Detection of Giardia lamblia and Entamoeba histolytica in stool samples bytwo enzyme immunoassays

Two commercially produced enzyme immunoassays (EIAs) to detect antigens of Giardia lamblia and Entamoeba histolytica in stool specimens were evaluated . A total of 276 stool specimens were collected from patients who presented with various medical complaints in the outpatient clinic of the Department of Infectious Diseases and Tropical Medicine, University of Munich. Every specimen was examined by conventional microscopy and tested by both EIA kit s. When microscopy was used as the reference standard, the EIA kit detectin g Giardia lamblia showed a sensitivity of 100% and a specificity of 99.6%. The EIA kit detecting Entamoeba histolytica had a sensitivity of 81.8% and a specificity of 99.2%. Both tests showed no cross-reactivity with other in testinal protozoa. Antigen detection by EIA has the potential to become a v aluable tool capable of making stool diagnostics more effective, although i t should not be considered as a replacement for microscopic examination, si nce other potential pathogens could otherwise escape detection.