-Dr.Manoj Kuriakose
B.H.M.S

What is it?
Amoebiasis is a disease caused by a single-celled parasite called Entamoeba histolytica. Entamoeba histolytica is the third leading cause of morbidity and mortality due to parasitic disease in humans (after malaria and schistosomiasis) and is estimated to be responsible for between 50,000 and 100,000 deaths worldwide every year.

What is Entamoeba Histolytica?
It is a tiny single celled creature, 10 to 40 milli microns in diameter. It is normally a resident of   large intestine of man. While it remains free in the intestines, the person is symptom less, but when it invades the mucous membrane of later, it gives rise to amoebic dysentery.

 Life cycle of the parasite consists of two stages. The first form is called as the Tropozoit , in which form the parasite stays in the intestines. The second form is called Cyst, as which the parasite is excreted out of human body through the feaces. The cyst may survive well outside the human body in feaces, uncooked or contaminated food stuffs and water.

  Where else can the parasite cause infection?
 Apart from the intestine, where it causes Amoebic dysentery, the parasite can also infect the liver. In cases of prolonged and severe infection with it, the parasite reaches the liver to cause liver abscess.

  Who is at risk of amoebiasis?
 Although anyone can have this disease, it is most common in people who live in developing countries that have poor sanitary conditions, poor standards of personal and food hygiene.  It also is found in people who have traveled to developing countries and in people who live in institutions that have poor sanitary conditions.  

How can I become infected with E. histolytica?

·        By putting anything into your mouth that has touched the stool of a person who is infected with E.  Hstolytica.

·        By swallowing something, such as water or food, which is contaminated with E. histolytica.

·        By touching and bringing to your mouth cysts (eggs) picked up from surfaces that are contaminated with E. histolytica

What are the symptoms of amoebiasis?
On average, about one in 10 people who are infected with E. histolytica becomes sick from the infection. The symptoms often are quite mild and can include loose stools, stomach pain, and stomach cramping.

Intestinal amoebiasis or Amoebic dysentery:  This usually runs a chronic course with some or all of following symptoms  

·        grumbling abdominal pains

·        increased urgency and frequency of stools

·        two or more unformed stools a day

·        periods of diorrhoea alternating with constipation

·        mucous and\or blood mixed stools

·        tenderness in the lower abdominal region

·        bloating of abdomen with gas

·        abdominal cramps and tenesmus

·        low grade fever                                                

Hepatic Amoebiasis or Amoebic liver abscess:
 This often occurs without a history of recent diorrhoea and occurs in cases with chronic infection with entamoeba histolytica. An abscess is formed in liver in this condition and it manifests as

·        discomfort and tenderness in right side of chest in the region of liver

·        pain in right shoulder

·        swinging temperature and sweating

·        cough, malaise and loss of appetite

If I swallowed E. histolytica, how quickly would I become sick?

Usually 1 to 4 weeks later but sometimes more quickly or more slowly

 How is amoebiasis diagnosed?
Usually the typical set of symptoms is sufficient to suspect the infection with entamoeba histolytica but following investigations confirm its existence in the infected person.

Intestinal Amoebiasis:

·        Stool examination for presence of parasite in it.

·        sigmoidoscopy: viewing the distal part of large intestine for presence of ulcers on its walls

·        examination of scrapings of walls of large intestines for presence of parasite in its cells

 Of the entire above investigations usually first one suffices to confirm the infection.

Hepatic Amoebiasis:

·        X-Ray chest to view single or multiple abscesses in liver

·        Ultrasonography of liver

·        examination of aspirate from liver

·        Blood examination shows increased neutrophill count

 Should I be concerned about spreading infection to the rest of my household?

Yes. However, the risk of spreading infection is low if the infected person is treated with appropriate medicines and practices good personal hygiene. This includes thorough hand washing with soap and water after using the toilet, after changing diapers, and before handling food.