Multisite Performance Evaluation of an Enzyme-Linked Immunosorbent Assay for Detection of Giardia, Cryptosporidium, and Entamoeba histolyticaAntigens in Human Stool

ABSTRACTA novel fecal antigen detection assay for fresh and frozen human samples that detects but does not differentiate Giardiaspp, Cryptosporidiumspp, and Entamoeba histolytica, the Tri-Combo parasite screen, was compared to three established enzyme-linked immunosorbent assays (ELISAs) at three international sites. It exhibited 97.9% sensitivity and 97.0% specificity, with positive and negative predictive values of 93.4% and 99.1%, respectively. The Tri-Combo test proved a reliable means to limit the use of individual parasite ELISAs to positive samples.