What is Strongyloidiasis?

Strongyloidiasis is a disease caused by a nematode, or a roundworm, in the genus Strongyloides. Though there are over 40 species within this genus that can infect birds, reptiles, amphibians, livestock and other primates, Strongyloides stercoralis is the primary species that accounts for human disease. The larvae are small; the longest reach about 1.5mm in length — the size of a mustard seed or a large grain of sand.

How common is Strongyloidiasis?

Strongyloidiasis is common in tropical and subtropical areas, but cases also occur in temperate areas. The parasite is more frequently found in rural areas, institutional settings, and lower socioeconomic groups. Please discuss with your doctor for further information.


What are the symptoms of Strongyloidiasis?

In around 50 percent of cases, strongyloidiasis causes no symptoms. If symptoms are present, they may include:

  • Upper abdominal burning or pain
  • Diarrhea, or alternating diarrhea and constipation
  • A cough
  • A rash
  • Red hives near the anus
  • Vomiting
  • Weight loss

Rashes may occur immediately after contact with the S. stercoralis roundworm. Gastrointestinal symptoms typically appear two weeks after a person is first infected.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes Strongyloidiasis?

Strongyloidiasis is caused by the parasitic roundworm S. stercoralis. This worm infects mainly humans. Most humans get the infection by coming into contact with contaminated soil.

When the larvae come in contact with skin, they are able to penetrate it and migrate through the body, eventually finding their way to the small intestine where they burrow and lay their eggs. Unlike other soil-transmitted helminths such as hookworm and whipworm whose eggs do not hatch until they are in the environment, the eggs of Strongyloides hatch into larvae in the intestine. Most of these larvae will be excreted in the stool, but some of the larvae may molt and immediately re-infect the host either by burrowing into the intestinal wall, or by penetrating the perianal skin. This characteristic of Strongyloides is termed auto-infection. The significance of auto-infection is that unless treated for Strongyloides, persons may remain infected throughout their lifetime.

In addition to contact with soil and auto-infection, there have been rare cases of person-to-person transmission in:

  • Organ transplantation
  • Institutions for the developmentally disabled
  • Long-term care facilities
  • Daycare centers.

Risk factors

What increases my risk for Strongyloidiasis?

You’re at an increased risk for infection if:

  • You travel to or live in South America, Africa, or other tropical regions
  • You live in or travel to rural areas, areas with unsanitary living conditions, or areas without adequate public health services
  • Your job involves regular contact with soil
  • You don’t practice good personal hygiene
  • You have a weakened immune system, such as can occur from HIV or AIDS

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is Strongyloidiasis diagnosed?

The following tests may be performed to diagnose an infection with S. stercoralis:

  • Duodenal aspiration. During this test, your doctor will take fluid from the duodenum, the first section of your small intestine. They’ll then examine the fluid under a microscope for the presence of S. stercoralis.
  • Sputum culture. Your doctor can use a sputum culture to analyze fluid from your lungs or airways for S. stercoralis.
  • Stool sample for ova and parasites. Your doctor can use a stool sample to check for S. stercoralis larvae in the feces. You may need to repeat the test to get accurate results.
  • Complete blood count (CBC) with differential. A CBC test with differential may help to rule out other causes of symptoms.
  • Blood antigen test. A blood antigen test can help your doctor look for antigens to S. stercoralis. It’s performed when your doctor suspects you have an infection but they can’t find the parasite in a duodenal aspiration or in several stool samples. However, the test results can’t be used to tell the difference between a past and current S. stercoralis infection.

The most common methods of diagnosis are microscopic examinations of duodenal or stool samples.

How is Strongyloidiasis treated?

The goal of treatment is to eliminate the worms. The medicine of choice to treat strongyloidiasis is a single dose of the antiparasitic medication ivermectin (Stromectol). This drug works by killing the worms in your small intestine.

Your doctor may also prescribe two courses of albendazole (Albenza), to be taken 10 days apart. Taking thiabendazole (Tresaderm) twice per day for two or three days is also an effective treatment.

You may need longer or repeated courses of medication if the infection is widespread.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage Strongyloidiasis?

The following lifestyles and home remedies might help you reduce your risk of Strongyloidiasis:

  • Practice good personal hygiene
  • Use sanitary facilities
  • Don’t walk barefoot barefoot when traveling to warm or tropical climates

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: August 26, 2018 | Last Modified: August 26, 2018

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