Entamoeba dispar is morphologically identical but is not associated with disease. Intestinal entamoeba histolytica amebiasis uptodate. Background entamoeba histolytica entamoeba dispar entamoeba moshkovskii infection is still prevalent in rural malaysia especially among orang asli communities. Apr 15, 20 serosurvey of entamoeba histolytica exposure among tepehuanos population in durango, mexico. Amebiasis, amebic dysentery, ameboma characteristics. During the last decade, entamoeba moshkovskii became relevant because of its ability to infect humans. Entamoeba histolytica is an invasive, pathogenic protozoan, causing amoebiasis, and an important cause of diarrhea in developing countries. Laboratory diagnostic techniques for entamoeba species clinical. The gastrointestinal pathogen entamoeba histolytica causes amoebiasis.
Progress in the epidemiology of amoebiasis has not only suffered from the impossibility of. Further molecular studies have identified a third species, e. The prevalence of entamoeba infection is as high as 50% in areas of central and south america, africa, and asia. Entamoeba dispar appears to be about 10 times more common than e. Prevalence of antibodies against entamoeba histolytica in. Entamoeba histolytica is the causative agent of amebiasis and is globally considered a. Amebiasis entamoeba histolytica infection definition. Currently, information on prevalence of this infection among different ethnic groups of orang asli is unavailable in malaysia.
Entamoeba histolytica is an anaerobic intestinal amoeba parasite that predominantly affects a man and causes amoebic dysentery and liver abscess history. These pathogen safety data sheets, regulated under workplace hazardous materials information system whmis legislation, are produced for personnel working in the life sciences as quick safety reference material relating to infectious microorganisms. The study objective was to assess risk factors of e. Entamoeba histolytica and another ameba, entamoeba dispar, which is about 10 times more common, look the same when seen under a microscope. The prevalence of antibodies against entamoeba histolytica was studied in the mexican population using an immunoenzyme assay in solid phase elisa and semiautomatic equipment. To contribute to a better comprehension of the epidemiology of this infection, a crosssectional study aimed. Recent studies have revealed opportunities to produce an effective vaccine against the entamoeba histolytica infection. Amebiasis chapter 4 2020 yellow book travelers health. To investigate the molecular epidemiology of entamoeba histolytica. Longterm travelers duration 6 months are significantly more likely than shortterm travelers duration histolytica infection. Pathogenesis and immune response toward entamoeba histolytica. In the precystic forms, entamoeba remains only in the intestinal lumen. In most infected individuals the trophozoites exist as commensals. Traditionally, about onetenth of the world population is stated to be infected with e.
First molecular epidemiology of entamoeba histolytica, e. Risk factors for entamoeba histolytica infection in an. Entamoeba moshkovskii perspectives of a new agent to be considered in the diagnosis of amebiasis. Oti and others published understanding the epidemiology of entamoeba histolytica infections find, read and cite all the research you need on researchgate. Entamoeba histolytica and entamoeba dispar basic guidelines a. A higher prevalence in tropical and subtropical countries 10 % of the world population carries the parasite. Objectives to investigate the molecular epidemiology of entamoeba histolytica, e. It exists in two formsthe trophozoite which is the active, dividing form, and the cyst which is dormant and can survive for prolonged periods outside the host. Determination of the prevalence of entamoeba amiga and e.
Clinical severity ranges from the asymptomatic passage of cysts in the stool to fulminant dysentery. Although many people harbour this organism world wide, only about 10% develop clinically. The antigen was a mixture of membrane proteins obtained by triton x100 extraction from an axenic culture of entamoeba histolytica hm1imss. Multiple stool samples at least 3 should be tested before a negative result is reported. Of these entamoeba histolytica is the only species found to be associated with intestinal disease. Epidemiology sections of the american public health. Laboratory diagnostic techniques for entamoeba species. For a long time, it was considered to simply be a freeliving amoeba.
Entamoeba histolytica material safety data sheet infectious substances section i infectious agent name. Amebiasis is distributed worldwide, particularly in the tropics, most commonly in areas of poor sanitation. The epidemiology of entamoeba histolytica infection in sudan is poorly understood. Entamoeba histolytica introduction there is a large number of species of amoebae which parasitise the human intestinal tract. In endemic developing countries where resources are limited, microscopic examinations based on wheatley trichrome staining is commonly used for diagnosis of intestinal amoebiasis. Potentially fatal extraintestinal amoebiasis, including amoebic liver abscess, complicates 1%3% of infections. Molecular epidemiology and genetic diversity of entamoeba. Amebiasis is an intestinal illness caused by a microscopic parasite called entamoeba histolytica. Prevalence and clinical importance of entamoeba histolytica in two. Entamoeba histolytica has a worldwide distribution and is. The world health organization has recommended that e.
