Amebiasis (amebic dysentery)

Reviewed: March 2023

What is amebiasis?

Amebiasis is an intestinal (bowel) illness caused by a microscopic (tiny) parasite called Entamoeba histolytica, which is spread through human feces (poop). Often there are no symptoms, but, sometimes it causes diarrhea (loose stool/poop), nausea (a feeling of sickness in the stomach), and weight loss.

Who gets amebiasis?

Anyone can get this disease, but in the United States, amebiasis is most common in:

  • People who have traveled to tropical places with poor sanitary conditions
  • Immigrants or travelers from tropical countries with poor sanitary conditions
  • People who live in institutions with poor sanitary conditions
  • Men who have sex with men

How is amebiasis spread?

The parasite lives only in humans and is passed in the feces (poop) of an infected person. A person gets amebiasis by putting anything in their mouth that has touched infected feces or by eating or drinking food or water contaminated with the parasite. It can also be spread sexually by oral-anal contact. Some people with amebiasis may carry the parasite for weeks to years, often without symptoms, continually passing it in their feces.

What are the symptoms of amebiasis and when do they appear?

The majority of people who are infected with this parasite will experience no symptoms. Those who do become sick may experience mild or severe symptoms. The mild form of amebiasis includes nausea (a feeling of sickness in the stomach), diarrhea (loose stool/poop), weight loss, stomach tenderness, and occasional fever. Rarely, the parasite will spread the body beyond the intestines and cause a more serious infection, such as a liver abscess (a collection of pus). The symptoms may develop a few days to a few months after exposure but usually within two to four weeks.

How is it diagnosed?

Examination of stools (poop) under a microscope is the most common way for a doctor to diagnose amebiasis. Sometimes, several stool samples must be collected because the number of amoeba being passed in the stool, which varies from day to day, may be too low to detect from any single sample.

What is the treatment for amebiasis?

Several antibiotics are available to treat amebiasis. Treatment must be prescribed by a physician.

What can be done to prevent the spread of amebiasis?

Careful handwashing with soap and water after using the toilet or handling soiled diapers and proper disposal of sewage is the most important way to prevent amebiasis. People with amebiasis should avoid sexual contact until the infection is treated and has cleared. When traveling to a country with poor sanitary conditions, it is important to drink water from sources you know to be safe such as sealed bottled water, boiled tap water, and carbonated (bubbly) water from sealed cans. It is also important to be careful about the food you eat: avoid eating food from street vendors, fresh fruit or vegetables that you did not peel yourself, and raw (unpasteurized) dairy products.

Should an infected person be excluded from work or school?

Although people with diarrhea (loose stool/poop) due to amebiasis should not attend school or go to work, it is not necessary to exclude infected persons when they feel better and stools are normal. Casual contact at work or school is unlikely to spread the disease. Children enrolled in daycare settings may need to take special precautions. Food handlers may not work until recovery from infection and when appropriate treatment has been completed. Consult your local health department for advice in such instances.