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Amebiasis is an infection caused by a parasite (Entamoeba histolytica).

Amebiasis is an infection caused by a parasite (Entamoeba histolytica). In severe cases, it can cause bloody diarrhea.

The basics

How is Amebiasis spread?

People get amebiasis by eating the germ. This can happen by eating or drinking contaminated food or water, or by having contact with the stool (poop) of someone who has the infection. Sexual activity where there may be mouth contact with stool can also result in infection. A person can spread the parasite even if they do not have any symptoms.


What are the symptoms of amebiasis?

Only about 10 to 20% of people with amebiasis get symptoms. If symptoms occur, they include diarrhea, flatulence (gas), stomach cramps, and weight loss. The stool (poop) may contain blood, mucus, or pus. In rare cases, the parasite can spread to the other parts of the body.

How soon after you come in contact the parasite will infection occur?

Infections usually occur within one to four weeks after exposure. Sometimes it can take longer.

How long can an infected person carry this parasite?

A person with amebiasis can carry the parasite for weeks, months, or even years. Treatment is the only way to get rid of this parasite.

Testing & prevention

How do I know if I have amebiasis?

If you suspect an infection, see a health care provider. Your health care provider will test your stool sample. It may be necessary to repeat the stool tests a couple of times on different days. A blood test is available but is only needed if your health provider suspects that the infection has spread to another part of your body.

How can you prevent amebiasis?

You can prevent amebiasis by practicing good hygiene and by using caution before eating food or drinking water from an unknown source. Some general guidelines are:

  • Always wash your hands thoroughly with soap and water before meals, before preparing food, after using the toilet, after changing diapers or after helping others use the toilet
  • Do not drink untreated water from a pond, lake or stream. The water may appear clear but it could be contaminated with human waste. If only untreated water is available, boil it for at least 1 minute before using it. Many water purification tablets do not work against this parasite
  • Thoroughly wash all raw fruits and vegetables
  • If you care for a person with amebiasis, scrub your hands with plenty of soap and water after you have helped them to the toilet. Throw away any materials that may have been contaminated with stool. Always wash your hands after such contact
  • Areas with poor sanitation have a higher risk for amebiasis. Travelers to these areas should only drink water or use ice from clean sources (i.e. bottled water). Do not eat unpasteurized milk or dairy products, uncooked fruits, salads and raw vegetables. Also avoid food sold by street vendors
  • Always use protection, such as condoms and/or dental dams, when performing sexual activities that involve fecal-oral contact


What is the treatment for amebiasis?

A doctor can give medicine to treat this infection.

Are there any health regulations for people with amebiasis?

Yes. Health care providers and laboratories in Boston must report cases of amebiasis to the Boston Public Health Commission. 

To protect the public, workers in food-related businesses who have amebiasis must stay out of work until diarrhea is gone and a stool sample for amebiasis is negative. Food-related businesses include restaurants, sandwich shops, supermarkets, dairies, food processing plants, and others. This regulation also includes workers in schools, residential programs, day-care and health care facilities who feed, give mouth care or dispense medication to clients.

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