Entamoeba histolytica Amebiasis

Ravdin J. Entamoeba histolytica (amebiasis). In Mandell GL, Dolin R, Bennett JA, eds. Principles and Practice of Infectious Diseases, 5th ed. New York, Churchill-Livingstone, 2000 2798-2810. 

Entamoeba histolytica is an anaerobic rhizopod that occurs in tropical and subtropical areas. It can cause intestinal and extraintestinal manifestations. It is transmitted orally by ingestion of cysts that develop into trophozoites in the large intestine. Amebic trophozoites release several cytolytic factors, e.g. amoe-bapore, which enable the parasite to invade tissue. In intestinal amoebiasis, E. histolyticatrophozoites invade the intestinal mucosa, causing a form of ulcerative colitis with bloody and mucous diarrhoea. Extraintestinal manifestation of amebiasis results in abscess formation, usually in the liver but sometimes in the brain. 

Acute intestinal amebiasis Due to Entamoeba histolytica as adjunct to amebicides. 

Amebiasis For the treatment of intestinal amebiasis and amebic liver abscess caused by Entamoeba histolytica in adults and pediatric patients older than 3 years of age. 

The protozoan Entamoeba histolytica causes amebiasis, an infection that is endemic in parts of the United States. The parasite can be present in the host as either an encysted or a trophozoite form. Initial ingestion of the cyst may result either in no symptoms or in severe amebic dysentery characterized by the frequent passage of bloodstained stools. The latter symptom occurs after invasion of the intestinal mucosa by the actively motile and phagocytic trophozoite form of the protozoan. 

Anti-amoebic activity. Ethanol (80%) extract of the dried rhizome was inactive on Entamoeba histolytica, minimum inhibitory concentration (MIC) greater than 1 mg/ mL The extract, administered intragas-trically to male hamsters at a dose of 800 mg/kg, was active vs experimentally induced hepatic amebiasis . A dose of 250 mg/kg, administered intragastrically to rats on days 1-5, produced weak activity and a dose of 500 mg/kg was active " ". Anti-atherosclerotic activity. Ethanol (50%) extract of the dried rhizome, administered intragastrically to male rabbits at a dose of 500 mg/kg, reduced atherogenic index from 4.7 to 1.2 on the aorta . Antibacterial activity. Decoction of the dried entire plant, on agar plate, was inactive on Proteus vulgaris, Staphylococcus aureus, and Staphylococcus epidermidis MIC 125 mg/mL. Bacillus subtilis, Bordetella... 

Amebiasis is infection with Entamoeba histolytica. This organism can cause asymptomatic intestinal infection, mild to moderate colitis, severe intestinal infection (dysentery), ameboma, liver abscess, and other extraintestinal infections. The choice of drugs for amebiasis depends on the clinical presentation (Table 52-5). 

Amebiasis is an infection of the large intestine produced by Entamoeba histolytica that causes symptoms that range from mild diarrhea to fulminant dysentery. Therapy includes treating the asymptomatic carrier of the cysts, as well as the acute amebic dysentery, and the amebic hepatitis and abscess in the symptomatic patient. 

Amebiasis refers to the infection caused by entamoeba histolytica and is estimated to cause about 70,000 deaths per year worldwide [73]. It is a gastrointestinal infection that may or may not be symptomatic and can remain latent in an infected... 

Amebiasis (also called amebic dysentery) is an infection of the intestinal tract caused by Entamoeba histolytica. The disease can be acute or chronic with patients showing varying degrees of illness, from no symptoms to mild diarrhea to fulminating dysentery. Diagnosis is made by isolating E, histolytica in fresh feces. Therapy is aimed not only at the acutely ill patient but also at those who are asymptomatic carriers since dormant E. histolytica may cause future infections in the carrier and may be a potential source of infection of others. 

Amebiasis. The causative agent, Entamoeba histolytica, lives and multiplies in the colon (symptom diarrhea), its cyst form residing also in the liver among other sites. In tropical regions, up to half the population can be infested, transmission occurring by the fe-cal-oral route. The most effective treatment against both intestinal infestation and systemic disease is administration of metronidazole. If monotherapy fails, combination therapy with chloroquine, emetine or tetracyclines may be indicated. 

