Strongyloidiasis

Strongyloidiasis is an infection with the parasitic worm Strongyloides. It lives in contaminated soil and infects you through your skin. Some infections become chronic, lasting for years. Strongyloidiasis can cause life-threatening illness if you have a weakened immune system. Antiparasitic medications treat strongyloidiasis.

Overview

What is strongyloidiasis?

Strongyloidiasis is an infection with Strongyloides, a parasitic worm. It’s sometimes called Strongy. The worm gets into your body through your skin and makes its way to your lungs and intestines, where it matures and reproduces.

Some infections can last for years. It can cause skin or digestive symptoms that come and go (intermittent) or no symptoms at all. If you have a weakened immune system, strongyloidiasis can be life-threatening.

Where is Strongyloides found?

Strongyloides worms exist all over the world, but they’re more commonly found in warmer climates (tropical and subtropical areas) and rural or economically disadvantaged areas. In the U.S., Strongyloides has been found in rural areas of the South and Southeast, especially Appalachia. But most cases in the U.S. are in people who were infected in other areas of the world.

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Who does strongyloidiasis affect?

Anyone can get strongyloidiasis. But some activities and conditions put you at higher risk, including:

  • A weakened immune system, especially from corticosteroid therapy or an infection with human T-cell lymphotropic virus-1 (HTLV-1). This also puts you at risk for a life-threatening illness.
  • Walking with bare feet in soil.
  • Work that puts you in contact with soil that could be contaminated, like farming or coal mining.
  • Living in an area with inadequate sanitation.

How do you know if you have Strongyloides?

Symptoms of strongyloidiasis are similar to many other illnesses, and some people have no noticeable symptoms at all. The only way to know if you’re infected is to have a provider test you.

How common is strongyloidiasis?

Experts estimate that 30 to 100 million people worldwide are infected with Strongyloides. But since many people don’t have symptoms, it can be hard to know how many people have it.

Where is Strongyloides found in the body?

Strongyloides worms move through your skin and bloodstream and can reproduce in your lungs or intestines.

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How does strongyloidiasis affect my body?

Young Strongyloides worms get into your body through your skin. You don’t need to have a cut or break in your skin for this to happen. The worms can cause an itchy rash while moving through your skin.

Once inside your body, they move into your bloodstream to reach your lungs. There, they grow into adults. They sometimes lay eggs and reproduce in your lungs, causing a cough or scratchy throat.

You can cough up and swallow the adult worms into your stomach and GI (gastrointestinal) tract. They lay eggs in your intestines, which hatch and grow into more worms. This can cause digestive symptoms, such as nausea, diarrhea or stomach pain.

The worms can leave your body in your poop, which spreads the infection. They can also reinfect you from inside your body or through your skin (autoinfection).

What is autoinfection?

Strongyloides can complete its life cycle (lay eggs that hatch into more infectious worms) entirely inside your body. This means they can reinfect you repeatedly without you coming in contact with new worms from the soil (autoinfection). This repeating cycle can cause chronic strongyloidiasis, which can last for years without treatment.

What is Strongyloides hyperinfection?

Most people have strong enough immune systems to keep a Strongyloides infection from causing serious illness. But if you have a weakened immune system, the worms can invade other parts of your body (disseminated strongyloidiasis), cause severe organ inflammation or bring bacteria into your bloodstream. This can lead to life-threatening conditions, like sepsis and pneumonia.

You’re at higher risk for hyperinfection if you:

Symptoms and Causes

What are the symptoms of strongyloidiasis?

The most common symptoms of strongyloidiasis include:

  • Raised, red, itchy rash (larva currens), often between your butt cheeks, on your thighs or on your wrists.
  • Nausea.
  • Diarrhea.
  • Upper abdominal pain that can be similar to heartburn or an ulcer.
  • Bloating.
  • Cough or scratchy throat (less common).

Most people don’t have symptoms, or their symptoms come and go.

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What causes strongyloidiasis?

Several types of Strongyloides, a parasitic worm that lives in soil (dirt), cause strongyloidiasis. They’re more common in warm climates and areas where poop is more likely to contaminate the soil.

They get into your body through your skin, even if you don’t have any cuts or breaks in it. Then they move to your blood, lungs and intestines.

