Key points
- Nonpathogenic intestinal protozoa are single-celled parasites that are commonly found in the intestine.
- They are harmless and do not cause illness.
- There is no need for treatment.
Overview
Nonpathogenic intestinal protozoa are single-celled parasites commonly found in the intestinal tract but never associated with illness. They do not harm the body, even in people with weak immune systems. Symptomatic people who are found to have these protozoa in their stool should be examined for other causes of their symptoms.
Species
The nonpathogenic intestinal protozoa include:
- Chilomastix mesnili
- Endolimax nana
- Entamoeba coli
- Entamoeba dispar
- Entamoeba hartmanni
- Entamoeba polecki
- Iodamoeba buetschlii
Symptoms
These nonpathogenic protozoa do not cause illness. Other possible causes of your symptoms should be considered. To see whether you are infected with a pathogen (a disease-causing agent), your healthcare provider might want to check your stool for bacteria, viruses, or other parasites. Another possibility is that your symptoms are not caused by an infection.
How it spreads
You get nonpathogenic intestinal protozoa by swallowing them. For example, by consuming food or water contaminated with feces. This is called fecal-oral transmission. The presence of these protozoa in your stool simply indicates that you had a fecal exposure sometime in the past.
They are found only in the lumen (cavity) of the intestinal tract. They are not found in the cells that line the intestine, and they do not spread to other parts of the body. They can stay in your intestines for weeks, months, or years.