Amebiasis is an infection of the gastrointestinal system that is spread by ingesting food or water contaminated by human waste.
Amebiasis is an infection of the intestinal tract caused by a one-celled parasite called
Entamoeba. Although most cases have no symptoms, the infection can cause diarrhea that ranges from mild to serious. Amoeba can also cause abscesses, especially in the liver. It is not common in Canada. It occurs more often in parts of the world where sanitation systems are less reliable, such as Mexico, Central America, western South America, southern Asia and western and southern Africa. Travellers to these areas are at risk of becoming infected if they consume contaminated food or drinking water. Occasionally Amebiasis can be spread through sexual activity or in group settings like child care facilities.
Only about 10% of people who are infected with Entamoeba become sick. People who do become sick usually develop symptoms within two to four weeks, although symptoms may occasionally take longer to show up. The symptoms are often mild and develop over one to three weeks.
These symptoms include mild stomach pain, stomach cramps, diarrhea, possibly containing blood or mucus, and sometimes alternating with constipation.
Amebic dysentery is a severe form of amebiasis associated with stomach pain, bloody stools, mucoid diarrhea (mucus in stool), and fever. Rarely, Entamoeba invades the liver and forms an abscess. Even less commonly, it spreads to other parts of the body, such as the lungs or brain.
Amebiasis is caused by single-celled parasites called Entamoeba, including the species histolytica.
Entamoeba histolytica is the organism that is associated with severe disease and abscesses. It is found only in humans.
Amebiasis is caused by eating stool (poop) contaminated with the parasite. This can happen through:
- Ingesting food or water contaminated by human waste.
- Touching contaminated surfaces or objects and then touching your mouth.
- Through anal-oral sexual practices.
The pathogen can invade the body's tissues (via the blood), and result in liver, lung or brain abscesses.
Ulceration (sores) can also occur in the skin around the anus.
Diagnosis is usually made by testing of stool samples. Depending on the symptoms and location of disease, a blood test or microscopic examination of portions of infected tissue may be necessary to confirm disease.
Treatment may include antimicrobial medication to ensure that any amoebae in the infected tissues are killed. It also requires a medication that stays in the intestine to make sure any remaining amoebae are killed.
Avoid exposure to human waste.
Always
wash your hands with soap and warm water for 30 seconds before preparing food and after using the toilet. Help children and others who cannot wash their hands on their own to do the same.
Use caution when travelling where food or water may be unsafe and there is poor sanitation.- Drink only treated or boiled water. Disinfect water by using an appropriate iodine solution or by boiling for one minute; two minutes if you are at an altitude of 2000 metres or more. Drinking water from sealed water bottles is also an option. See
HealthLink BC File #49b: How to Disinfect Drinking Water.
- Eat only cooked hot foods or fruits you peel yourself
