title: Comparison of Various Methods in the Diagnosis of Entamoeba histolytica in Stool and Serum Specimens.
abstract: OBJECTIVE
  Entamoeba histolytica is indistinguishable from Entamoeba dispar in direct microscopic examination. A definitive diagnosis of E. histolytica is important in terms of the treatment of the patient and to avoid unnecessary costs. This study's aim is to determine the prevalence of E. histolytica and to make a comparison of the different diagnostic tests in the patients specimens defined as E. histolytica/E. dispar infection.
  
  
  METHODS
  Faecal and serum specimens of 90 patients defined as E. histolytica/E. dispar with microscopy (wet mount examination with 0.85% saline and Lugol's iodine) were examined. Stool samples were examined by trichrome staining for trophozoites and cysts and by immunoassay methods for specific adhesin antigens (Wampole (®) E. histolytica II antigen testing) and for specific serine-rich 30 kD membrane protein (Serazym(®) E. histolytica antigen testing). Anti-E. histolytica antibodies were investigated using a latex slide test and indirect hemagglutination methods in serum specimens.
  
  
  RESULTS
  Presence of E. histolytica was not confirmed in 31.1% cases with trichrome staining, 62.2% of the Wampole antigen test, 64.4%, of the Serazym antigen test, 73.3% of the indirect hemagglutination test and 75.6%. of the latex agglutination. Considering the common results from Wampole and Serazym antigen testing as a reference standard, the specificity/sensitivity is 100/53.85% for trichrome staining, 75.00/98.11% for the latex agglutination test and 78.57/96.77% for the indirect hemagglutination test.
  
  
  CONCLUSIONS
  It has been shown that investigation of E. histolytica in stools by direct wet-smear microscopy alone can cause significant false positive results. To obtain a reliable diagnosis for E. histolytica and to avoid unnecessary treatment for this parasite, at least one more specific assay, particularly an antigen testing and microscopy, is required.
authors.affiliation: Department of Medical Microbiology, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Uslu
authors.affiliation: Department of Medical Microbiology, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Osman
authors.initials: O
authors.lastname: Aktas
authors.affiliation: Department of Medical Microbiology, Atatürk University School of Medicine, Erzurum, Turkey.
authors.forename: Muhammet Hamidullah
authors.initials: MH
authors.lastname: Uyanik
keywords: ELISA; Entamoeba antigens; Entamoeba histolytica/E. dispar; IHA; amoebiasis