AN AUTOMATED CHEMILUMINESCENCE IMMUNOASSAY FOR DETECTION OF GIARDIA DUODENALIS ANTIGENS FROM CANINE SPECIMENS

This study reports the automation and evaluation of the Giardia chemiluminescence assay (GCA), an assay designed to detect infectious Giardia duodenalis present in veterinary stool samples. The automated GCA (auto-GCA) enabled stringent step pacing and significant reduction of hands-on time for the assay operator, and it yielded assay performance comparable with the manual assay in activity profiles, dose-dependent ranges and half-maximal effective concentrations. In a study with clinic-collected canine stool specimens, 115 samples analyzed by auto-GCA had a sensitivity of 95.1% and a specificity of 90.7% compared with a standard G. duodenalis ELISA. In another study, 81% of 62 canine samples that were identified as borderline by ELISA were classified definitively as positive or negative for G. duodenalis by auto-GCA. To our best knowledge, the auto-GCA is the first system in the parasite diagnosis area to use full automation and chemiluminescence, and it is expected to improve work quality for individual researchers and for laboratories.