Table 123-1 Relative Sensitivity and Specificity of Diagnostic Tests for Clostridium difficile–Associated Disease (CDAD) Type of Test Relative Sensitivitya Relative Specificitya Comment Stool for C. difficile culture ++++ +++ Most sensitive test; specificity is ++++ if the C. difficile isolate tests positive for toxin; with clinical data, is diagnostic of CDAD Cell culture +++ ++++ With clinical data, is diagnostic of CDAD; highly specific but not as sensitive as stool culture cytotoxin test on stool Enzyme immunoassay for +++ ++ to +++ With clinical data, is diagnostic of CDAD; rapid results, but not as sensitive as stool culture or cell culture cytotoxin test toxin A or toxins A and B in stool Latex test for C. difficile antigen in stool ++ +++ Detects glutamate dehydrogenase found in.
