Dientamoeba fragilis is a parasite that is commonly found in the gastrointestinal tract of humans. It may cause illness in some people. The parasite is most likely transmitted via the faecal-oral route. Good hygiene practices should be used to help prevent infection.

Last updated: 01 November 2015

What is Dientamoeba fragilis?

Dientamoeba fragilis is a parasite that is commonly found in the gastrointestinal tract of humans. It is found in populations around the world and is increasingly recognised as a parasite with the potential to cause illness in humans.

What are the symptoms?

Many people who are infected with Dientamoeba fragilis do not have any symptoms. In those that do show symptoms, these include loose stools, diarrhoea and abdominal pain. Other reported symptoms are weight loss, loss of appetite, nausea and fatigue.

How is it spread?

The way Dientamoeba fragilis is spread is not yet clear. Given that the parasite is found in the gastrointestinal tract, transmission is most likely to occur via the faecal-oral route. This means that infection might occur if you bring something to your mouth that has touched the faeces of a person infected with Dientamoeba fragilis or if you swallow food or water contaminated with the parasite.

Who is at risk?

Dientamoeba fragilis is found in the intestines of many people, some without ever having symptoms. People who travel to regions with poor sanitation are at higher risk of infection.

How is it prevented?

As infections seem to be more common in places with poor sanitation, it is important to practice good hand hygiene, especially after using the toilet and before handling food.

Some general precautionary measures that should be taken are:

  • Wash hands thoroughly using soap for at least 10 seconds and dry them with a clean towel after using the toilet, before preparing food and after handling nappies.
  • Avoid food or water that may be contaminated by sewage
  • Wash and peel all raw vegetables and fruits before eating
  • When travelling in countries where the water supply may be unsafe, avoid drinking unboiled tap water.

How is it diagnosed?

Diagnosis of a Dientamoeba fragilis infection is based on symptoms and on finding the parasite from one or more stool samples.

How is it treated?

There are medications available to treat Dientamoeba fragilis infections. However, these are not always effective in relieving symptoms so it may be necessary for the doctor to look for other possible causes of a patient’s symptoms.

What is the public health response?

Dientamoeba fragilis is not a notifiable condition in New South Wales and there is no public health response required for individual infections.

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