Diagnostic tests for Clostridioides difficile
| Test | Characteristics | Sensitivity, specificity |
|---|---|---|
| Organism detection assays | ||
| Nucleic acid amplification tests (eg, polymerase chain reaction) | Detects toxin gene (ie, organism) but not toxins | High sensitivity Low to moderate specificity |
| Glutamate dehydrogenase | C difficile common antigen | High sensitivity Low specificity |
| Toxigenic C difficile culture | Growth of C difficile organism Testing not readily available Slow turnaround time | High sensitivity Low specificity |
| Toxin detection assays | ||
| Enzyme immunoassay | Detects free toxins | Low sensitivity Moderate specificity |
| Cell culture cytotoxicity neutralization assay | Detects free toxins Lacks standardization Slow turnaround time | High sensitivity High specificity, if optimized |
Information from McDonald et al, reference 2.