Tapeworms, the Forgotten But Common Parasite

When people visualize parasites, they often think of something like a tapeworm. A segmented worm that grows up to 12 feet (4 meters) long in the intestines, the tapeworm lives onnourishment from its hosts.

Tapeworms do not even have their own digestive tracts. They take all their nutrition directly from the animal or human they infect. Each worm has both male and female sex organs, allowing it to reproduce freely and to spread its offspring into fecal matter.

Humans typically acquire tapeworm infection by eating undercooked meat that contains tapeworm eggs. Children, however, are more likely to acquire infection by handling dog or cat feces, or by petting animals with less than clean coats. (Only pets that have the infection, of course, pass it on to their owners.)

Even if you do get tapeworms, you may not have symptoms. The species of tapeworm (Taenia solium) most common in the southwestern US, for instance, often causes only a little queasiness or loss of appetite--unless its cysts escape the intestine and lodge in the brain or central nervous system. Taenia saginata, the tapeworm you might actually see caught in toilet paper (and the one kind of tapeworm American labs can identify easily), can cause bowel obstruction or appendicitis. Taenia saginata is found all over the world (except Australia and New Zealand) but is especially common in Latin America and Africa.

The Diphyllobrothium worms found in Finland, Poland, western Russia, China, and Canada can absorb so much vitamin B-12 they cause pernicious anemia, but only after years of infection. The really dangerous Echinococcus tapeworm, typically acquired by eating undercooked fish caught off the shores of western Alaska, can lodge in the lungs and lead to fatal respiratory conditions, but only after 5 to 10 years of infection.

The fact is, tapeworm infections are much more common than most people--including public health officials--think. The tapeworm Taenia solium causes a condition called cysticercosis, the leading cause of epilepsy among Mexican-Americans.

The problem with getting a tapeworm infection in the United States is that doctors don't look for them and labs, even otherwise top-notch labs, don't recognize them in stool samples. Moreover, a tapeworm medicine that might work in, say, Peru, might not work in the United States because the medication is overused for treating less serious conditions.

How can you know you have tapeworms?

Since tapeworms are easily missed on medical exam, it's important that you see your doctor if you notice small white segments in stool or on toilet paper.

So what can you do if you're concerned about tapeworms?

First of all, if you are a pet owner, don't forget about "worming" dogs and cats. Or if your pets haven't been wormed, pet them, but always wash your hands afterwards. You can recognized tapeworms in pets as "grains of rice" that seem to have originated in bowel movement.

Pets get tapeworms from infected fleas, and you can, too. Controlling fleas protects both you and your pet.

Don't eat undercooked fish straight from the ocean. Sushi is OK in developed countries. In the US, fish used in sushi is frozen for 24 hours to kill the tapeworm larvae, which any well-trained sushi chef will recognize in fish.

Tapeworms are rare in the food supply, but they have been noted in beef from cattle fed in feedlots, goats raised in pens, and farmed salmon. They also occur in camel, horse, and hare. Parasite-prone raccoons get tapeworms and many other parasites; eating rare coon meat is begging for an infection. If you eat these foods (and chances are you don't eat all of them), don't eat them raw or rare. Travelers to continental Europe will find horse dishes on many menus, so beware.

It's also important not to eat fruit or cereals that have weevils in them. The weevils can host larvae of the species Hymenolepsis diminuta, another very common form of the parasite throughout the world.

What can you do if you have tapeworms? Follow your doctor's recommendations, and together with your physician consider a parasite flush.

You may also be interested in:

The Pinworm Flush
Parasite-Free Home Drinking Water
Repairing the Nutritional Damage Left by Pinworms
Travel and Trichinosis