Implications of False-Negative Clostridium difficile Tests

Patients with false-negative results can be just as sick as those with positive results.

Clostridium difficile infections (CDI) commonly are diagnosed with commercial enzyme immunoassays (EIAs) that identify bacterial toxin, but the tests' sensitivity seldom exceeds 80%. No one has established yet whether this poor performance reflects differences among patients (Are milder infections, for instance, more likely to be missed by EIA?), reflects differences among organisms, or is simply a test characteristic.

Investigators prospectively identified 42 hospitalized patients with diarrhea and negative C. difficile toxin EIAs in whom CDI had been confirmed with a two-step strategy using a more accurate polymerase chain reaction (PCR) assay for the toxin genes. These patients were indistinguishable from 90 patients with positive EIAs ac…

Reviewing Author

Abigail Zuger, MD

Disclosures

Nothing to disclose

Abigail Zuger, MD

Disclosures

Nothing to disclose