Tapeworm infection

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 intestine wall, and the proglottids grow and produce eggs. Adult tapeworms can live for up to 20 years in a host. Intestinal tapeworm infections are usually mild, but invasive larval infections can cause serious complications.


Tapeworm infection:

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 symptoms, including seizures

When to see a doctor
If you experience any of the signs or symptoms of tapeworm infection, seek medical attention.


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 up to 50 feet (15.2 meters) long and can survive as long as 20 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. 

Complications:

Intestinal tapeworm infections usually aren't complicated. The complications that do sometimes develop include:

• Digestive blockage. If tapeworms grow large enough, they can block your appendix, leading to infection (appendicits); your bile ducts, which carry bile from your liver and gallbladder to your intestine; or your pancreatic duct, which carries digestive fluids from your pancreas to your intestine.
  
• Brain and central nervous system impairment. Called neurocysticercosis (noor-o-sis-tih-sur-KOE-sis), this especially dangerous complication of invasive pork tapeworm infection can result in headaches and visual impairment, as well as seizures, meningitis, hydrocephalus or dementia. Death can occur in severe cases of infection.
  
• Organ function disruption. When larvae migrate to the liver, lungs or other organs, they become cysts. Over time, these cysts grow, sometimes large enough to crowd the functioning parts of the organ or reduce its blood supply. Tapeworm cysts sometimes rupture, releasing more larvae, which can move to other organs and form additional cysts. A ruptured or leaking cyst can cause an allergy-like reaction, with itching, hives, swelling and difficulty breathing. Surgery or organ transplantation may be needed in severe cases. 

Treatments and drugs:

Some people with tapeworm infections never need treatment, for the tapeworm exits the body on its own. Others don't realize they have it because they have no symptoms. However, if you're diagnosed with intestinal tapeworm infection, medication will likely be prescribed to get rid of it.

Treatments for intestinal infections
The most common treatment for tapeworm infection involves oral medications that are toxic to the adult tapeworm, including:

• Praziquantel (Biltricide)
• Albendazole (Albenza)
• Nitazoxanide (Alinia)

Which medication your doctor prescribes depends on the species of tapeworm involved and the site of the infection. These drugs target the adult tapeworm, not the eggs, so it's important to avoid reinfecting yourself. Always wash your hands after using the toilet and before eating.

To be certain that your tapeworm infection has cleared, your doctor will probably have your stool samples checked at certain intervals after you've finished taking your medication. Successful treatment — meaning that your stool is free of tapeworm eggs, larvae or proglottids — is most likely if you receive appropriate treatment for the type of tapeworm causing your infection.

Treatments for invasive infections
Treating an invasive infection depends on the location and effects of the infection.

• Anthelmintic drugs. Albendazole (Albenza) can shrink some tapeworm cysts. Your doctor may monitor the cysts periodically using imaging studies such as ultrasound or X-ray to be sure the drug is effective.
  
• Anti-inflammatory therapy. Dying tapeworm cysts can cause swelling or inflammation in tissues or organs, so your doctor may recommend prescription corticosteroid medication, such as prednisone or dexamethasone, to reduce inflammation.
  
• Anti-epileptic therapy. If the disease is causing seizures, anti-epileptic medications can stop them.
  
• Shunt placement. One type of invasive infection can cause too much fluid on the brain, called hydrocephalus. Your doctor may recommend placing a permanent shunt, or tube, in your head to drain the fluid.
  
• Surgery. Whether cysts can be removed surgically depends on their location and symptoms. Cysts that develop in the liver, lungs and eyes are typically removed, since they can eventually threaten organ function. Your doctor might recommend a drainage tube as an alternative to surgery. The tube allows aggressive rinsing (irrigation) of the area with anti-parasitic solutions.