Prevalence of antibodies against Entamoeba histolytica in Mexico measured by ELISA (original) (raw)
Related papers
Amoebiasis as a Major Risk to Human Health: A Review
International Journal of Molecular Medical Science, 2013
Entamoeba histolytica has diverse distribution and is a substantial risk in almost all the countries where barrier between human feces, food and water source are ordinary. There are at least 8 different amoebas that live in the human intestinal lumen however those are generally accepted as commensals except for E. histolytica. The parasite imposes a major threat to public health in most parts of world and has re-emerged in some previously dormant areas as it is categorized as second leading cause of death from parasitic disease worldwide. In most of E. histolytica infection, symptoms remain absent or very mild whereas most frequent clinical manifestation are colitis and liver abscess due to amoebic infection. Laboratory diagnosis of amoebiasis is usually made on the basis of microscopical and serological methods Nitromidazole derivatives like metronidazole, tinidazole and ornidazole are considered as foundation stone of the treatment for amoebiasis. Lack of effective vaccination is one of the major hurdles for the control of amoebiasis that may prevent transmission of the parasite and or at least progression of the infected individuals into active invasive disease. The aim of this article is to comprehensively review the epidemiology, disease pathology and treatment of this parasitic zoonotic disease. Keywords Amoebiasis; Entamoeba histolytica; Food and water borne; Parasitic disease .
Clinical and diagnostic laboratory immunology, 1994
Prominent antigens of pathogenic and nonpathogenic free-living amoebae were identified by using polyclonal rabbit immune sera in immunoblot assays. The intent was to determine if prominent epitopes identified with rabbit immune sera could also be recognized by human sera. With rabbit sera, the development of immunoreactive bands was restricted to molecular masses of greater than 18.5 kDa forNaegleria, Hartmannella, and Vahlkampfia antigens. Two or more broad bands of less than 18.5 kDa were prominent features in three different Acanthamoeba species. Few cross-reactive antibodies could be detected between representative species of the three different subgroups ofAcanthamoeba. Naegkria antigen was likewise serologically distinct, as were Hartmannella and Vahlkampfia antigens. The relative lack of cross-reacting antibodies between the pathogenic amoebae suggested that it would be desirable to use a panel of amoebic antigens to represent the range of serologically distinct antigens for assessing reactive antibodies in human sera. In pooled human serum (10 serum specimens per pool), the appearance of minimally reactive bands ranging from 32.5 to 106 kDa was a common feature of all six antigens. A prominent band of less than 18.5 kDa was identified in the Acanthamoeba culbertsoni antigen lane in 2 of the 10 human serum specimen pools. When the sera from each of the two groups were tested individually by immunoblotting, the reaction with theA. culbertsoni antigen could be associated with one individual. By using a panel of amoebic antigens, this method could prove useful in recognizing undiagnosed amoebic infections by revealing specific reactive antibodies.
Update on laboratory diagnosis of amoebiasis
European Journal of Clinical Microbiology & Infectious Diseases, 2018
Amoebiasis, an enteric protozoan disease caused by Entamoeba histolytica, is a public health problem in many developing countries, causing up to 100,000 fatal cases annually. Detection of the pathogenic E. histolytica and its differentiation from the non-pathogenic Entamoeba spp. play a crucial role in the clinical management of patients. Laboratory diagnosis of intestinal amoebiasis in developing countries still relies on labour-intensive and insensitive methods involving staining of stool sample and microscopy. Newer and more sensitive methods include a variety of antigen detection ELISAs and rapid tests; however, their diagnostic sensitivity and specificity seem to vary between studies, and some tests do not distinguish among the Entamoeba species. Molecular detection techniques are highly sensitive and specific and isothermal amplification approaches may be developed into field-applicable tests; however, cost is still a barrier for their use as a routine laboratory test method in most endemic areas. Laboratory diagnosis of extraintestinal amoebiasis faces challenges of lack of definitive detection of current infection and commercially available point-of-care tests. For both types of amoebiasis, there is still a need for highly sensitive and specific tests that are rapid and cost-effective for use in developing countries where the disease is prevalent. In recent years, new molecules of diagnostic value are being discovered and new tests developed. The advances in 'omics' technologies are enabling discoveries of new biomarkers that may help distinguish between different infection stages.
The aim of this study was to differentiate Entamoeba dispar from Entamoeba histolytica by PCR directly from fresh stool. Background: Microscopy does not allow for the differentiation of Entamoeba dispar from Entamoeba histolytica. Several PCR-based methods have been described and used successfully for this purpose, but the methods for DNA extraction from stool samples are usually time-consuming and problematic due to inhibitory factors in feces. Patients and methods: From a total of 1700 stool samples collected and examined by microscopy, 22 samples (1.3%) were microscopically positive for the E. histolytica /E. dispar complex. The DNA of these samples was extracted directly from fresh stool and PCR was carried out using two sets of species-specific primers from a short tandem repeat (STR) in the D-A locus. Results: Of these, 21 samples (95.45%) were diagnosed as E. dispar and only one sample (4.55 %) was found to be E. histolytica. In this study, by improving the DNA extraction from fresh stool, we were able to efficiently differentiate E. histolytica and E. dispar. Conclusion: To avoid unnecessary treatment of patients not infected with E. histolytica, the development of effective techniques, such as direct DNA extraction from stool, is recommended.
