What is a tapeworm infection?

Tapeworms are a type of parasite. They lay eggs, which then hatch into larvae before maturing into an adult tapeworm.

Humans can become infected by eating or drinking tapeworm eggs or larvae in contaminated meat or water.

If you swallow tapeworm eggs, the eggs hatch into larvae. These larvae break through the wall of the intestines and grow inside cysts in body tissues.

If you swallow tapeworm larvae, they can develop into adult tapeworms in the intestines. They attach to the wall of the intestine and stay there to feed and grow. An adult tapeworm can grow very long and live for many years.

What are the symptoms of tapeworm infection?

Many people with tapeworm infection have no symptoms. If you have symptoms, they will depend on the type of tapeworm and where it is in your body.

Intestinal tapeworm infection can cause:

• abdominal (tummy) pain
• nausea
• diarrhoea or constipation
• loss of appetite or increased appetite
• weight loss
• seeing pieces of worm in your poo

Serious symptoms can include:

• sleep and behavioural problems
• headaches
• seizures
• vision problems

What causes tapeworm infection?

Tapeworm infection happens when you swallow tapeworm larvae or eggs. This can happen through:

• eating undercooked meat, such as beef, pork or fish
• drinking contaminated water
• contact with tapeworm eggs from contaminated dog poo

You are more likely to get tapeworm infection if you:

• live on a farm
• have close contact with dogs or pigs
• practice poor hand hygiene
• drink contaminated water
• eat undercooked meat and fish

When should I see my doctor?

See your doctor if you:

• have symptoms of tapeworm infection
• don't have symptoms but are worried you may have a tapeworm
• think you may have consumed contaminated food

If your child has tapeworm, they may still go to school.

How is tapeworm infection diagnosed?

Your doctor will ask for a stool (poo) sample and a blood test to confirm whether you have tapeworm. They will also check what kind of tapeworm you have.

Hydatid disease is an infection caused by tapeworm larvae. It forms cysts, mostly in the liver and lungs, but can affect other organs. You may need an ultrasound, brain CT or MRI scan to diagnose the cysts.

How is tapeworm infection treated?

Your doctor will prescribe medicine to treat tapeworm infection, usually from the class of medicines called anthelmintics. Sometimes surgery in needed to remove cysts.

After treatment for intestinal tapeworm infection, your doctor should re-check your stool (poo) to make sure the infection is gone. If tapeworms are still present, you may need another round of treatment.

What are the complications of tapeworm infection?

Tapeworm larvae form cysts, mostly in the liver and lungs but they can also affect other organs. In rare but serious situations, tapeworm infections can lead to sepsis if cysts become infected with bacteria.

Some types of tapeworms can also cause anaemia by absorbing vitamin B12 from your body.

Can tapeworm infection be prevented?

Tips to reduce your risk of tapeworm infection:

• Wash your hands after using the toilet and before handling food.
• Follow safe food-handling guidelines.
• Don't eat undercooked pork, beef and fish.
• Control tapeworm infection in your dog with preventive deworming and treat tapeworm infection in your pets.
• Do not let a dog lick your face.

Resources and support

• Victoria Department of Health offers guidelines and advice about infectious diseases, including tapeworm infection.
• DermNet offers information about tapeworm infection.
• SA Health offers information on worms, including symptoms, treatment and prevention.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

Do you prefer to read in languages other than English?

Visit the Royal Children's Hospital to read about the symptoms, diagnosis and treatment of threadworm in community languages.