Amebiasis -  Fact Sheet


What is amebiasis?
Amebiasis is an intestinal illness caused by a microscopic parasite called Entamoeba histolytica.

Who gets amebiasis?
Anyone can get amebiasis, but it is recognized more often in people arriving from tropical or subtropical areas, individuals in institutions for the developmentally disabled and homosexual males.

Where are the parasites that cause amebiasis found?
Infected people are the only sources of the parasite. The parasite is excreted in fecal material of infected individuals.

How is this disease spread?
Although the disease can be transmitted through food or water contaminated by feces from infected individuals, in the United States it is usually transmitted from person-to-person by hand to mouth transfer of feces. Transmission may also occur sexually by oral-anal contact.

What are the symptoms of amebiasis?
People exposed to this parasite may experience mild or severe symptoms or no symptoms at all. Fortunately, most exposed people do not become seriously ill. The mild form of amebiasis includes nausea, loose stools, weight loss, abdominal tenderness and occasional fever. Rarely, the parasite will invade the body beyond the intestines and cause a more serious infection, such as a liver abscess.

How soon after exposure do symptoms appear?
The symptoms may appear from a few days to a few months after exposure but usually within two to four weeks.

For how long can an infected person carry this parasite?
Some people with amebiasis may carry the parasite for weeks to years, often without symptoms.

How is it diagnosed?
Examination of stools under a microscope is the most common way for a doctor to diagnose amebiasis. Sometimes several stool samples must be obtained to detect the parasite in the stool.

What is the treatment for amebiasis?
Specific antibiotics can be prescribed by a doctor to treat amebiasis.

Should an infected person be excluded from work or school?
Generally, it is not necessary to exclude an infected person from work or school. Casual contact at work or school is unlikely to transmit the disease. Special precautions may be needed by food handlers or children enrolled in day care settings. Consult your local health department for advice in such instances.

What preventative measures should be followed?
The most important precautions are careful hand washing after each toilet visit and proper disposal of sewage. Persons should avoid sexual practices that may permit fecal-oral transmission.

This fact sheet is for informational purposes only. It should not be used for self-diagnosis or as a substitute for consultation with a health care provider. If you think that you may have this infection, or have questions about the disease described above, consult a health care provider.



For additional information on this disease, visit the Centers for Disease Control and Prevention website.

To contact the Epidemiology and Emerging Infections Program, please call 860-509-7994.