Entamoeba histolytica causes about 50 million infections worldwide with a death rate of over 100,000 annually. Epidemiology of entamoeba histolytica worldwide distribution. Entamoeba histolytica causes amebic colitis and liver abscess in developing countries such as mexico and india. Entamoeba histolytica was first discovered by losch in 1875 in leningrad, russia for causing disease in humans. To maximize recovery of cysts, stool samples in formalin, or other fixatives, should be concentrated prior to microscopic examination e. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. They undergo encystment but before encystment, the parasites round up, eliminate food vacuoles and accumulate considerable amount of food materials in the form of glycogen and black rodlike chromatoid granules.
The epidemiology of entamoeba histolytica has been complicated by the mid1990s redescription of e. Entamoeba histolytica is an intestinal protozoan parasite and the causative agent of invasive amebiasis. Entamoeba histolytica is a protozoan parasite that causes amebic dysentery and liver abscess. Present characteristics of symptomatic entamoeba histolytica. Entamoeba histolytica is the responsible parasite of amoebiasis and. The disease is common in tropical regions of the world where hygiene and sanitation is often approximate. Our understanding of its epidemiology has dramatically changed since this amoeba was distinguished from another morphologically similar one, entamoeba dispar, a non. Alvaradoesquivel c, hernandeztinoco j, francisco sanchezanguiano l, ramosnevarez a, margarita cerrillosoto s, alberto guidoarreola c. It begins when a person drinks contaminated water or eats foods contaminated with the cystic form infective stage, comes in contact with contaminated colonic irrigation devices or the fecally contaminated hands of food handlers, or by oralanal sexual practices. Epidemiology of amebiasis in the us jama jama network.
Pdf molecular epidemiology of amoebiasis in malaysia. Epidemiology and comparison of diagnostic methods in a setting of nonendemicity. The cause of amebiasis is infection by the protozoan parasite entamoeba histolytica. Entamoeba histolytica is a protozoan parasite that causes amoebiasis.
Recent immigrants and refugees from these areas are also at risk. Highlighting the different risk factors of entamoeba histolytica and entamoeba dispar infections among orang asli communities. Ed sc reg no i56ce9242009 a thesis submitted in partial fulfillment of the requirements for the award of. Entamoeba histolytica global water pathogen project. Identification of entamoeba histolytica trophozoites in fresh. Laboratory methods of identification of entamoeba histolytica and its differentiation from lookalike entamoeba spp. This study investigated the presence of entamoeba histolytica, entamoeba dispar, and entamoeba moshkovskii in stool samples from a patient population in.
Entamoeba histolytica, a protozoan parasite, is the etiologic agent of amoebiasis in humans. Differentiation of entamoeba histolytica and entamoeba dispar from german travelers and residents of endemic areas. Evaluation of entamoeba histolytica antigen and antibody point of care tests for the rapid diagnosis of amebiasis. Molecular epidemiology and genetic diversity of entamoeba species in a chelonian collection gabriela garcia 1, fernando ramos 1, rodrigo gutierrez perez 1, jorge yanez 2, monica salmeron estrada 3, lilian hernandez mendoza 1, fernando martinezhernandez 4, paul gaytan 2. Entamoeba histolytica is an amoeba with worldwide distribution, transmitted through the fecaloral route sakakibara et al. The structure and life cycle of entamoeba with diagram. About 10% develop invasive amoebiasis, which leads to 40 000110 000 deaths per annum. Prevalence and risk factors associated with entamoeba. Application of this method to the epidemiology of human intestinal protozoa e. Pathogenesis of infection by entamoeba histolytica springerlink. Infection with entamoeba histolytica has the potential to cause dysentery and extraintestinal disease. Pdf understanding the epidemiology of entamoeba histolytica.
Epidemiology of amebiasis american journal of public health. Molecular epidemiology of entamoeba spp evidence of a. As our knowledge of the global epidemiology and pathogenicity of entamoeba spp. Sep 01, 2012 progress in the molecular epidemiology of protozoa infection has been driven by developments in the laboratory techniques, such as pcr and other molecular biological tools. Entamoeba histolytica epidemiology a worldwide distribution. Anyone can get amebiasis, but it occurs more often in people arriving from tropical countries that have poor sanitary conditions, in individuals in institutions for the developmentally disabled, and in men who have sex with men. Colonization with the morphologically identical parasite e. Little is known about the epidemiology and incidence of e. In a country as large as the us, with so many different geographical areas and socioeconomic groups, it is probably unwise to give a prevalence figure of entamoeba histolytica for the general population. Entamoeba histolytica and intestinal amoebiasis the nepali. However, since the prevalence rate has been frequently cited to be 10 to 20%, it is well to. Amongst these have been found seven more groups of e. Dpdx is an educational resource designed for health professionals and laboratory scientists.
Entamoeba histolytica amebiasis infectious disease and. Infection with entamoeba histolytica has the potential to cause dysentery and extraintestinal disease, whereas e. Our understanding of its epidemiology has dramatically changed since this amoeba was distinguished from another morphologically similar one, entamoeba dispar, a non pathogenic and commensal parasite. Entamoeba histolytica is an important protozoan intestinal infection in resourcepoor settings, including vietnam. Molecular epidemiology of human intestinal amoebas in iran. A casecontrol study was conducted among residents of hanam province, northern vietnam.