Tapeworm infection

DEFINITION

Tapeworm infection is caused by ingesting food or water contaminated with tapeworm eggs or larvae. If you ingest certain tapeworm eggs, they can migrate outside your intestines and form larval cysts in body tissues and organs (invasive infection). If you ingest tapeworm larvae, however, they develop into adult tapeworms in your intestines (intestinal infection).

An adult tapeworm consists of a head, neck and chain of segments called proglottids. When you have an intestinal tapeworm infection, the tapeworm head adheres to the intestinal wall, and the proglottids grow and produce eggs. Adult tapeworms can live for up to 30 years in a host. Intestinal tapeworm infections are usually mild, but invasive larval infections can cause serious complications.

CAUSES

A tapeworm infection starts after ingestion of tapeworm eggs or larvae.

Ingestion of eggs. If you eat food or drink water contaminated with feces from a person or animal with tapeworm, you ingest microscopic tapeworm eggs. For example, a pig infected with tapeworm will pass tapeworm eggs in its feces, which gets into the soil. If this same soil comes in contact with a food or water source, it becomes contaminated. You can then be infected when you eat or drink something from the contaminated source. Once inside your intestines, the eggs develop into larvae. At this stage, the larvae become mobile. If they migrate out of your intestines, they form cysts in other tissues, such as your lungs, central nervous system or liver.

Ingestion of larvae cysts in meat or muscle tissue. When an animal has a tapeworm infection, it has tapeworm larvae in its muscle tissue. If you eat raw or undercooked meat from an infected animal, you ingest the larvae, which then develop into adult tapeworms in your intestines. Adult tapeworms can measure more than 50 feet (15.2 meters) long and can survive as long as 30 years in a host. Some tapeworms attach themselves to the walls of the intestines, where they cause irritation or mild inflammation, while others may pass through to your stool and exit your body.

SYMPTOMS

Many people with intestinal tapeworm infection have no symptoms. If you do feel the effects, your symptoms will depend on the type of tapeworm you have and its location. Invasive tapeworm infection symptoms vary depending on where the larvae have migrated.

Intestinal infection

Signs and symptoms of intestinal infection include:

• Nausea
• Weakness
• Loss of appetite
• Abdominal pain
• Diarrhea
• Weight loss and inadequate absorption of nutrients from food
• Invasive infection
• If tapeworm larvae have migrated out of your intestines and formed cysts in other tissues, they can eventually cause organ and tissue damage, resulting in:
• Fever
• Cystic masses or lumps
• Allergic reactions to the larvae
• Bacterial infections
• Neurological signs and symptoms, including seizures

When to see a doctor

If you experience any of the signs or symptoms of tapeworm infection, seek medical attention.