Nonpathogenic enteric protozoa
- Peter F Weller, MD, FACP
Peter F Weller, MD, FACP
- Editor-in-Chief — Infectious Diseases
- Section Editor — Tropical Medicine
- William Bosworth Castle Professor of Medicine
- Harvard Medical School
- Professor of Immunology and Infectious Diseases
- Harvard T. H. Chan School of Public Health
- Karin Leder, MBBS, FRACP, PhD, MPH, DTMH
Karin Leder, MBBS, FRACP, PhD, MPH, DTMH
- Section Editor — Travel Medicine
- Head of Infectious Diseases Unit
- Monash University, Australia
Several nonpathogenic protozoa inhabit the intestinal tract and may be identified in stool specimens sent to the clinical laboratory for ova and parasite examination [1,2]. Since these nonpathogenic parasites can be reported by the diagnostic laboratory, it is important to be able to distinguish between organisms that require treatment and organisms that do not.
The classification of nonpathogenic protozoa will be reviewed here. Several other enteric organisms, including Blastocystis hominis and Dientamoeba fragilis, are discussed separately. (See "Blastocystis species" and "Dientamoeba fragilis".)
The nonpathogenic protozoa can be divided into two groups: amebae and flagellates. The nonpathogenic amebae include:
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