Strongyloidiasis (pronounced strong-a-loyd-eye-a-sis) is an infection caused by a type of worm called Strongyloides stercoralis.

It establishes itself in the gut.

How it is spread

The infective form of the worm (the larvae) lives in soil that has been contaminated by an infected person’s faeces.

This means it’s usually confined to environments where sanitation is poor.

If a person comes in contact with this soil, the larvae may burrow through the person’s skin.

They will then make their way to their lungs, and then their gut where they will become adult worms.

These worms then produce eggs that hatch and develop into infective larvae.

The larvae can:

  • pass through in their faeces or
  • burrow into their skin near the anus and continue to re-infect the individual (auto-infection).

Transmission from person-to-person can occur but this is uncommon.


The time from infection until a person might develop symptoms is variable.

Many people infected don’t have any symptoms.

Some people may:

  • get a migrating itchy rash when the larvae are burrowing under the skin
  • have chest symptoms like wheezing and coughing when the larvae reach the lungs
  • experience gut symptoms such as abdominal pain, diarrhoea and bloating - this is common in children with initial infection
  • have nausea, vomiting, weight loss, weakness or constipation.

In chronic infections, skin and chest symptoms can persist.

If an infected person experiences no symptoms and their immune system becomes weakened, they may become unwell years later.

Immunocompromised people

If a person’s immune system is weakened enough to allow many larvae to move throughout the body, a life-threatening form of the disease can occur.

It is called ‘disseminated Strongyloidiasis’, which is a rare complication that is seen in immunocompromised people.

This includes those on chemotherapy or high dose steroids for more than 2 weeks.

It has also been associated with HTLV-I infection which is present in central Australian Aboriginal people.

Infectious period

If an infected person is experiencing auto-infection, they can pass Strongyloidiasis on to others via the soil cycle.

Once treated, they are no longer infectious. But they can become re-infected if they're exposed to contaminated soil again.

Who is at risk

In Australia, Strongyloidiasis is common in:

  • those living in or travelling to Aboriginal communities
  • World War II veterans
  • immigrants from South-East Asia, Africa and South American tropical and subtropical regions.

If people in these groups are about to start medication that affects their immune system, they should get tested for Strongyloidiasis before starting treatment.


Strongyloidiasis is treated with specific anti-worm medication, depending on the infected person's age.

Some infected people may require medication but many people clear Strongyloidiasis without it.


There is no vaccine available for the prevention of Strongyloides.

To prevent Strongyloidiasis, good hygiene and sanitation is the best way.

In settings where it is prevalent, you should:

  • wear footwear in areas known or likely to have contaminated soil
  • wear gloves when handling soil known or likely to have been contaminated
  • wash your hands after going to the toilet, changing soiled linen and every nappy change
  • ensure there are sewage systems in place to treat and dispose of faeces in a safe manner.


For more information, contact the Centre for Disease Control.

Last updated: 23 August 2022

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