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 larvae.
Six types of tapeworms are known to infect humans, usually identified by their source of infestation: beef, pork, fish, dog, rodent, and dwarf (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 surface contaminated with tapeworm eggs and then touch your mouth. This method is more common with pork.
The following factors may increase your chance of a 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:
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 of your brain may be taken if there is concern that the larva of the pork tapeworm have migrated there. 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.
Surgery may occasionally be needed for pork tapeworm larvae in the brain
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 1 and 3 months after you've finished taking your medication.
To help reduce your chance of a tapeworm infection:
Centers for Disease Control and Prevention
The World Health Organization
Public Health Agency of Canada
Beef tapeworm. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T114440/Beef-tapeworm. Updated January 19, 2011. Accessed December 7, 2016.
Centers for Disease Control and Prevention. Traveler's Health—Yellow Book: Taeniasis. Centers for Disease Control and Prevention website. Available at: http://wwwnc.cdc.gov/travel/yellowbook/2014/chapter-3-infectious-diseases-related-to-travel/taeniasis. Updated July 10, 2015. Accessed February 23, 2016.
Silva CV, Costa-Cruz JM. A glance at Taenia Saginata infection, diagnosis, vaccine, biological control and treatment. Infect Disord Drug Targets. 2010;10(5):313-321.
5/6/2011 DynaMed Plus Systematic Literature Surveillance http://www.dynamed.com/topics/dmp~AN~T114440/Beef-tapeworm: 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 March 2017 by EBSCO Medical Review Board Michael Woods, MD, FAAP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.