Contemporary approaches for the laboratory diagnosis of Clostridium difficile infections

Since its recognition 35 years ago as a major cause of diarrheal disease in the industrialized world, the laboratory diagnosis of Clostridium difficile infections (CDI) has been in constant evolution. Currently, two approaches are recommended: a multi-step algorithm using glutamate dehydrogenase (GDH) detection as a screening test and a method to detect either C. difficile toxins or toxigenic C. difficile organisms as a confirmatory test for GDH-positive specimens. One potential algorithm uses the detection of both toxin and organisms in a stepwise manner. The second approach is the use of a nucleic acid amplification test to detect toxigenic organisms. Both methods have been proven to be sensitive and to have acceptable turnaround times. Questions still remain about which of these two approaches are optimal for establishing the diagnosis of CDI.