Amebas are protozoa, and protozoa are a type of parasite. Protozoa make up a diverse group of microscopic, one-celled organisms. Some protozoa need a human or animal host to live. Others do not and are called free-living amebas. Even though free-living amebas are parasites, they live in soil or water and do not need a human or animal host.
Free-living amebas are further categorized as extraintestinal protozoa (see also Introduction to Extraintestinal Protozoa). Extraintestinal protozoa are so-called because they cause infections only in areas outside of the intestines such as the blood, liver, lungs, brain, skin, and the tissues beneath the skin. These infections cause various symptoms and complications.
Free-living amebas rarely cause infections in people, but when they do, the eyes, brain, and skin are the organs most commonly affected.
There are 3 main infections that can be caused by free-living amebas:
(See also Overview of Parasitic Infections.)
