Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMEBIASIS, INTESTINAL”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,405 records · Page 78Linked to original sources
PubMed1985

Amoebiasis and its control.

On a global scale, 480 million people were recently estimated to be infected with Entamoeba histolytica and some 48 million people suffer from invasive amoebiasis. The latter, in the intestinal and extra-intestinal forms, accounts for 40 000 to 110 000 deaths annually. In view of this considerable mortality and morbidity, more research is urgently needed so that more effective control strategies may be introduced.This Update article reviews the magnitude of the problem, clinical and laboratory diagnosis, present treatment and prevention measures, possible control strategies, and research priorities.

Amebiasis↗
PubMed1994

Role of mucosal secretory immunity in the development of an amebiasis vaccine.

Invasive colonic infection by the enteric protozoan Entamoeba histolytica elicits a mucosal anti-amebic IgA antibody response. The E. histolytica galactose-inhibitable adherence protein (GIAP) mediates parasite binding to colonic mucins and epithelial cells. Anti-GIAP secretory IgA antibodies are found during invasive amebiasis and can be elicited by immunization of rats with the native protein. Entamoeba histolytica contains potent IgA degradative activities due to its cysteine-specific proteases. Research is needed to further understand the role of secretory antibodies in natural or vaccine-induced immunity to E. histolytica.

Animals↗
PubMed1999

Intestinal amebae.

Although the intestinal amebae that infect humans are not thought of as classic agents of food-borne disease, food plays an important role in the transmission of these protozoa. This is particularly true for areas of the world where the organisms are endemic. Transmission of most intestinal protozoa occurs by the fecal-oral route via contaminated food or water. Among the four genera of amebae that infect man, only Entamoeba histolytica and Blastocystis hominis are causes of disease. This article focuses on E. histolytica because of the organism's medical and economic impact on humans. In addition, the epidemiology, control, and laboratory diagnosis of these protozoa are addressed.

Amebiasis↗
PubMed1996

Antiamoebic activity of Piper longum fruits against Entamoeba histolytica in vitro and in vivo.

The fruits of Piper longum used in traditional remedies against intestinal distress have been tested for their efficacy against experimental caecal amoebiasis of rats. The ethanolic extract, hexane fraction, n-butanol soluble fraction exerted in vitro amoebicidal action at 1000 micrograms/mL and the chloroform fraction at 500 micrograms/mL. The ethanolic extract and piperine, a pure compound, from this plant material cured 90% and 40% of rats with caecal amoebiasis, respectively.

Alkaloids↗
PubMed1978

Serum IgE levels in amoebiasis.

Elevated levels of serum immunoglobulin E (IgE) are found in many parasitic diseases. In order to determine the influence of Entamoeba histolytica on IgE levels of clinically symptomatic patients with intestinal amoebiasis, a controlled study was performed. There was no difference between the serum IgE values from Brazilian patients with amoebiasis and those from age-, race- and sex-matched normal Brazilian controls. Based also on our previous similar studies on giardiasis and Chagas' disease, we conclude that protozoan infections do not elevate serum IgE levels.

Adolescent↗
PubMed1988

[The importance of Entamoeba histolytica in persons returning from the tropics].

Stools from 1000 travellers returning from the tropics were examined for intestinal parasites. The most frequently isolated intestinal pathogens were Giardia lamblia (5%) and E. histolytica (3.6%). For 21 out of 36 E. histolytica isolates iso-enzyme differentiation by starch-gel electrophoresis was possible, yielding a pathogenic pattern in four. This finding correlated closely with clinical symptoms and positive serology, while E. histolytica with non-pathogenic zymodeme should not be considered as a cause of diarrhoea.

Adult↗
PubMed2003

Laboratory diagnosis of amebiasis.

