Posted October 23, 2022 by Anusha ‐ 5 min read
Tapeworms infect animals and humans. They live in your intestines and feed off the nutrients you eat. Symptoms can include nausea, weakness, diarrhea and fatigue, or you may not have symptoms. You may see eggs or worm pieces in your poop. Once you find a tapeworm, it’s easy to get rid of it.
What is a Tapeworm?
A tapeworm is a flat, parasitic worm that lives in the intestines of an animal host.
It commonly infects many different animals, including humans, livestock and domestic cats and dogs (usually meat-eating mammals.)
Like other parasites, the mature tapeworm can only survive inside the host animal, feeding off of the host’s own nutrients.
The head attaches to the inside of your intestines and absorbs nutrients from the food digesting there.
What is a Tapeworm infection?
Tapeworm infection comes in two forms:
Intestinal tapeworms are adult tapeworms that have hatched and matured inside the intestines of a host animal.
The mature tapeworms attach to your intestinal walls and absorb nutrients from the food digesting there.
These tapeworms often cause no noticeable symptoms, and many people don’t realize they’re infected.
However, a severe infection can cause nutritional deficiencies, unexplained weight loss, nausea or diarrhea.
Some tapeworms can live up to 30 years and grow up to 30 feet long.
You might hear your healthcare provider refer to your tapeworm infection as
This term refers to an infection by tapeworms from the genus Taenia.
Taenia solium (pork tapeworm), Taenia saginata (beef tapeworm) and Taenia asiatica (Asian tapeworm also from pork) are all species that target humans as their definitive host.
However, other species also infect human intestines, including Diphyllobothrium latum (fish tapeworm) and Hymenolepis nana (dwarf tapeworm a smaller variety).
Invasive Tapeworm larval infection
An invasive larval infection can happen if tapeworm larvae in your intestines migrate outside of your intestines and enter your bloodstream and other organs.
The larvae adhere to your insides and form cysts there pockets of fluid that grow around the larvae as they grow.
These cysts can cause a variety of complications, depending on where they are.
Cysts in your lungs, liver or heart can grow big enough to disrupt those organs normal functioning.
Cysts that adhere to your spinal cord or brain can cause neurological symptoms, such as seizures.
You can have a larval infection with or without an intestinal tapeworm.
The pork tapeworm Taenia solium causes both intestinal infections and invasive larval infection.
(The larval infection is known as cysticercosis.) Other tapeworm species only infect humans as larvae.
These infections go by different names depending on the species cystic hydatid disease (echinococcosis), alveolar disease, sparganosis and coenurosis but they all manifest in the same way, as cysts.
Some cysts don’t cause any trouble, but some do and you may need someone to remove them.
How do you get a Tapeworm infection?
Tapeworms evolve in three stages: egg, larva and adult worm.
The worm can’t survive outside of a living host, but the eggs and larvae can.
Eggs pass from the original host through their poop into the local soil and water.
There, they contaminate the food and drinking water of other animals.
Animals who consume the eggs including insects and fish can incubate the tapeworm larvae.
Humans become infected by accidentally ingesting the eggs or the larvae.
People in less-developed countries with inadequate sewage treatment are more likely than others to get an infection by contamination from poop.
Human and animal waste that contaminates food and water supplies may include the microscopic tapeworm eggs.
When humans ingest the eggs, they hatch into larvae in their intestines, and at this stage they become mobile.
When the larvae migrate outside of your intestines, they cause an invasive larval infection.
In more developed countries, humans are more likely to get an infection from eating undercooked infected meat.
Infected meat has tapeworm larvae embedded in the muscle tissue, which will survive if cooking or freezing doesn’t kill them.
Large freshwater fish, such as salmon, can get an infection.
When humans eat the infected meat, the larvae transfer to their human intestines, where they mature into intestinal worms.
What are the symptoms of Tapeworm infection in humans?
Intestinal tapeworms usually cause mild gastrointestinal symptoms, if any. They may include:
Loss of appetite.
How is Tapeworm infection diagnosed?
Healthcare providers diagnose intestinal tapeworms by examining your poop in a lab.
The lab can spot the tapeworm eggs and worm segments, if there are any, and they can identify which species of worm you have by certain features.
The same medicine treats all of them, but the species will determine the correct dose.
If you have the pork tapeworm, your healthcare provider will want to test for larva infection (cysticercosis) as well.
To check for an invasive larval infection, your healthcare provider may start with a blood test.
The blood test will show if your body is producing antibodies to the larvae.
If the blood test is positive, or if there is some other reason to suspect a larval infection, your healthcare provider will use an imaging test to locate the cysts.
MRI and CT scans are good for looking inside your tissues.
What is the treatment for an invasive larval infection?
Healthcare providers take a tiered approach to treating tapeworm larval infections:
Watch and wait - If the cysts aren’t causing complications and aren’t in any dangerous locations, your healthcare provider may advise leaving them alone for now. They’ll keep an eye on them.
Manage secondary symptoms - If the cysts are causing complications, especially neurological ones, those symptoms may need treatment first. This might mean anti-seizure medication or therapy to reduce fluid buildup in or around the brain.
Corticosteroids - You can use anti-inflammatory medicine, such as corticosteroids, to treat cysts that are causing inflammation in your tissues.
Anthelmintics - Anthelmintic drugs (drugs that kill parasitic worms) can shrink cysts with living larvae in them. Your healthcare provider may give you anthelmintics along with corticosteroids to help reduce the inflammation that happens when the cysts begin to die.
Drainage - If you have cysts that are causing problems, drainage may be an option for some. Your doctor may be able to reach the cysts with a needle and puncture and drain the fluid through the needle. They finish by rinsing the larvae with antiparasitic medication.
Surgery - Cysts that threaten organ function may need surgical removal.