Diagnosis of Entamoeba Histolytica Infection

Entamoeba Histolytica is believed to infect a half billion people annually. Approximately 10%of these individuals become symptomatic and develop colitis and liver abscess with a mortality rate ofmore than 40,000 persons each year. The current method of diagnosis is the microscopic visualizationof the organism in fecal specimens. However, this method requires extensive experience, is tedious,and may not be accurate if not performed within minutes of collecting the specimen. In addition, it doesnot distinguish nonpathogenic and pathogenic strains. This project will evaluate the use of monoclonalantibody-based ELISAs designed to detect the presence of the organism in fecal specimens and todistinguish nonpathogenic from pathogenic strains. The ELISAs are based on the use of monoclonalantibodies that bind specifically to the galactose adhesion of the organism. The project will optimize theELISA as a diagnostic test and begin to analyze fecal specimens as well as liver biopsy and serumspecimens for the presence of E.Histolytica antigen. Results will be correlated with microscopy resultsand with zymodeme analysis. The ELISA tests should be useful as diagnostic aids and will make thediagnosis more efficient and cost-effective.