The detection of Entamoeba histolytica, the causative agent of amebiasis, is an important goal of the clinical microbiology laboratory. To assess the scope of E. histolytica infection, it is necessary to utilize accurate diagnostic tools. As more is discovered about the molecular and cell biology of E. histolytica, there is great potential for further understanding the pathogenesis of amebiasis. Molecular biology-based diagnosis may become the technique of choice in the future because establishment of these protozoa in culture is still not a routine clinical laboratory process. In all cases, combination of serologic tests with detection of the parasite (by antigen detection or PCR) offers the best approach to diagnosis, while PCR techniques remain impractical in many developing country settings. The detection of amebic markers in serum in patients with amebic colitis and liver abscess appears promising but is still only a research tool. On the other hand, stool antigen detection tests offer a practical, sensitive, and specific way for the clinical laboratory to detect intestinal E. histolytica. All the current tests suffer from the fact that the antigens detected are denatured by fixation of the stool specimen, limiting testing to fresh or frozen samples.

Animals↗
PubMed2002

The bittersweet interface of parasite and host: lectin-carbohydrate interactions during human invasion by the parasite Entamoeba histolytica.

Entamoeba histolytica, as its name suggests, is an enteric parasite with a remarkable ability to lyse host tissues. However, the interaction of the parasite with the host is more complex than solely destruction and invasion. It is at the host-parasite interface that cell-signaling events commit the parasite to (a) commensal, noninvasive infection, (b) developmental change from trophozoite to cyst, or (c) invasion and potential death of the human host. The molecule central to these processes is an amebic cell surface protein that recognizes the sugars galactose (Gal) and N-acetylgalactosamine (GalNAc) on the surface of host cells. Engagement of the Gal/GalNAc lectin to the host results in cytoskeletal reorganization in the parasite. The parasite cytoskeleton regulates the extracellular adhesive activity of the lectin and recruits to the host-parasite interface factors required for parasite survival within its host. If the parasite lectin attaches to the host mucin glycoproteins lining the intestine, the result is commensal infection. In contrast, attachment of the lectin to a host cell surface glycoprotein leads to lectin-induced host cell calcium transients, caspase activation, and destruction via apoptosis. Finally, trophozoite quorum sensing via the lectin initiates the developmental pathway resulting in encystment. The structure and function of the lectin that controls these divergent cell biologic processes are the subject of this review.

Amebiasis↗
PubMed1975

[Epidemiology of Dientamoeba fragilis Jepps and Dobell, 1918. 3. Further studies on Enterobius transmission through eggs].

In two new attempts to infect human subjects with pin-worms that were infested, at that time, with protozoa Dientamoeba fragilis, presence of these protoza in the intestinal canal was observed in one case for more than 84 days, and in another case for more than 31 days after contamination. The duration of latent periods fixed for Enterobius vermicularis was almost identical (51 and 50 days). New attempts implement and confirm the results of the first successful attempts to transfer the infection (Ockert, 1972b) as well as the hypothesis of the epidemiological interrelation between both parasites (Burrows and Swerdlow 1956).

Amebiasis↗
PubMed1999

Communicable disease in African immigrants in Minneapolis.

BACKGROUND: Despite increasing numbers of African immigrants to the United States, there is a lack of detailed information about their health problems. METHODS: Data on communicable diseases were obtained from the charts of all 102 patients who had emigrated from Africa in the last 5 years and were seen at an urban clinic in Minneapolis, Minn, during the last 7 months of 1997. RESULTS: Eight patients had active tuberculosis, 10 had hepatitis B, 7 trichuriasis, 2 amebiasis, 1 schistosomiasis, 1 ascariasis, 2 human immunodeficiency virus infection, and 1 malaria. All patients tested had antibodies to hepatitis A, 55% to hepatitis B, and 3% to hepatitis C. Characteristics of these patients are described. CONCLUSIONS: Communicable diseases are common in African immigrants, often despite a healthy appearance and prolonged residence in the United States. Careful screening is warranted.

Adult↗
PubMed1999

Asymptomatic amebic colitis in a homosexual man.

