Cysticercosis is an infection caused by the larvae of the parasite Taenia solium. This infection occurs after a person swallows tapeworm eggs. The larvae get into tissues such as muscle and brain, and form cysts there (these are called cysticerci). When cysts are found in the brain, the condition is called neurocysticercosis.
People get cysticercosis when they swallow T. solium eggs that are passed in the feces of a human with a tapeworm. Tapeworm eggs are spread through food, water, or surfaces contaminated with feces. Humans swallow the eggs when they eat contaminated food or put contaminated fingers in their mouth. Importantly, someone with a tapeworm can infect him-or herself with tapeworm eggs (this is called autoinfection), and can infect others in the family. Eating pork cannot give you cysticercosis.
Humans get the tapeworm infection after eating raw or undercooked pork contaminated with cysts of T. solium. When swallowed the cysts pass through the stomach and attach to the lining of the small intestine. In the small intestine the cysts develop into adult tapeworms over about two months.
Cysticercosis is found worldwide. Infection is found most often in rural areas of developing countries where pigs are allowed to roam freely and eat human feces and where hygiene practices are poor. Cysticercosis is rare in people who live in countries where pigs do not have contact with human feces. People can sometimes get cysticercosis even if they have never traveled outside of the United States.
Signs and symptoms will depend on the location and number of cysts in your body.
- Cysts in the muscles:
- Cysts in the muscles generally do not cause symptoms. However, you may be able to feel lumps under your skin. The lumps sometimes become tender.
- Cysts in the eyes:
- Although rare, cysts may float in the eye and cause blurry or disturbed vision. Infection in the eyes may cause swelling or detachment of the retina.
- Neurocysticercosis (cysts in the brain, spinal cord):
- Symptoms of neurocysticercosis depend upon where and how many cysts are found in the brain. Seizures and headaches are the most common symptoms. However, confusion, lack of attention to people and surroundings, difficulty with balance, excess fluid around the brain (called hydrocephalus) may also occur. The disease can result in death.
Symptoms can occur months to years after infection, usually when the cysts start dying. When cysts die, the brain or other tissue around the cyst may swell. The pressure of the swelling is what usually causes the symptoms of the infection. Sometimes symptoms are caused by the pressure of cyst in a small space.
See your health care provider.
Your health care provider will ask you about your symptoms, where you have traveled, and the kinds of foods you eat. Diagnosis may require blood tests and/or imaging studies. Diagnosis of neurocysticercosis is usually made by MRI or CT brain scans. Blood tests are available to help diagnose an infection, but may not always be accurate. If surgery is necessary to remove a cyst, the diagnosis can be made by the pathologist who looks at the cyst.
Yes. Infections are generally treated with anti-parasitic drugs in combination with anti-inflammatory drugs. Surgery is sometimes necessary to treat cysts in certain locations, when patients are not responsive to drug treatment, or to reduce brain swelling. Not all cases of cysticercosis need treatment. Even if you don’t need treatment to kill the parasite, you may need treatment for the symptoms caused by the infection, such as medication to reduce the number of seizures you have.
No. Someone with cysticercosis cannot spread the disease to other people. However, people with taeniasis (tapeworm infection in the intestine) may spread tapeworm eggs to other people if they do not practice good hygiene (e.g. hand washing after they use the toilet), which may result in cysticercosis if people swallow the eggs.
More on: Taeniasis
Yes. Family members may also need to be tested. Because the tapeworm infection can be difficult to diagnose, your health care provider may ask you to submit several stool specimens over several days or to examine your stools for evidence of a tapeworm.
- Wash your hands with soap and warm water after using the toilet, changing diapers, and before handling food
- Teach children the importance of washing hands to prevent infection
- Wash and peel all raw vegetables and fruits before eating
- Use good food and water safety practices while travelling in developing countries such as:
- Drink only bottled or boiled (1 minute) water or carbonated (bubbly) drinks in cans or bottles
- Filter unsafe water through an “absolute 1 micron or less” filter AND dissolve iodine tablets in the filtered water; “absolute 1 micron” filters can be found in camping and outdoor supply stores
More on: Handwashing
More on: Food and Water Safety