The Amoeba are a large group of organisms that change shape and move through the use of pseudopods or extensions of their cytoplasm. They are microscopic and therefore not visible by the naked eye. Only a few Amoeba are pathogenic or cause clinical disease in humans. Most Amoeba are harmless and have a symbiotic relationship with the host.

The intestinal Amoeba as expected are detected in the feces. They are detected as either the motile trophozoite form or the dormant cyst form. The dormant cyst form develops in response to environmental pressure in order for the organism to survive in the external environment and continue its cycle.

The following are the main intestinal Amoeba that are looked for in examinations. Entamoeba histolytica being the most significant of the Amoeba in terms of pathogenicity. The other Amoeba are important for two reasons. Identification rules out Entamoeba histolytica and it also indicates the ingestion of contaminated water or food that may be the source of another pathogen.

Click on any of the following for a brief description of each intestinal Amoeba.

• Entamoeba histolytica
• Entamoeba coli
• Entamoeba hartmanni
• Entamoeba polecki
• Endolimax nana
• Iodamoeba butschlii

The following are the most common extra intestinal Amoeba causing disease in humans. It is important to note that these Amoeba are extremely pathogenic commonly leading to morbidity and mortality in infected humans. Especially if there is a delay in detection / treatment.

Click on any of the following for a brief description of each extra intestinal Amoeba.

• Naegleria fowleri
• Acanthamoeba species
• Balamuthia mandrillaris