Diagnostic tests for Clostridioides difficile

TestCharacteristicsSensitivity, specificity
Organism detection assays
Nucleic acid amplification tests (eg, polymerase chain reaction)Detects toxin gene (ie, organism) but not toxinsHigh sensitivity
Low to moderate specificity
Glutamate dehydrogenaseC difficile common antigenHigh sensitivity
Low specificity
Toxigenic C difficile cultureGrowth of C difficile organism
Testing not readily available
Slow turnaround time
High sensitivity
Low specificity
Toxin detection assays
Enzyme immunoassayDetects free toxinsLow sensitivity
Moderate specificity
Cell culture cytotoxicity neutralization assayDetects free toxins
Lacks standardization
Slow turnaround time
High sensitivity
High specificity, if optimized
  • Information from McDonald et al, reference 2.