We describe case of a 75-yr-old Japanese homosexual man who was diagnosed as having amebic colitis. The present case is unique in that invasive amebiasis has occurred in a homosexual man, because Entamoeba histolytica in homosexual patients is considered to be a nonpathogenic and commensal organism in western countries, and that the patient has not complained of any gastrointestinal symptoms associated with minute colonic lesion of an isolated cecal ulcer. This report indicates that the absence of gastrointestinal symptoms does not rule out invasive amebiasis. Therefore, once the ameba is identified in stool specimens, even in homosexual men, it is important to differentiate pathogenic from nonpathogenic species irrespective of whether the patient is symptomatic, and to treat the patient infected with pathogenic species. By means of this strategy, we can prevent pathogenic ameba from spreading in the community.

Aged↗
PubMedDate not supplied

Expression of the serine rich Entamoeba histolytica protein (SREHP) in the avirulent vaccine strain Salmonella typhi TY2 chi 4297 (delta cya delta crp delta asd): safety and immunogenicity in mice.

Infection by the intestinal protozoan parasite Entamoeba histolytica remains a significant threat to health in much of the world. Here we describe the successful expression of the serine rich Entamoeba histolytica protein (SREHP), a protective antigen of ameba, in an attenuated vaccine strain Salmonella typhi TY2 chi 4297 (delta cya delta crp delta asd). The attenuation of S. typhi TY2 chi 4297 was not altered by expression of the SREHP-maltose binding protein (MBP) fusion protein and mice parenterally vaccinated with S. typhi TY2 chi 4297 expressing SREHP-MBP developed serum anti-amebic and anti-LPS antibodies. S. typhi TY2 chi 4297 expressing SREHP-MBP represents a prototype combination vaccine designed to prevent both amebiasis and typhoid fever.

Animals↗
PubMed1988

Tissue parasitic diseases in Korea.

Parasitic disease is still important subject in the field of infectious diseases in Korea considering it's number and morbidity. Recently there was conspicuous reduction of parasitic disease in terms of soil-transmitted nematodiasis, but parasitism affecting organs other than intestinal tract is still a considerable problem. This survey covers the parasitic diseases cross-sectioned at a pathology laboratory of a referral hospital, trying to elucidate the significance of its relative frequency and also to describe some histopathological changes made by different parasites. Entire pathological materials of parasitic diseases, that were referred, examined and confirmed at the Department of Pathology, Seoul National University Hospital from 1968 to 1987, were used for the study. There was a total of 594 cases of tissue parasitic diseases. This number accounted for 0.33 per cent of total accessions of surgical pathology. There occurred average 30 cases of tissue parasitic disease each year at this Hospital. Protozoal diseases were constituted of 15 cases of amebiasis, 7 cases of leishmaniasis (imported) and 5 cases of Pneumocystis carinii infections. Among helminthic infections cysticercosis was the most common (425 cases), and was followed by paragonimiasis (35 cases), sparganosis (31 cases), clonorchiasis (32 cases) and ascariasis (16 cases). In addition there were 4 cases of anisakiasis, 2 cases of fascioliasis, 2 cases of echinococcosis (imported) and a case of strongyloidiasis and a case of metagonimiasis respectively. It is emphasized that imported parasitic diseases such as leishmaniasis and hydatid disease become steadily found nowadays. Schistosomiasis is another possible imported disease, but not found in this series. And certain cestodiasis particularly cysticercosis and sparganosis should be the subjects of epidemiologic re-evaluation in view of steady occurrence of their morbidity.

Adult↗
PubMed1977

[Diagnostic significance of identification of anti-entamoeba histolytica antibodies (author's transl)].

Examinations were performed with the indirect immunofluorescence test (IFAT) and the indirect haemagglutination test (IHAT). Negative titers (less than 1:5) do not exclude an infection with E. histolytica. Titers up to 1:80 in both reactions are found in patients with negative stool specimens or indicate an asymptomatic infection of the intestinal lumen, an incipient or past symptomatic amoebiasis. IFAT values of 1:160 together with a negative or positive IHAT are also suggestive of the two last-mentioned types of infection. These titers are also found in patients with gastrointestinal disorders of other orgin. IFAT values higher than 1:60 with a positive IHAT are probably due to an invasive amoebiasis. Titres are, however, only diagnostic pointers.

