by Sid Kirchheimer
Tapeworms are large, flat parasitic worms that live in the intestinal tracts of some animals. They are passed to humans who consume foods or water contaminated with tapeworm eggs or larvae.
Six types of tapeworms are known to infect humans, usually identified by their source of infestation: beef, pork, fish, dog, rodent, and dwarf, which is named because it is small.
Tapeworm infection in people usually results from eating undercooked foods from infected animals. Pigs or cattle, for example, become infected when grazing in pastures or drinking contaminated water. People can also become infected by eating contaminated fish that is raw or undercooked.
The parasites mature in the animal’s intestines to pea-shaped larvae. They spread to the animal's blood and muscles. They are then transmitted to people who eat the contaminated food. This method is more common with beef or fish.
Tapeworms can also be passed by hand-to-mouth contact if you touch a contaminated surface and then touch your mouth. This method is more common with pork.
Risk Factors TOP
The following factors increase your chances of developing tapeworm infection:
Tapeworms may be seen in vomit or stool. In some cases, tapeworm infection may not cause any symptoms. If symptoms do occur, they may include:
If you have any of these symptoms, see your doctor.
You will be asked about your symptoms and medical history. A physical exam will be done. You may be able to self-diagnose tapeworm infection by checking your stool for signs of tapeworms.
Your bodily fluids and waste may be tested. This can be done with:
Images may be taken of your bodily structures. This can be done with:
Tapeworm infection is treated with oral medication. The medications work by dissolving or attacking the adult tapeworm. The medications may not target eggs. Proper hygiene is essential to avoid re-infection. Always wash your hands before eating or after going to the bathroom.
Your doctor will check stool samples at one and three months after you've finished taking your medication.
To help reduce your chances of getting a tapeworm infection, take the following steps:
Centers for Disease Control and Prevention
The World Health Organization
Public Health Agency of Canada
Centers for Disease Control and Prevention. Traveler's Health—Yellow Book: taeniasis. Centers for Disease Control and Prevention website. Available at: http://wwwnc.cdc.g.... Updated August 1, 2013. Accessed August 15, 2013.
Beef tapeworm. EBSCO DynaMed website. Available at: https://dynamed.ebscohost.com/about/about-us. Updated January 19, 2011. Accessed August 15, 2013.
Silva CV, Costa-Cruz JM. A glance at Taenia Saginata infection, diagnosis, vaccine, biological control and treatment. Infect Disord Drug Targets. 2010 Oct;10(5):313-321.
5/6/2011 DynaMed's Systematic Literature Surveillance https://dynamed.ebscohost.com/about/about-us: Quet F, Guerchet M, et al. Meta-analysis of the association between cysticercosis and epilepsy in Africa. Epilepsia. 2010 ;51(5):830-837.
Last reviewed August 2013 by Michael Woods, MD
Last Updated: 5/11/2013