Testing methods for Clostridium difficile-associated diarrhea
| Test | Positive predictive valuea | Negative predictive valuea | Cost11 | Turnaround time11 |
|---|---|---|---|---|
| Toxigenic culture | 94%9 | 98%9 | $10–30 | 24–48 hours, up to 9 days |
| C difficile cytotoxin neutralization assay | 93%9 | 97%9 | $15–25 | 24–48 hours |
| EIA for GDH | 73%9 | 97%9 | $15–20 | 15 minutes |
| EIA for toxins A and B | 70%10 | 92%10 | $15–20 | 15 minutes |
| Nucleic acid amplification tests | 84%10 | 99%10 | $25–30 | 2.5 hours |
↵a Positive predictive value and negative predicted value may vary based on specific assay and local prevalence
EIA = enzyme immunoassay, GDH = glutamate dehydrogenase