Amebiasis is diagnosed by finding the cysts of Entamoeba histolytica in a stool specimen examined under a microscope. Because the number of cysts in the stool can change from day to day, and cysts may not even be in every stool specimen, sometimes more than one stool specimen must be obtained for examination. A blood test is also available for detection of antibodies against the parasite. 

Intestinal amebiasis is diagnosed by demonstrating Entamoeba histolytica cysts or trophozoites (may contain ingested erythrocytes) in fresh stool or from a specimen obtained by sigmoidoscopy. Three stool samples obtained 24 hours apart will produce a 60% to 90% yield for E. histolytica. 

Because of its worldwide distribution and serious gastrointestinal manifestations, amebiasis is one of the most important parasitic diseases of humans. " "" The major causative organism in amebiasis is Entamoeba histolytica, which inhabits the colon and must be differentiated from the E. dispar, which is associated with an asymptomatic carrier state and is considered nonpathogenic. Although E. histolytica and E. dispar are indistinguishable morphologically, recent research... 

Answer C. In amebic dysentery caused by Entamoeba histolytica and GI infections with diarrhea ( back-packer s diarrhea ) due to Giardia lamblia, metronidazole is the drug of choice. Diloxanide is a backup drug for noninvasive intestinal amebiasis, but it has minimal activity in giardial infections. Quinacrine has effectiveness in giardiasis but not amebiasis. TMP-SMX has antiprotozoal effectiveness in Pneumocystis carinii pneumonia. Ciprofloxacin is devoid of antiprotozoal activity. 

Amebiasis is primarily an intestinal disease caused by Entamoeba histolytica, which is a cosmopolitan organism usually transmitted by ingestion of materials contaminated by cysts that descend the GI tract. Trophozoites develop and remain in the colon, caecum, and sigmoidal area. Ulceration of the intestinal wall results, causing symptoms of dysentery. Metastatic lesions sometimes develop in other organs such as the liver (hepatic amebiasis). This is more difficult to treat. Amebicides in use today have all been developed empirically. The nitroimidazoles metronidazole, tinidazole, and the toxic nitro heterocycle niri-dazole (Fig. 7-4) are effective at all sites. 

Echinococcus, see Tapeworm infection Entamoeba histolytica, see Amebiasis... 

Schlesinger, P. (1988) Lysosomes and Entamoeba histolytica. In Amebiasis Human infection with Entamoeba histolytica (ed. Ravdin, J. I.), Wiley, New York, pp. 297-307. 

Ravdin, J. (ed.) (1988) Amebiasis Human Infection by Entamoeba histolytica. John Wiley, New York. 

The confirmed diagnosis of amebic disease justified therapy with metronidazole, which is effective in most cases of extraluminal amebiasis. Oral tetracycline is an inhibitor of bacteria that are associated with Entamoeba histolytica in the gut. 

Amebiasis is a parasitic infection caused by the pro-tozoon Entamoeba histolytica. It is the third leading parasitic cause of death worldwide, surpassed only by malaria and schistosomiasis. Amebiasis can localize in many different locations besides the bowel. One of the most common extraintestinal manifestations is the amebic liver abscess, which usually occurs in children less than 3 years of age, with a peak incidence in the first year of life (Elizondo et al. 1987 Giovagnoni et al. 1993). 

The Skraup reaction was also used for the synthesis of the amebocide drug iodoquinol. Amebiasis is an infection of the body by the protozoa Entamoeba histolytica with symptoms of acute ameba dysentery, which is accompanied by bloody diarrhea, vomiting, fever, and dehydration. Iodoquinol is considered as a drug of choice for treating asymptomatic or moderate forms of amebiasis. Its preparation relies on the reaction of 2-aminophenol with glycerol in the presence of sulfuric acid. ... 

Amoebic dysentery Severe, acute form of amebiasis, caused by Entamoeba histolytica. 

Chronic amebiasis Chronic infection caused by the protozoan Entamoeba histolytica. 

Amebiasis - There have been no real advances made during the past year in the treatment of Entamoeba histolytica. A drug equally effective for the treatment of both systemic cuod Intestinal amebiasis is not available. 

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