Amoebiasis

Amoebiasis, also known amoebic dysentery, is an infection caused by any of the amobae of the Entamoeba group. Symptoms are most common during infection by Entamoeba histolytica. Amoebiasis can be present with no, mild, or severe symptoms. Symptoms may include abdominal pain, diarrhea, or bloody diarrhea. Complications can include inflammation and ulceration of the colon with tissue death or perforation, which may result in peritonitis. People affected may develop anemia due to loss of blood.

Cysts of Entamoeba can survive for up to a month in soil or for up to 45 minutes under fingernails. Invasion of the intestinal lining results in bloody diarrhea. If the parasite reaches the bloodstream it can spread through the body, most frequently ending up in the liver where it can cause amoebic liver abscesses. Liver abscesses can occur without previous diarrhea. Diagnosis is typical by stool examination using a microscope, but may not reliably exclude infection or separate between specific types. An increased white blood cell count may be present in severe cases. The most accurate test is finding specific antibodies in the blood, but it may remain positive following treatment. Bacterial colitis can result in similar symptoms

Symptoms

Infections can sometimes last for years if there is no treatment. Symptoms take from a few days to a few weeks to develop and manifest themselves, but usually it is about two to four weeks. Symptoms can range from mild diarrhea to dysentery with blood, coupled with intense abdominal pains. The blood comes from bleeding lesions created by the amoebae invading the lining of the colon. In about 10% of invasive cases the amoebae enter the bloodstream and may travel to other organs in the body. Most commonly this means the liver, as this is where blood from the intestine reaches first, but they can end up almost anywhere in the body.

Onset time is highly variable and the average asymptomatic infection persists for over a year. It is theorized that the absence of symptoms or their intensity may vary with such factors as strain of amoeba, immune response of the host, and perhaps associated bacteria and viruses.

In asymptomatic infections, the amoeba lives by eating and digesting bacteria and food particles in the gut, a part of the gastrointestinal tract. It does not usually come in contact with the intestine itself due to the protective layer of mucus that lines the gut. Disease occurs when amoeba comes in contact with the cells lining the intestine. It then secretes the same substances it uses to digest bacteria, which include enzymes that destroy cell membranes and proteins. This process can lead to penetration and digestion of human tissues, resulting first in flask-shaped ulcerations in the intestine. Entamoeba histolytica ingests the destroyed cells by phagocytosis and is often seen with red blood cells (a process known as erythrophagocytosis) inside when viewed in stool samples. Especially in Latin America, a granulomatous mass (known as an amoeboma) may form in the wall of the ascending colon or rectum due to long-lasting immunological cellular response, and is sometimes confused with cancer.

Causes

Amoebiasis is usually transmitted by the fecal-oral route, but it can also be transmitted indirectly through contact with dirty hands or objects as well as by anal-oral contact. Infection is spread through ingestion of the cyst form of the parasite, a semi-dormant and hardy structure found in feces. Any non-encysted amoebae, or trophozoites, die quickly after leaving the body but may also be present in stool: these are rarely the source of new infections. Since amoebiasis is transmitted through contaminated food and water, it is often endemic in regions of the world with limited modern sanitation systems, including México, Central America, western South America, South Asia, and western and southern Africa.

Treatment

Generally, amebiasis can be treated by antimicrobial medication: however, in severe cases such as amebic liver abscess hospitalization and surgery is required. In asymptomatic intestinal infection remedy, treatment using diloxanide furoate iodoquinol, paromomycin or metronidazole is quite common. In some milder cases, the condition can be treated with various natural herbs such as Emblica Officinalis, belerica and Eclipta alba. Neem is also considered to be great disinfectant. One can use pills or decoction of those herbs in order to heal the diseases. Buttermilk is also considered to be good replacement therapy in Ayurveda.

In some more severe cases of amoebic dysentery, the treatment involves supplementation of IV fluids with lots of other medications such as antacids, anti-nauseant and anti-spasmodic; they are either given or orally or by injections. In some serious cases, such as hepatic abscess, the patient may require typical removal.

Prevention

  • Wash hands thoroughly with soap and hot running water for at least 10 seconds after using the toilet or changing a baby’s diaper, and before handling food.
  • Clean bathrooms and toilets often; pay particular attention to toilet seats and taps.
  • Avoid sharing towels or face washers.
  • Avoid raw vegetables when in endemic areas, as they may have been fertilized using human feces.
  • Boil water or treat with iodine tablets.
  • Avoid eating street foods especially in public places where others are sharing sauces in one container