Tapeworm

Tapeworm Basics

Tapeworms are parasites. As you probably remember from biology class, parasites are organisms that live in, or on, other organisms (called "hosts"). Parasites take their nutrients from the host, sometimes depriving the host of nutrition.

Tapeworms get into the body when someone eats or drinks something that's infected with a worm or its eggs. Once inside the body, the tapeworm head attaches to the inner wall of the intestines. The tapeworm feeds off the food that the host is digesting. It uses this nutrition to grow.

Tapeworms are made up of segments, and they get longer by growing new segments. Each segment can reproduce by making thousands of eggs. Since tapeworms can have more than a thousand segments, that's a lot of opportunity to spread. They can grow to more than 33 feet (10 meters) and live as long as 25 years.

New segments grow at the head of the tapeworm, pushing older segments to the end of the line, where they break off. These segments, along with the eggs they contain, pass out of the digestive tract in the host's feces (poop). If the infected feces aren't disposed of in a sanitary way — like down a flush toilet — they can get into the soil or water.

Tapeworm segments can live for months in the environment, waiting for a host to come along. Animals like cows or pigs that eat grass or nose around in the soil can pick up tapeworm segments or eggs. When the tapeworm reaches the animal's intestine, the attach-and-grow cycle begins again.

Causes

Most of the time, people get tapeworm infections from eating food that's contaminated and not prepared properly:

• Tapeworms can spread when someone eats or drinks food or water that's contaminated with infected feces. This is one reason why tapeworm infections are rare in places that have good sanitation, like the United States. Flush toilets, sewer systems, and water treatment plants help keep feces out of the water and food supply.
• People can pass tapeworm eggs on to others when they don't wash their hands after using the bathroom. Tapeworm eggs in feces can easily spread into food or onto surfaces like doorknobs. If you ever need another reason to get your kids to wash their hands, this might do it!
• Kids can get tapeworms from eating meat or fish that hasn't been cooked enough to kill the tapeworm or its eggs.

Symptoms

Most kids who have a tapeworm infection don't feel anything. It can take months or years to notice any symptoms. Some of the things a child might complain of are:

• mild nausea
• diarrhea
• abdominal pain
• loss of appetite and weight loss

Kids with a tapeworm infection may feel a piece of the worm coming out through the anus. If your child has an infection, you may see a tapeworm segment in his or her feces.

There are different types of tapeworms. One (fish tapeworm) can cause anemia because it absorbs vitamin B12, which helps make red blood cells. This can lead kids to feel tired, short of breath, or have other symptoms of anemia.

The eggs of another type of tapeworm (pork tapeworm) can hatch into larvae in the intestine. These larvae go through the intestinal wall and enter the bloodstream. From there they can travel to different parts of the body (such as muscles, eyes, or the brain), where they form cysts. This disease is known as cysticercosis. It is rare in the United States, but common in many developing countries.

With cysticercosis, kids might develop:

• lumps under the skin
• seizures, if the cysts are in the brain
• vision problems, if the cysts are in the eyes
• an abnormal heartbeat, if cysts are in the heart
• weakness or trouble walking, if cysts are in the spine

Eating contaminated pork can lead to a tapeworm infection in the intestines, but it won't turn into cysticercosis. To develop cysticercosis, someone would have to swallow the eggs of the pork tapeworm, and these eggs aren't found in the meat itself. They are found in feces and around the anus.

Cysticercosis occurs as a result of eating food that has been contaminated with feces. It can be any kind of food — all it takes is for that food to come into contact with feces.

When to Call a Doctor

Call a doctor if you see worms in your child's feces or if he or she has abdominal pain or other symptoms that might suggest a tapeworm infection. You'll also want to call a doctor if your child shows signs of infection after traveling to a part of the world that doesn't have good sanitation.

Call a doctor right away if your child has masses or lumps under the skin and develops a fever, headache, or any of the other symptoms of cysticercosis. If your child has seizures or trouble moving, walking, or talking, go to the emergency room right away.

Diagnosis and Treatment

To diagnose a tapeworm infection, doctors usually examine a stool sample for tapeworm segments. Doctors may need to get a couple of samples because tapeworms don't always show up in every sample.

Doctors can easily cure a tapeworm infection with prescription anti-parasite drugs. Often, just one dose is enough.

Tapeworm infection isn't usually serious and most kids have no complications. But in a few rare cases, large tapeworms can block up a child's intestines, appendix, bile duct, or pancreatic duct. This can lead to things like appendicitis or inflamed gall bladder — not pleasant, but they can be treated.

Cysticercosis is a much more serious condition. In some cases, anti-parasite drugs can help shrink cysts and keep them from causing problems. Doctors also may prescribe anti-inflammatory drugs for cysticercosis infections. If a child has seizures, doctors may prescribe anti-epilepsy medications.

If a child gets hydrocephalus because of cysticercosis, doctors might put in a shunt to drain excess fluid. Surgeons will remove cysts if they pose a threat to the eyes, liver, lungs, heart, or other organs.

Prevention

You can protect your family from tapeworm infections by always following these tips:

• Wash your hands thoroughly and often with soap and hot water, especially after using the bathroom or before touching food. Teach your kids to do the same.
• Thoroughly cook meat until juices run clear and the centers are no longer pink.
• Cook fish until it is solid in color (no longer clear) and flakes when separated with a fork.
• Freeze meat for 24 hours before cooking to kill tapeworm eggs.

Here are some things you should do if you're in a place where tapeworm infections are common:

• Wash and cook all fruits and vegetables with safe water.
• Avoid raw or undercooked meat and fish, raw fruits and vegetables that you aren't able to peel yourself, and any food from street vendors.
• Drink only water boiled for a least a minute, bottled water (carbonated is better than regular), or other beverages in bottles and cans. Wipe the top of cans and bottles before you drink from them. Avoid fountain drinks and ice cubes.

Most tapeworm infections are harmless. But it's always a good idea to take your child to a doctor to get checked out if he or she has symptoms.

Reviewed by: Elana Pearl Ben-Joseph, MD
Date reviewed: December 2011