| Amoebiasis | |
|---|---|
| Other names | Amoebic dysentery, amebiasis, entamoebiasis[1][2] |
 | |
| The life-cycle of various intestinal Entamoeba species | |
| Specialty | Infectious disease |
| Symptoms | Bloody diarrhea, abdominal pain[3] |
| Complications | Severe colitis, colonic perforation, anemia[3] |
| Causes | Amoebas of the Entamoeba group[3] |
| Diagnostic method | Stool examination, antibodies in the blood[3] |
| Differential diagnosis | Bacterial colitis[3] |
| Prevention | Improved sanitation[3] |
| Treatment | Tissue disease: metronidazole, tinidazole, nitazoxanide, dehydroemetine, chloroquine, Intestinal infection: diloxanide furoate, iodoquinoline[3] |
| Frequency | ~480 million[3] |
Amoebiasis, also known amoebic dysentery, is an infection caused by any of the amoebae of the Entamoeba group.[3] Symptoms are most common during infection by Entamoeba histolytica.[3] Amoebiasis can be present with no, mild, or severe symptoms.[3] Symptoms may include abdominal pain, diarrhea, or bloody diarrhea.[3] Complications can include inflammation and ulceration of the colon with tissue death or perforation, which may result in peritonitis.[3] People affected may develop anemia due to loss of blood.[3]
Cysts of Entamoeba can survive for up to a month in soil or for up to 45 minutes under fingernails.[3] Invasion of the intestinal lining results in bloody diarrhea.[3] 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.[3] Liver abscesses can occur without previous diarrhea.[3] Diagnosis is typical by stool examination using a microscope, but may not reliably exclude infection or separate between specific types.[3] An increased white blood cell count may be present in severe cases.[3] The most accurate test is finding specific antibodies in the blood, but it may remain positive following treatment.[3] Bacterial colitis can result in similar symptoms.[3]
Prevention of amoebiasis is by improved sanitation, including separating food and water from faeces.[3] There is no vaccine.[3] There are two treatment options depending on the location of the infection.[3] Amoebiasis in tissues is treated with either metronidazole, tinidazole, nitazoxanide, dehydroemetine or chloroquine, while luminal infection is treated with diloxanide furoate or iodoquinoline.[3] Effective treatment against all stages of the disease may require a combination of medications.[3] Infections without symptoms do not require treatment but infected individuals can spread the parasite to others and treatment can be considered.[3] Treatment of other Entamoeba infections apart from E. histolytica is not needed.[3]
Amoebiasis is present all over the world,[4] though most cases occur in the developing world.[5] About 480 million people are currently infected with about 40 million new cases per year with significant symptoms.[3][6] This results in the death of between 40,000–110,000 people a year.[3] Most infections are now believed due to E. dispar.[3] E. dispar is more common in certain areas and symptomatic cases may be less common than previously reported.[3] The first case of amoebiasis was documented in 1875 and in 1891 the disease was described in detail, resulting in the terms amoebic dysentery and amoebic liver abscess.[3] Further evidence from the Philippines in 1913 found that upon swallowing cysts of E. histolytica volunteers developed the disease.[3]