How Do People Get Tapeworm? Complete Guide

Tapeworm infections are caused by eating the larvae of these parasitic flatworms, which live in the muscle tissue of undercooked meat or contaminated food. People get tapeworms primarily by consuming raw or undercooked beef, pork, or freshwater fish that contains the larval cysts, or by ingesting food or water contaminated with tapeworm eggs. Once swallowed, the larvae attach to the intestinal wall and grow into adult worms, which can live in the digestive tract for years if not treated.

How Do People Get Tapeworm From Meat?

The most common way people get tapeworms is by eating raw or undercooked meat. The tapeworm life cycle depends on an animal host. Cattle, pigs, and freshwater fish become infected when they graze on or ingest contaminated feed or water containing tapeworm eggs.

When a person eats meat from an infected animal that has not been cooked thoroughly, the larval cysts survive. Once in the human intestine, the larva attaches to the intestinal wall and develops into an adult tapeworm. This is called an intestinal tapeworm infection.

Different tapeworm species come from different animals:

• Beef tapeworm (Taenia saginata) comes from undercooked beef.
• Pork tapeworm (Taenia solium) comes from undercooked pork.
• Fish tapeworm (Diphyllobothrium latum) comes from raw or undercooked freshwater fish.

Freezing meat does not reliably kill tapeworm larvae. Cooking meat to a safe internal temperature is the only dependable way to kill the cysts. The U.S. Department of Agriculture recommends cooking whole cuts of beef, pork, and fish to an internal temperature of 145°F, and ground meats to 160°F.

Can You Get a Tapeworm From Contaminated Food or Water?

Yes. Some tapeworm infections do not come from meat at all. They come from swallowing microscopic tapeworm eggs that are shed in human feces.

This happens when an infected person does not wash their hands properly after using the bathroom, then handles food that someone else eats. Contaminated water can also carry the eggs. Fruits and vegetables washed in contaminated water or fertilized with untreated sewage can carry tapeworm eggs as well.

When a person swallows tapeworm eggs, the eggs hatch in the intestine. The larvae then burrow through the intestinal wall and travel through the bloodstream to other parts of the body. This is called a larval tapeworm infection or cysticercosis. It is a different and more serious condition than an adult tapeworm living in the intestine.

This route of transmission is why good hand hygiene and safe sanitation matter. A person with an intestinal pork tapeworm can infect themselves or others with the eggs without realizing it.

What Are the Symptoms of a Tapeworm Infection?

Many people with an intestinal tapeworm have no symptoms at all. The worm can live quietly in the intestine for months or years without causing noticeable problems.

When symptoms do appear, they are often mild and nonspecific. Common symptoms include:

• Nausea
• Weakness
• Diarrhea
• Abdominal pain
• Loss of appetite
• Weight loss

Some people notice segments of the tapeworm in their stool. These segments look like small white or pale yellow grains of rice. They may move slightly when freshly passed.

A vitamin B12 deficiency can develop in some people with a fish tapeworm infection. The worm absorbs B12 from the host’s intestine, which can lead to anemia over time.

Symptoms of a larval infection depend on where the larvae travel in the body. If larvae reach the brain, a condition called neurocysticercosis, symptoms can include seizures, headaches, and confusion. This is a medical emergency that requires immediate treatment.

How Is a Tapeworm Infection Diagnosed?

Diagnosis usually starts with a stool sample. A laboratory technician examines the sample under a microscope to look for tapeworm eggs or segments. Because eggs are not passed in every stool sample, multiple samples over several days may be needed.

A blood test can detect antibodies against tapeworms. This test is more useful for detecting larval infections than intestinal infections. Imaging tests such as CT scans or MRI scans are used when a larval infection is suspected in the brain or other organs.

If you think you may have a tapeworm infection, see a healthcare provider. Do not try to treat it yourself with herbal remedies or over-the-counter products. No reliable home treatment exists.

How Is a Tapeworm Infection Treated?

Intestinal tapeworm infections are treated with prescription antiparasitic medications. The most commonly used drugs are praziquantel and niclosamide. These medications cause the adult worm to detach from the intestinal wall and pass out of the body in the stool.

Treatment is usually a single dose or a short course of medication. The medication is highly effective for intestinal infections. Follow-up stool samples are often checked a few weeks after treatment to confirm the worm is gone.

Larval infections are more complex to treat. They may require a combination of antiparasitic drugs, anti-inflammatory medications to reduce swelling, and sometimes surgery. Treatment for neurocysticercosis should always be managed by a specialist because of the risk of complications.

How Can You Prevent a Tapeworm Infection?

Prevention is straightforward and highly effective. The most important step is cooking meat and fish to safe internal temperatures. Use a food thermometer to check.

Other key prevention steps include:

• Wash hands with soap and water after using the bathroom and before handling food.
• Wash and peel raw fruits and vegetables before eating them.
• Drink safe water. In areas with poor sanitation, use bottled or boiled water.
• Freeze meat for several days at very low temperatures if you plan to eat it raw or undercooked. Note that home freezers may not reach low enough temperatures to reliably kill all larvae.
• Practice good hygiene when traveling to areas where tapeworm infections are more common.

Pet owners should know that tapeworms in dogs and cats come from swallowing infected fleas. These are a different species of tapeworm and are not directly transmitted to humans through contact with the pet. However, good flea control and hygiene remain important.

Who Is at Higher Risk for a Tapeworm Infection?

Tapeworm infections are more common in certain regions of the world, particularly in areas with poor sanitation and where livestock are raised without strict inspection practices. These areas include parts of Latin America, sub-Saharan Africa, Southeast Asia, and Eastern Europe.

In the United States, tapeworm infections are relatively rare. The people most at risk are those who:

• Travel to areas where tapeworms are common
• Eat raw or undercooked meat or freshwater fish regularly
• Live in or visit areas with poor sanitation
• Have close contact with someone who has an intestinal tapeworm infection

People who frequently eat raw freshwater fish, such as in sushi or ceviche, should be aware of the risk. Saltwater fish are generally not associated with the fish tapeworm.

Are Tapeworm Infections Serious?

An intestinal tapeworm infection in a healthy adult is usually not serious. It causes mild symptoms or none at all, and it is easily treated with medication.

The serious form of the disease is cysticercosis, caused by ingesting pork tapeworm eggs. When larvae travel to the brain, the condition can be life-threatening. This is why it is important to treat intestinal infections promptly and to practice strict hand hygiene if you have one.

Complications from intestinal tapeworms are uncommon but possible. A large worm can occasionally cause a blockage in the intestine. The fish tapeworm can cause vitamin B12 deficiency and anemia. These complications are treatable but require medical attention.