’s body. This usually happens through contaminated food or water. The tapeworm’s head attaches to the intestinal lining. It absorbs nutrients from foods and drinks. As it grows, it lays eggs. The eggs pass out of your body in your poop. This is how tapeworm eggs infect new hosts.

Tapeworm infections occur around the world. But they’re more common in areas where people commonly eat raw meat and fish or don’t have access to water and sanitation. Tapeworms can also spread through the fecal-oral route. For example, you can get a tapeworm by eating food or drinking water that comes into contact with infected poop. You can also spread it if you don’t wash your hands after using the bathroom, and someone touches an infected surface and then their mouth.

Healthcare providers can treat many tapeworm infections with medications.

What are the types of infection?

Tapeworm infections come in two forms:

• Intestinal tapeworms
• Invasive tapeworm larval infection

Intestinal tapeworms

These are adult (mature) tapeworms that hatch and mature inside the intestines of a host. Some tapeworms can live for decades in your intestines and grow to over 80 feet (25 meters) long.

Invasive tapeworm larval infection

This type of infection can happen if immature tapeworms (larvae) enter your bloodstream from your intestines and go to other organs. They cling to your insides and form fluid-filled pockets (cysts). The cysts may not cause any problems. But if they get big enough, they can impact how well the affected organs work.

You can have a larval infection with or without an intestinal tapeworm.

Symptoms of a tapeworm infection

Not everyone has symptoms. But if you do, intestinal tapeworm symptoms may include:

• Hunger
• Loss of appetite
• Feeling like you might throw up (nausea)
• Feeling very tired (fatigue)
• Stomach cramps
• Diarrhea
• Wiggly white or pale yellow segments in your poop

Larval infections may cause symptoms like:

• Bumps you can see or feel under your skin
• Pain or swelling around your infected organ
• Coughing or chest pain if larvae attach to your lungs
• Headaches, seizures and confusion if larvae attach to your brain or spinal cord

They may also prevent affected organs from working as well as they should.

Causes

Most people get a tapeworm infection by:

• Eating contaminated meat or fish
• Touching poop that has tapeworm eggs in it

Mature tapeworms can’t survive outside of a host. But tapeworm eggs and larvae can. When infected animals poop, eggs and larvae can contaminate food and drinking water. Animals, fish and even insects that ingest the eggs or larvae then become new hosts. Humans can get a tapeworm from eating raw or undercooked meat. They can also get it from fruits and vegetables that have come in contact with contaminated poop or water.

Complications

Complications depend on a few factors. These include what kind of tapeworm you have, whether it’s intestinal or invasive, and where cysts are in your body. But without treatment, a tapeworm infection can cause problems like:

• Blockages in your digestive system, including your intestines, appendix, bile ducts and pancreatic duct
• Vitamin deficiency anemia
• Allergic reactions to tapeworm larvae, including itching, hives and trouble breathing

Pork tapeworms also cause cysticercosis.

How doctors diagnose a tapeworm infection

A healthcare provider will:

• Review your health history
• Ask about any symptoms
• Conduct a physical exam

If they suspect you have a tapeworm, they may recommend a poop (stool) test. They’ll examine a sample of your poop in a lab to look for tapeworm eggs or segments. They’ll also determine which type you have.

If you have a pork tapeworm, your provider will check for a larval infection. They may recommend a larval antibody blood test. They may also suggest an MRI or CT scan to look for cysts in in your body.

How is a tapeworm infection treated?

To treat an intestinal tapeworm, your healthcare provider will prescribe antiparasitic medications, like:

• Praziquantel
• Albendazole
• Nitazoxanide
• Niclosamide

Providers most commonly recommend praziquantel. It forces the tapeworm to let go of your intestines. If the tapeworm’s neck doesn’t dislodge and pass from your body, the worm can create new body segments.

After treatment, your provider may recommend more stool tests over the next few months. These help ensure the tapeworm is gone.

If you have an invasive larval infection, your provider may recommend:

• A “watch and wait” approach, which means not treating cysts if they aren’t causing problems and aren’t in a dangerous area, but keeping an eye on them
• Managing any secondary symptoms that may occur, like anti-seizure medications or therapy to reduce fluid buildup in or around your brain
• Corticosteroids to treat cysts that cause inflammation in your tissues
• Antiparasitic medications to shrink cysts with living larvae in them
• Fine-needle aspiration to drain cyst fluid and rinse larvae with antiparasitic medication
• Surgery to remove any cysts that affect how well an organ works

Recovery time

With a proper diagnosis and treatment, an intestinal tapeworm will die and pass from your body within a few days. But if you have a tapeworm and never discover it, it’ll eventually die naturally and pass from your body. But this may take years or even decades.

If you have an invasive larval infection and it doesn’t cause symptoms, your provider may recommend that you leave any cysts alone. The larvae will eventually die after a period of years.

When should I see my healthcare provider?

It can be challenging to realize you have a tapeworm because they don’t always cause symptoms. And when they do, the symptoms may be similar to other common conditions. Call a provider if you notice visible tapeworm segments in your poop. This is usually the first sign of infection. Let them know about any possible exposures to tapeworms. Examples include foreign travel or if you eat raw or undercooked meat.

What can I expect if I have a tapeworm infection?

With a proper diagnosis and treatment, the prognosis is usually good. But if you have an invasive larval infection and cysts develop in major organs, like the heart or brain, your outlook can be poor. You can develop serious complications. Surgical treatments can also be challenging. Your provider will give you a better idea of what to expect according to your unique situation.

Can a tapeworm infection be prevented?

The best ways to prevent a tapeworm infection are to:

• Wash your hands with soap and clean water before eating and after using the restroom, changing diapers and touching animals.
• Boil untreated water for at least one minute before drinking it or using it to cook.
• Cook meats to an internal temperature of at least 160 degrees Fahrenheit (71 degrees Celsius) and fish to an internal temperature of at least 145 F (63 C) before eating.
• Freeze fish for at least seven days at -4 F (-20 C) before eating.