Tapeworms are parasitic flatworms that live in the intestines of some animals and humans. They are not usually life threatening, but they can cause some uncomfortable symptoms and health complications if left untreated. Tapeworm infections are fairly rare in developed countries like the United States, but they may be more common in places with poor sanitation and hygiene.
What are tapeworms?
There are several different types of tapeworms that can infect humans:
- Beef tapeworm – Taenia saginata
- Pork tapeworm – Taenia solium
- Fish tapeworm – Diphyllobothrium latum
- Dwarf tapeworm – Hymenolepis nana
Tapeworms have long, flat, segmented bodies. They anchor themselves to the wall of the small intestine using hook-like suckers or teeth. As the tapeworm grows, new segments called proglottids are formed at the head and mature segments are released from the end of the body.
Tapeworms do not have a digestive system themselves – they absorb nutrients directly through their skin. Each proglottid contains male and female reproductive organs and acts like a self-contained living unit. Mature proglottids break off and are passed in the feces, allowing the tapeworm to reproduce.
How do humans get tapeworms?
People get tapeworms by ingesting tapeworm eggs or larvae. There are a few ways this can happen:
- Eating raw or undercooked meat that contains tapeworm larvae.
- Drinking water contaminated with tapeworm eggs.
- Eating vegetables or fruits contaminated with human or animal feces containing eggs.
- Accidentally swallowing a flea infected with tapeworm larvae.
Once the tapeworm eggs or larvae are ingested, they hatch in the small intestine and grow into adult tapeworms that can live for years and grow up to 30 feet long.
What are the symptoms of a tapeworm infection?
Many tapeworm infections cause no symptoms at all. When symptoms do occur, they may include:
- Abdominal pain
- Weight loss
- Loss of appetite
- Itching around the anus
Some people may also notice tapeworm segments passed in their stool. The segments may seem to move on their own for a short time, but they are unable to survive outside of the intestine.
Are tapeworms life threatening?
In most cases, tapeworm infections are not life threatening. However, there are some risks and complications to be aware of:
- Nutritional deficiencies – Tapeworms can rob the body of nutrients, leading to vitamin and mineral deficiencies over time.
- Intestinal blockages – Massive infestations of tapeworms could potentially lead to an intestinal obstruction.
- Cysticercosis – This occurs when tapeworm larvae form cysts in body tissues like the brain, eyes, or muscles. Cysticercosis is a serious condition that can be fatal if left untreated.
The most dangerous type of tapeworm is the pork tapeworm, Taenia solium. This is because the larvae can migrate out of the intestine and form cysts throughout the body. Neurocysticercosis, where cysts form in the brain, is the most severe complication.
Who is most at risk?
Some groups have an increased risk of contracting tapeworms:
- People traveling or living in developing regions with poor sanitation and hygiene.
- Those eating raw or undercooked pork, beef or fish.
- People with compromised immune systems such as HIV/AIDS.
- Those living in institutionalized settings like prisons or psychiatric facilities.
- Impoverished communities lacking adequate healthcare and education.
How are tapeworms diagnosed?
If a tapeworm infection is suspected, a doctor can order several tests to confirm the diagnosis:
- Physical exam – The doctor will feel the abdomen for signs of swelling or tenderness.
- Stool sample – Microscopic examination of a stool sample may reveal tapeworm eggs or segments.
- Blood tests – May show antibodies against tapeworms or signs of vitamin/mineral deficiencies.
- Endoscopy – A tiny camera on a flexible tube can be used to view the upper digestive tract and look for worms.
- Imaging tests – MRIs or CT scans can identify cysts in organs if neurocysticercosis is suspected.
How are tapeworm infections treated?
Several deworming medications are highly effective at killing adult tapeworms and larvae. Common options include:
- Praziquantel – Cures >90% of infections with 1-2 doses.
- Albendazole – Also used to treat neurocysticercosis.
- Nitazoxanide – Used for some types like dwarf tapeworm.
- Niclosamide – Alternative therapy not used as widely today.
Any family members or close contacts may also be treated to prevent spread. People with neurocysticercosis will require specialized treatment and monitoring.
How can tapeworms be prevented?
There are several ways to lower the risk of contracting tapeworms:
- Avoid eating raw or undercooked meat, fish, or produce.
- Only drink clean water, especially when traveling.
- Properly wash hands before cooking and eating.
- Freeze meat for several days at subzero temps to kill parasites.
- Cook meat to safe internal temperatures to kill larvae.
- Prevent flea infestations in pets with monthly preventatives.
Public health efforts like improving sanitation infrastructure and education are also critical for prevention in high-risk regions.
Tapeworm infections are fairly uncommon in the United States and rarely life threatening. However, they can still lead to uncomfortable or alarming symptoms and certain complications. Groups at high risk, especially those eating raw meat or traveling overseas, should take precautions to avoid infection.
With a combination of hygienic food handling, thorough cooking, deworming of pets, and proper diagnosis and treatment, most tapeworm infections can readily be cured or avoided altogether.