Amoebiasis

Definition

Amebiasis is an infection of the intestine, liver, or other tissues. It is caused by the parasite Entamoeba histolytica. It is characterized by frequent, loose stools flecked with blood and mucus.

Causes

Amebiasis is most prevalent in tropical and subtropical countries where standards of public hygiene and sanitation may be low.

Most of the cases are find in the U.S. and other developed countries travelers who have recently returned from developing tropical or subtropical countries. About 5,000 to 10,000 cases are diagnosed each year in the U.S. and among leading to about 20 deaths annually.

People get amebiasis when they swallow Entamoeba histolytica cysts. This can happen due to:

• Putting anything into the mouth that has touched the stool of an infected person
• Swallowing water or food that has been contaminated with Entamoeba histolytica
• Touching and bringing to the mouth cysts picked up from surfaces contaminated with Entamoeba histolytica.

Symptoms

On average, about one in 10 people who are infected with E. histolytica becomes sick from the infection. Amebic dysentery is a severe form of amebiasis associated with stomach pain, bloody stools, and fever. Rarely, E. histolytica invades the liver and forms an abscess. In rare cases, the parasite spreads outside the intestine to the liver and forms an abscess. Even less commonly, it spreads to other parts of the body, such as the lungs or brain.

 Some people develop a severe form of amebiasis called AMEBIC DYSENTERY.

Some strains of amebae are harmless but others, for unknown reasons, invade the intestinal wall, causing mucus secretion into the intestines and diarrhea - an illness called amebic dysentery. 

In severe cases, ulcers may form in the intestinal wall; the amebae gain access to the bloodstream and travel to the liver to form abscesses.

Sometimes no symptoms are present. When symptoms do appear, they may include:

Abdominal bloating and cramps.

Dehydration.

Gas and foul-smelling stools.

Diarrhea that comes and goes.

Mucus and blood in the stool.

Treatment

Infection is diagnosed by examining a stool sample under a microscope to look for the parasite, because amebiasis can be difficult to diagnose. For examine the actual amebiasis effected patient doctors has need more than one stool sample.

A blood test is available but is recommended only if the patient's health-care provider thinks that the infection has invaded the wall of the intestines or some other organ, such as the liver. Blood tests might be positive if a person had an amebic infection in the past.

Amebiasis can usually be cured with an antimicrobial medication. All children with E. histolytica in their stools should be treated with oral antimicrobial medications prescribed by a doctor, whether they have symptoms or not.