TABLE 3.

Comparison of commercial C. difficile detection assays with results of cytotoxigenic culture

AssayNo. of samples with the following assay result:Cytotoxigenic culture resultNo. of samples testedSensitivity (%) (95% CI)aSpecificity (%) (95% CI)a
PositiveNegativeEquivocalInvalid
Cytotoxin test1081700Positive12586.4 (79.1-91.9)99.2 (97.9-99.8)
447100Negative475
Premier toxin A+B1012400Positive12580.8 (72.3-87.3)97.5(95.5-98.6)
1246300Negative475
GA Clostridium difficile antigen863900Positive12568.8 (59.9-76.8)91.4 (88.4-93.7)
4145400Negative475
Ridascreen toxin A/B755000Positive12560.0 (50.9-68.7)95.6 (93.2-97.2)
2043410Negative475
Techlab toxin A/B II1002500Positive12580.0 (71.9-86.6)96.0 (93.7-97.5)
1945600Negative475
Remel ProSpecT1022300Positive12581.6 (73.7-87.9)93.3 (90.6-95.4)
3244300Negative475
Vidas C. difficile Tox A/B1001690Positive12580.0 (71.9-86.6)97.3 (95.2-98.5)
2462110Negative475
Remel Xpect863180Positive12568.8 (59.9-76.8)99.4 (98.2-99.9)
347200Negative475
Techlab Tox A/B Quik Chek933200Positive12574.4 (65.8-81.78)98.9 (97.6-99.7)
347011Negative475
Premier Immunocard A + B8629010Positive12568.8 (59.9-76.8)93.0 (90.4-95.2)
2442031Negative475
Techlab C. diff Chek-60921300Positive10587.6 (72.4-93.0)94.3 (91.7-96.2)
2643300Negative459
BD GeneOhm C. difficile921101Positive10488.5 (80.3-93.6)95.4 (92.9-97.0)
1643305Negative454
  • a The sensitivity and specificity of the assays compared to the gold standard cytotoxigenic culture results are shown. The sensitivity and specificity are given as percentages, and the 95% confidence interval (95% CI) values are shown in parentheses.