Tapeworms are flat, ribbon-like worms that can live in your gut if you swallow their eggs or small, newly hatched worms.
Tapeworm infections are rare in the UK, but are fairly common in other parts of the world.
Many don't cause obvious symptoms and can be easily treated. But very occasionally, the worms can spread to other parts of the body and cause serious problems.
Symptoms of a tapeworm infection
Tapeworms usually cause few or no symptoms. You may only find out you have one if you spot a bit of worm in your poo.
Worms in your poo
Bits of tapeworm found in poo are often:
- flat and rectangular
- white or pale yellow
- the size of a grain of rice – but sometimes they're joined together in a long chain
The pieces of worm may move about.
If you see tiny white worms that look like pieces of thread, they're probably threadworms. These are common in the UK, particularly in children.
Tapeworms can also sometimes cause other symptoms, such as:
More serious symptoms can appear if worms get into other parts of the body, such as the brain or liver.
Read more about the complications of tapeworm infections.
When to see your GP
See your GP if:
- you see any worms or bits of worm in your or your child's poo
- you have any worrying symptoms that don't go away, such as tummy pain, diarrhoea, or weight loss
If you see a worm in your poo, it can help to put the poo in a clean container and take it to your GP. They can send it to a laboratory to find out what it is.
If you don't have a sample to bring in, your doctor may give you a container and ask you collect one when you next do a poo. They may also look for eggs or small worms around your bottom.
As tapeworms are rare in the UK, your GP may refer you to a specialist for further tests and treatment if they think you might have one.
Treatment for a tapeworm infection
A tapeworm infection can usually be treated with a single tablet of a prescription medicine called niclosamide or praziquantel. This kills the worm so it passes out in your poo.
In the weeks after taking the tablet, make sure you wash your hands regularly – particularly before eating and after using the toilet. This will stop any eggs getting into your mouth and infecting you again.
A sample of your poo will be checked after a few months to see if the treatment has worked.
Even if you've passed a large piece of worm, this doesn't always mean it's gone completely. It could regrow if some of it's left in your gut.
How you get tapeworms
You can get a tapeworm infection if their eggs or small newly hatched worms (larvae) get in your mouth.
There are several ways this can happen, including:
- eating raw or undercooked beef, pork, or freshwater fish (like salmon or trout) – these can contain live tapeworm larvae if they're not cooked thoroughly
- drinking water or eating food that contains or has been in contact with bits of poo of an infected person or animal
- close contact with someone who has a tapeworm – they may pass out eggs in their poo, which can get on clothing, surfaces, and food
Tapeworms are found throughout the world, including in the UK, but you're more likely to get them in places with poor sanitation and less strict food hygiene standards.
Preventing tapeworm infections
To help reduce your chances of getting a tapeworm:
- don't eat raw or undercooked pork, beef, or freshwater fish
- cook meat and fish thoroughly and all the way through – don't allow raw meat or fish to touch cooked meat or fish
- wash vegetables and fruit before you eat them
- wash your hands with soap and water before handling food, before eating, after using the toilet, and after close contact with animals
- when travelling abroad, only drink water you know is clean – read more advice about food and water safety abroad
Take extra care if you work or live closely with animals or are staying in a part of the world where tapeworm infections are common.
Complications of tapeworm infections
In rare cases, tapeworms can cause serious problems if newly hatched worms get from the gut into other organs, such as the brain or liver.
The worms can form sacs called cysts, which can stop the affected organ working properly.
This can only occur if you swallow the eggs of a type of tapeworm found in pigs, which can happen if tiny bits of poo of someone with this tapeworm get into your mouth. It can't happen from eating pork.
Depending on where they form, the cysts can cause problems such as:
- headaches and fits (seizures)
- yellowing of the skin and eyes (jaundice)
- a cough, shortness of breath, or coughing up blood
- vision problems
- a serious allergic reaction (anaphylaxis) – this can happen if a cyst bursts open
Cysts can be difficult to treat. Treatment may involve a long course of anti-worm medicine and possibly surgery to remove the cysts.
Dog tapeworms (hydatid disease)
In some parts of the world (and rarely in the UK), a type of tapeworm found in dogs can spread to people. This is called hydatid disease.
Infections with these tapeworms can be serious and difficult to treat, but simple precautions like getting your dog dewormed regularly and not feeding them raw meat can help you avoid it.
Read more about hydatid disease.