Cysticercosis

What is cysticercosis?

Cysticercosis (pronounced “cys-ti-cer-CO-sis”) is an illness you get when you’re infected with the eggs of the parasite Taenia solium (T. solium), a pork tapeworm. Sacs of fluid (cysts) that T. solium forms in your body cause symptoms to develop.

You get cysticercosis from eating food or drinking water contaminated with T. solium eggs or from not washing your hands after touching poop (feces) that has T. solium eggs in it. The eggs hatch in your gut (intestines) and the young (larval) tapeworms form cysts in other parts of your body, like your brain and your eyes.

What’s the difference between cysticercosis and taeniasis?

You get cysticercosis when you accidentally eat (ingest) T. solium eggs, which form cysts in your body. You get taeniasis when you eat undercooked pork infected with larval T. solium, which grows into an adult tapeworm in your gut.

Who does cysticercosis affect?

Cysticercosis is most common in people who live in or travel to rural areas in Central and South America, sub-Saharan Africa, Asia and Eastern Europe. People who’ve moved to the U.S. from those regions have a higher risk of being infected with T. solium. You’re also at higher risk if you live with someone who has taeniasis (T. solium tapeworm infection).

How common is cysticercosis?

About 2.7 million people worldwide have cysticercosis. In regions where pig cysticercosis is common (Central and South America, sub-Saharan Africa, Asia and Eastern Europe), about 10%-20% of the human population has symptoms of cysticercosis. Though cysticercosis is uncommon in North America, about 2% of emergency room visits for seizures in the U.S. are from cysticercosis.

What are the symptoms of cysticercosis?

The symptoms of cysticercosis depend on where cysts form. You can have cysts almost anywhere, including your brain, eyes, heart, muscle tissue or liver.

The most common symptoms are from cysts in your nervous system, called neurocysticercosis.

Neurocysticercosis (cysticercosis of the brain and spinal cord) symptoms

• Seizures.
• Headaches.
• Nausea, vomiting and confusion (cysticercal encephalitis).
• Stiff neck.

Any cysts outside of your brain and spinal cord (nervous system) are called extraneural cysticercosis. Extraneural cysticercosis usually doesn’t cause symptoms except in certain locations. Cysts under your skin (subcutaneous cysticercosis) or ophthalmic cysticercosis (cysticercosis of the eye) sometimes cause symptoms, including:

• Lumps under your skin.
• Eye pain.
• Double vision (diplopia).
• Eye inflammation (uveitis or retinitis).
• Limited eye movement.
• Bulging eyes (proptosis).
• Vision loss.

What causes cysticercosis?

An infection with eggs of the parasite T. solium causes cysticercosis. You can get cysticercosis by eating or drinking something that has T. solium eggs on it (like unwashed fruits and vegetables or untreated water) or by touching your mouth after touching something with T. solium eggs in it (like poop or something contaminated with poop).

The eggs hatch in your intestines, and young T. solium worms move out into the tissues of your body and form sacs (cysts). These cysts usually don’t cause symptoms unless there are a lot of them in one place. You can have them for weeks to years without knowing it. Your immune system responds when the cysts die, causing symptoms.

How does cysticercosis affect the brain?

When their eggs hatch in your intestine, T. solium larvae can move to your brain and form cysts. These cysts can sometimes stay there for a long time without causing symptoms.

When the cysts start to die, your immune system recognizes them as invaders and causes inflammation to attack them. If there are lots of cysts, they can put pressure on your brain (mass effect) even before they start to die. Inflammation from your immune system or pressure from mass effect can lead to life-threatening brain swelling and cause seizures, headaches and other neurological issues.

When cysts die, they can leave behind hard patches (calcifications) in your brain. Calcified cysticercosis nodules are surrounded by fluid (edema) and can lead to seizures.

How does cysticercosis spread?

Cysticercosis spreads through the poop of someone infected with the adult tapeworm T. solium. T. solium lays its eggs in human intestines and then the eggs leave your body in your poop. You get cysticercosis from ingesting something that’s contaminated by poop carrying these eggs.

Poop can get into soil, water, plant material and the food we eat. You can accidentally ingest T. solium eggs after coming in contact with something that’s contaminated, such as:

• Drinking water that hasn’t been boiled or treated.
• Eating unwashed fruits or vegetables.
• Touching your mouth or eating after using the bathroom or touching poop.

