About Amebiasis

Amebiasis is an intestinal illness that's typically transmitted when someone eats or drinks something that's contaminated with a microscopic parasite called Entamoeba histolytica (E. histolytica). The parasite is an amoeba, a single-celled organism. That's how the illness got its name — amebiasis.

In many cases, the parasite lives in a person's large intestine without causing any symptoms. But sometimes, it invades the lining of the large intestine, causing bloody diarrhea, stomach pains, cramping, nausea, loss of appetite, or fever. In rare cases, it can spread into other organs such as the liver, lungs, and brain.

Amebiasis typically occurs in areas where living conditions are crowded and where there is a lack of adequate sanitation. The illness is very prevalent in parts of the developing world, including Africa, Latin America, India, and Southeast Asia. It is rare in the United States, occurring mostly in immigrants, recent travelers to high-risk countries, and people with HIV/AIDS.

Signs and Symptoms

Most kids who get amebiasis have minimal or no symptoms. When children do become ill, they experience abdominal pain that begins gradually, along with frequent loose or watery bowel movements, cramps, nausea, and a loss of appetite. In some cases they develop a fever and, possibly, bloody stools.

For some people, symptoms of amebiasis can begin within days to weeks of swallowing food or water contaminated by amoebas. For other people, symptoms of amebiasis either take months to appear or never appear at all.

Contagiousness

Amebiasis is contagious. Wherever living conditions are unsanitary and hygiene is poor, the chances are higher that the infection will pass from person to person.

Someone carrying amoebas in his or her intestines can pass the infection to others through the stool. When infected stool contaminates food or water supplies, amebiasis can spread quickly to many people at once. This is especially true in developing countries where drinking water may be contaminated.

Amebiasis can also be spread between people through inadequate hand washing, by using the same objects, and by sexual contact.

Prevention

There is no vaccine to prevent amebiasis.

Because amoebas may contaminate food and water, you can help prevent the illness by being cautious about what you eat and drink, especially in developing countries, where a good rule regarding food is to cook it, boil it, peel it, or forget it.

Treatment

If your doctor suspects that your child has amebiasis, you may be asked to collect stool samples. After diagnosis, treatment will usually require consultation with appropriate experts such as those at the Centers for Disease Control and Prevention (CDC) or other infectious disease specialists.

When to Call the Doctor

Call your doctor if your child has signs or symptoms of amebiasis, including:

• diarrhea with blood or mucus
• abdominal pain
• fever
• distended abdomen
• pain or tenderness in the area of the liver (below the ribs on the right side)

This is especially important if you have recently traveled to a part of the world where amebiasis is common. Your child should also be examined if he or she has persistent diarrhea without any other symptoms.

Reviewed by: Joel Klein, MD
Date reviewed: September 2010