Amebiasis↗
PubMed2005

Microscopic overdiagnosis of intestinal amoebiasis.

To determine the misdiagnosis of intestinal amoebiasis associated to microscopic examination of faeces, 50 stool samples of patients infected with Entamoeba histolytica were collected from different Primary Health Care Centers, hospitals and private laboratories in Ismailia G. The samples were examined using Wheatley's trichrome staining technique to differrentiate E. histolytica E. dispar complex from other non-pathogenic intestinal amoebae and multiplex polymerase chain reaction (PCR). PCR differentiated between the two morphologic identical species (E. histolytica and E. dispar) and had the advantage to save time and resources. E. histolytica was detected in only 5 (10%) samples and in association with E. dispar in 8 (16%) samples. On the other hand, 20 samples (40%) were E. dispar. The other 17 samples were negative. E. coli, E. hartmanni and polymorphs were commonly misdiagnosed as E. histolytica.

Amebiasis↗
PubMed1982

Parasitic bowel disease: three pathogens important in primary care.

A high index of suspicion and careful application of diagnostic methods are essential for accurate diagnosis of parasitic bowel diseases. The varied clinical spectrum of giardiasis, amebiasis, and strongyloidiasis emphasizes the need to consider these pathogens when patients present with gastrointestinal complaints. Giardiasis should be suspected in patients, especially returned travelers, with unexplained increase in stool frequency, particularly with bloating, flatulence, or vague systemic symptoms. Amebiasis must be considered in the differential diagnosis of any patient who presents with persistent diarrhea or signs of inflammatory bowel disease. Unexplained diarrheal illnesses associated with upper abdominal symptoms and eosinophilia should raise suspicion of the presence of strongyloidiasis. These findings in a patient with a compromised immune system or in a candidate for immunosuppressive therapy should prompt a thorough investigation to rule out this parasite, since disseminated strongyloidiasis often is fatal.

Dysentery, Amebic↗
PubMedDate not supplied

Hepatitis and other sexually transmitted diseases in gay men and in lesbians.

The prevalence of most sexually transmitted diseases is disproportionately increased in gay men and paradoxically decreased in lesbian women. The spectrum of diseases seen in gay men include a variety of enteric infections including hepatitis A, shigellosis, salmonellosis, Campylobacter enteritis, amebiasis, giardiasis, and enterobiasis as well as the more common sexually transmitted diseases. Hepatitis B is endemic in gay male populations. The patterns of sexual behavior are the major factors contributing to this unique epidemiology and pathology. Increased sexual activity explained by the unrestrained cultural expectation of maleness, the functional overlap during sex between the genital-urinary and gastrointestinal systems, and anonymous sexual activity are all significant epidemiologic components.

Adult↗
PubMed2002

Biological aspects of a Brazilian strain of Entamoeba dispar.

A strain of Entamoeba dispar was characterized by clinical diagnosis, serological and electrophoretical isoenzyme analysis and by the polymorphism of a 482 bp genomic fragment analysis. The pathogenesis and virulence of this strain was investigated considering the experimental infection in hamster livers in association with the original intestinal microbiota. Liver lesions were observed in hamsters experimentally infected with trophozoites from xenic cultures, but not from the monoxenic cultures. Moreover, clones obtained from re-isolated strain Wil1R1 showed a distinct biological behavior. In fact, animals inoculated with Wil1R1ClB3 showed an intense acute inflammatory reaction with destructive focal hepatic lesions. These lesions were characterized as amebic abscesses. The association between bacteria and ameba has been fairly well studied because it affects the pathogenicity of the amebas and has important therapeutic implications. In this study, we demonstrated that E. dispar in association with the original microbiota is able to produce lesions in hamster liver in spite of its having been considered to be non-pathogenic in the hamster model. Based on these results we suggest that diagnosis of amebiasis needs to be made with more care and that clinical and therapeutical procedures need to be revised.

Animals↗