Some literature in recent years has suggested that assays for GDH, an enzyme produced by C. difficile, could provide a more sensitive means of screening for C. difficile.
Published studies have indicated that toxin immunoassays, by themselves, may not provide adequate sensitivity of detection. Several investigators have examined the utilization of a two-step algorithm. This first step is an enzyme immunoassay for the GDH antigen.
A negative result for GDH has been associated with a high value for prediction of a true negative result; however, a positive result is not necessarily associated with a toxin producing strain. A second assay on positive samples for detection of toxin production is required in these algorithms.