What causes hyperinfection with Strongyloides?

If you have a weakened immune system, your body can’t keep Strongyloides from causing serious damage. Life-threatening strongyloidiasis is called hyperinfection. You can get a hyperinfection even if your immune system becomes weakened when you already have strongyloidiasis (even if you had no symptoms before).

Is strongyloidiasis contagious?

Strongyloidiasis isn’t usually contagious. Most people get it from contact with contaminated soil. Rarely, people have gotten infected from other people or from transplanted organs.

Diagnosis and Tests

How is strongyloidiasis diagnosed?

To diagnose strongyloidiasis, your provider will need to test one or more body fluids to look for Strongyloides. They may look for rashes on your body, including on your wrists or thighs or between your butt cheeks.

What tests will be done to diagnose strongyloidiasis?

Your provider may take samples of different body fluids to look for signs of a Strongyloides infection, including:

  • Stool (poop).
  • Sputum (mucus coughed up from your lungs).
  • Blood.

Management and Treatment

How is strongyloidiasis treated?

Antiparasitic medications treat strongyloidiasis. Ivermectin, sometimes given with albendazole, is the most effective treatment. You usually have to take medications for two to 14 days or longer. If you’re on immunosuppressive therapy, your provider may temporarily reduce the amount of immunosuppressants you take.

Even if you don’t have symptoms, it’s very important to treat a Strongyloides infection to reduce your risk of hyperinfection.

Prevention

How can I prevent strongyloidiasis?

Some ways you can reduce your risk for strongyloidiasis include:

  • Wear protective clothing when you’re around soil in areas where Strongyloides lives. This includes shoes and gloves.
  • Be especially cautious in areas with inadequate sanitation. This increases the risk of Strongyloides contaminating the soil.
  • If you’re going to have a procedure or start medication that will weaken your immune system, ask your provider about testing for infections. If they diagnose you with strongyloidiasis, you can treat it while you still have a strong immune system. This can prevent hyperinfection.

Outlook / Prognosis

What can I expect if I have strongyloidiasis?

If you have a weakened immune system, you must get treated immediately for a Strongyloides infection. You may need to be hospitalized or treated multiple times to get rid of the infection.

If you have a healthy immune system, antiparasitic medications can often successfully get rid of the infection. You’ll need to follow up with your provider after treatment to make sure all of the worms are gone.

Can strongyloidiasis be cured?

Yes, antiparasitic treatments can cure strongyloidiasis, especially in people with healthy immune systems. Hyperinfections have life-threatening complications that are harder to treat.

Living With

How do I take care of myself?

Talk to your provider about screening for infections if you have a weakened immune system. Ask them about preventing illness and what to do if you get sick.

When should I see a healthcare provider?

See a healthcare provider if you:

  • Have symptoms of strongyloidiasis.
  • Have a weakened immune system and have concerns about Strongyloides infections.
  • Are traveling to an area where Strongyloides is common, especially if you have a weakened immune system. Talk to your provider about preventing infection.
  • Will undergo treatment or a procedure that’ll weaken your immune system. A provider may test you for infections before starting treatment.

When should I go to the ER?

Go to the ER if you have any symptoms of serious illnesses, including:

  • High fever (103 degrees Fahrenheit /39.4 degrees Celsius).
  • Confusion or other mental changes.
  • Low blood pressure.
  • Trouble breathing or shortness of breath while sitting still.
  • New or worsening chest pain.
  • Not peeing or peeing very little.

What questions should I ask my doctor?

  • How can I prevent infections like Strongyloides?
  • Should I be screened for strongyloidiasis?
  • Am I at high risk for serious illness from strongyloidiasis?
  • How do I take my medications?
  • How soon will I feel better?
  • When should I follow up with you?
  • When should I go to the ER?

A note from Cleveland Clinic

Most people with strongyloidiasis don’t get seriously ill. But it can cause life-threatening illness if you have a weakened immune system. If you’re going to have an organ transplant, start corticosteroid therapy, or have a weakened immune system from any other cause, ask your provider if you should be screened for strongyloidiasis. Early treatment is the best way to prevent severe illness.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 02/02/2023.

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