Novelties on amoebiasis: A neglected tropical disease
Journal of Global Infectious Diseases, 2011
In accordance with the 1997 documents of the World Health Organization (WHO), amoebiasis is defined as the infection by the protozoan parasite Entamoeba histolytica with or without clinical manifestations. The only known natural host of E. histolytica is the human with the large intestine as major target organ. This parasite has a very simple life cycle in which the infective form is the cyst, considered a resistant form of parasite: The asymptomatic cyst passers and the intestinal amoebiasis patients are the transmitters; they excrete cysts in their feces, which can contaminate food and water sources. E. histolytica sensu stricto is the potentially pathogenic species and E. dispar is a commensal non-pathogenic Entamoeba. Both species are biochemical, immunological and genetically distinct. The knowledge of both species with different pathogenic phenotypes comes from a large scientific debate during the second half of the 20 th century, which gave place to the rapid development of diagnostics technology based on molecular and immunological strategies. During the last ten years, knowledge of the new epidemiology of amoebiasis in different geographic endemic and non-endemic areas has been obtained by applying mostly molecular techniques. In the present work we highlight novelties on human infection and the disease that can help the general physician from both endemic and non-endemic countries in their medical practice, particularly, now that emigration is undoubtedly a global phenomenon that is modifying the previous geography of infectious diseases worldwide.
The Journal of Infectious Diseases, 2001
Amebiasis is the third leading parasitic cause of death worldwide, and it is not known whether immunity is acquired from a previous infection. An investigation was done to determine whether protection from intestinal infection correlated with mucosal or systemic antibody responses to the Entamoeba histolytica GalNAc adherence lectin. E. histolytica colonization was present in 0% (0/64) of children with and 13.4% (33/246) of children without stool IgA anti-GalNAc lectin antibodies (). Children with stool IgA lectin-specific P p .001 antibodies at the beginning of the study had 64% fewer new E. histolytica infections by 5 months (3/42 IgA + vs. 47/227 IgA Ϫ ;). A stool antilectin IgA response was detected P p .03 near the time of resolution of infection in 67% (12/18) of closely monitored new infections. It was concluded that a mucosal IgA antilectin antibody response is associated with immune protection against E. histolytica colonization. The demonstration of naturally acquired immunity offers hope for a vaccine to prevent amebiasis. Amebiasis is estimated to result annually in 50 million cases of colitis and liver abscess and 100,000 deaths [1]. A major impediment to developing a vaccine is the lack of knowledge of the existence or nature of acquired immunity. Recent recognition of the distinction between invasive Entamoeba histolytica and noninvasive E. dispar has made many earlier studies of human immunity uninterpretable, since E. histolyticaspecific diagnostic tests were not used [1-3]. Case series of patients with amebic colitis in Natal, South Africa, and Dhaka, Bangladesh, show that there is a peak incidence of infection among children !14 years of age and a second increase in infection in adults 140 years old [4, 5]. This could be interpreted as evidence of acquired childhood immunity that wanes with advancing age. The development of invasive amebiasis in some E. histolytica-colonized individuals and documented second in
Seroprevalence of anti-amoebic antibody among blood donors by indirect hemeagglutination assay
Tropical biomedicine, 2009
The screening for anti-amoebic antibody among a group of donors was to obtain negative control serum samples for an on-going antigen development assay in diagnosis of amoebic liver abscess. Out of 200 samples, 125 (62.5%) were negative, whereas 44 (21.5%) had IHA titer of less than 1:128 and 31 (16.0%) of the samples had significant IHA titers of 1:128 or more, in which 2 serum samples gave titers of 1:4096.
Amoebiasis Distribution In the Past: First Steps Using An Immunoassay Technique
Transactions of the …, 2004
The identification of parasites in ancient human faeces is compromised by differential preservation of identifiable parasite structures. However, protein molecules can survive the damage of the environment and can be detected even after centuries. In this paper it is shown that is possible to detect copro-antigen of Entamoeba histolytica in historic and prehistoric human faecal remains, using a commercially available enzyme immunoassay (ELISA) kit. The kit uses monoclonal antibody-peroxidase conjugate specific for E. histolytica adhesin. A total of 90 specimens of desiccated faeces found in mummies and ancient organic sediment from South America, North America, Africa, and Europe were examined. The ELISA detected 20 positive samples, dated to about 5300 years before present to the 19th Century ad. The positive samples are from archaeological sites in Argentina, USA, France, Belgium, and Switzerland. The detection of protozoan antigen using immunoassays is a reliable tool for the studies of intestinal parasites in the past.