Notes of Interest and New Trends

• Which discovery confirmed E. histolytica as a pathogen?A)Study of contaminated waterB) Examination of ameba-infected stoolC) Investigation of soil samplesD) Analysis of insect vectors

  =  Examination of ameba-infected stool
• What is the approximate prevalence of Entamoeba infection in the United States?

  =  4%
• In which regions of the world is the prevalence of Entamoeba infection highest?

  =  Central and South America, Africa, and Asia
• What percentage of E. histolytica cases progress to the invasive stage?

  = 10%
• Which method is NOT commonly used in routine laboratory testing to distinguish between invasive and noninvasive strains of E. histolytica?A)Isoenzyme electrophoresisB) DNA hybridization probe testingC) PCR-based assaysD) Stool ova and parasite examination

  = Stool ova and parasite examination
• What does the World Health Organization (WHO) recommend for diagnosing intestinal E. histolytica infection?

  = E. histolytica-specific tests
• Which findings in stool are considered diagnostic for amebic colitis?A)Quadrinucleated cystsB) Trophozoites lacking red blood cells (RBCs)C) Trophozoites containing ingested erythrocytesD) E. dispar cysts

  = Trophozoites containing ingested erythrocytes
• Which method is NOT used for identifying E. histolytica?A)Immunologic testsB) DNA hybridization probe testingC) PCR-based assaysD) Blood culture

  = Blood culture
• What makes distinguishing between E. histolytica and Entamoeba dispar challenging?

  = Similar morphological appearance
• Which specialized testing methodologies are required for accurate speciation of E. histolytica?A)Stool ova and parasite examinationB) Blood cultureC) DNA probes and electrophoresis techniquesD) PCR-based assays

  = DNA probes and electrophoresis techniques