Amoebiasis - Overview, Symptoms, causes

Life Cycle of Entamoeba Histolytica ( Amoebiasis)

Entamoeba histolytica has a simple life cycle involving two main stages: the infectious cyst and the active trophozoite. Infection begins when cysts are ingested through contaminated food or water and excyst in the intestine, releasing trophozoites that invade tissues.

• The life cycle of Entamoeba histolytica is quite simple and consists of the infective cyst and invasive trophozoite stages.

• The life cycle is completed in a single host, i.e., human

• Humans get infected with cysts of E. histolytica from contaminated food and water. Infection can also be acquired directly by anogenital or oro-genital sexual contact.

• The mature cyst is resistant to the low pH of the stomach, so it remains unaffected by the gastric juices.

• The cyst wall is then lysed by intestinal trypsin, and when the cyst reaches the caecum or lower part of the ileum, excystation occurs. The neutral or alkaline environment, along with the bile component, causes excystation.

• Excystation of a cyst produces 8 trophozoites. Trophozoites are active and carried to the large intestine by the peristalsis of the small intestine. Trophozoites mature and divide by binary fission.

• The trophozoites attach to the mucus lining of the intestine by lectin and secrete proteolytic enzymes, which cause tissue destruction and necrosis. When the parasite gets access to blood, it migrates and causes extra-intestinal diseases.

• When the load of trophozoites increases, some of the trophozoites stop multiplying and revert to cyst form by the process of encystation.

• These cysts are released in faeces, completing the life cycle.

Also Read:

• Kingdom Monera, Protista And Fungi

• Basis of Biological Classification

• Virus

Pathway of Amoebiasis in the Human Body

After ingestion, cysts pass through the stomach and release trophozoites in the intestine, where they multiply and may invade the intestinal wall. In severe cases, they can enter the bloodstream and spread to the liver or other organs. This disease is generally caused by a protozoan named Entamoeba histolytica.

High-Risk Groups for Amoebiasis

People living in poor sanitary conditions, travellers to endemic areas, immunocompromised individuals, and institutionalised persons are at higher risk of developing amoebiasis. Amoebiasis is caused by several reasons, some of the major ones discussed below. There are certain conditions which allow the parasite to grow and spread the Amoebiasis disease.

• People who come from areas that have poor sanitary conditions.

• People who are living in developing areas lack clean water and proper sanitation infrastructure.

• Healthcare workers who are exposed to infected patients or contaminated environments.

• Food handlers who are in contact with contaminated food, especially in underdeveloped areas.

• People engaged in oral-anal sexual practices with the infected person.

• People who have weak immune systems and are prone to other diseases also have a high risk of Amoebiasis.

Symptoms of Amoebiasis

Common symptoms include abdominal pain, diarrhoea (which may be bloody), fever, fatigue, and weight loss. In severe cases, it may lead to liver abscesses and intestinal perforation. Symptoms of Amoebiasis are often confused with different diseases. Some of the major symptoms and their explanations are given below:

Diagnosis of Amoebiasis

Infection of Amoebiasis can occur in several parts of the body. This is the only reason why several tests and diagnosis methods are used to get accurate treatment. Some of the major ones are described below:

Prevention of Amoebiasis

There is no certain way through which you can completely avoid Amoebiasis. But there are certain measures which you can take to prevent Amoebiasis. Some of these are mentioned below:

• Access to safe and clean drinking water.

• Hands must be washed regularly with soap and water.

• Avoid consuming food from unhygienic places.

• Avoid eating foods which are unwashed and produced raw.

• Use proper sanitation facilities.

• Dispose of the sewage properly to prevent contamination.

Medications for Amoebiasis

Amoebiasis is normally treated with a combination of different medicines at the same time. It is generally advised to visit a doctor to eradicate the parasite from your intestine and also other infected tissues and organs. Some of the commonly used medications are mentioned below:

• Metronidazole or Tinidazole: Generally used to kill the E. histolytica present in the intestine and other tissues.

• Paromomycin: One of the luminal agents which is used to eradicate parasites from the intestine.

• Diloxanide Furoate: Another luminal agent which is used for eliminating cyst carriers.

• Dehydroemetine: Used in severe cases of extraintestinal Amoebiasis and especially in the case of liver Abscess.

• Chloroquine: Used in combination with other drugs to treat Liver Abscess

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