You don’t get cysticercosis from eating undercooked pork.

Is cysticercosis contagious?

No, cysticercosis isn’t contagious from person to person. You have to ingest T. solium eggs to get infected.

How is cysticercosis diagnosed?

To diagnose cysticercosis, a healthcare provider will perform a physical exam and ask you about your symptoms. They might ask about your travel history. The provider may order imaging (CT scan or MRI), blood tests, a lumbar puncture, biopsy or eye exam.

How do you test for cysticercosis?

To diagnose cysticercosis, your healthcare provider may order some or all of these tests:

• Imaging: Your healthcare provider will probably have a CT scan or MRI performed if you have symptoms of cysticercosis in your nervous system. This is where you lie down in a machine that takes images of your brain. Your provider can see if the images show T. solium cysts.
• Blood tests: Blood tests are sometimes performed to look for cysticercosis. Your provider uses a needle to take blood from your arm, then they send your blood sample to a lab. The lab might look for antibodies to T. solium (cysticercosis serology test) or for specific parts of the parasite (antigens).
• Lumbar puncture: If your provider thinks you have cysticercosis of the brain or spinal cord, they may test your cerebrospinal fluid (CSF) with a lumbar puncture. In this procedure, your provider uses a needle to draw CSF from your lower back. Similar to a blood test, the lab might look for T. solium antibodies or antigens.
• Biopsy: Your provider may take a small amount of tissue and send it to a lab to look for signs of T. solium. This is usually done if you have visible skin lumps.
• Eye exam: Your provider may want to take a close look at your eyes to see if you have any cysts that could affect your vision.

How do you treat cysticercosis?

The treatment for cysticercosis varies. You might not require treatment, or your healthcare provider may prescribe a combination of medications. You may require surgery. Your provider will tailor a treatment plan to your specific case.

What medications and procedures are used to treat cysticercosis?

Your healthcare provider may prescribe some of these medications or procedures to treat cysticercosis:

• Corticosteroids (prednisolone, dexamethasone) to reduce inflammation.
• Antiepileptic/anticonvulsant medications (phenytoin, carbamazepine) to prevent seizures.
• Antiparasitic medications (albendazole, praziquantel) are sometimes used to treat the infection.
• Surgery to remove cysts or to put in a tube (shunt) to redirect the fluid in your brain.

How can I prevent cysticercosis?

Safe food and water preparation and hand washing are the most important things you can do to help prevent cysticercosis.

• Wash your hands with soap and water frequently, especially after using the bathroom, after changing diapers, before eating and before preparing food.
• Wash fruits and vegetables thoroughly or peel before eating.
• Wash cutting boards, counters, dishes and utensils with soapy water after use.
• Don’t drink untreated water.
• If you’re traveling to a place where you don’t know if the water is treated, drink bottled or boiled water only. Boil water for one minute before allowing to cool and then drinking.
• Filter drinking water with an “absolute 1 micron or less” filter (found at camping supply stores), then dissolve iodine tablets into filtered water before drinking.

What can I expect if I have cysticercosis?

As cysticercosis often has little or no symptoms, it can be hard to say what the typical course of the illness is. Your healthcare provider will determine a treatment plan that’s unique to you. In some cases, this may mean not treating cysticercosis right away.

Is cysticercosis fatal?

Cysticercosis isn’t often fatal. Most symptoms are caused by immune system inflammation as the cysts die, rather than the disease itself. If you have few cysts and minimal symptoms, your outlook is very good.

How do I take care of myself with cysticercosis?

If you’ve been diagnosed with cysticercosis, keep an eye on your symptoms. Whether you’ve been prescribed treatment or not, call your healthcare provider if your symptoms don’t improve or get worse.

When should I see my healthcare provider?

If you have symptoms of cysticercosis, especially seizures, confusion or unexplained nausea or vomiting, contact a healthcare provider right away or go to the nearest ER.

A note from Cleveland Clinic

Cysticercosis is an illness you get when you’re infected with the eggs of the parasite Taenia solium. While you might not have heard of it where you live, cysticercosis can cause serious illness. If you live in or are traveling to an area where cysticercosis is common, following a few simple hygiene habits can help keep you safe.