Diphyllobothrium latum - Complications of a tapeworm infection

The beef tapeworm lives only in your intestine and infection with it is easily treated. However, infection with other tapeworms or tapeworm larvae can lead to complications, which are outlined below.

In rare cases, infection with tapeworm larvae can be life threatening.

Cysticercosis

The larvae (cysticerci) of the pork tapeworm can cause cysticercosis. This is when cysts (tiny sacs) enclosing the larvae settle outside your intestines in other tissues and organs, such as your lungs, liver, eye or brain.

The cysts grow very slowly and cause inflammation (swelling). If they settle in an organ, such as the liver, they affect its normal function.

The cysts can become infected with bacteria (a secondary infection) and can burst. If a cyst bursts, its contents can cause a severe and sometimes life-threatening allergic reaction called anaphylaxis.

Neurocysticercosis is a particularly dangerous complication of infection with pork tapeworm larvae. It affects the brain and central nervous system, causing headaches and affecting sight. It can also cause meningitis, epilepsy or dementia. If the infection is severe, it can be fatal.

Hydatid disease

Hydatid disease (echinococcosis) is caused by larvae of the dog tapeworm. The organs most commonly affected are the liver and lungs, although the larvae can also settle in the bones or brain.

Over many years, the larvae form hydatid cysts, which are filled with watery liquid containing many tapeworm larvae (called hydatid sand). The cysts are usually 1-7cm (1-3 inches) in size, although they can be as big as 30cm (12 inches).

Infection can begin during childhood, but symptoms may not show for many years, unless the main organs are affected.

Blocked digestive system

Very rarely, tapeworms may grow large enough to block parts of your digestive system, including the:

• intestine
• pancreatic ducts
• bile ducts
• appendix

This could lead to infections, such as appendicitis, as well as other complications.