TABLE 2.
Performance of DC and EIA-GDH and EIA-TcdA/TcdB, LMIA-PCR and real-time PCR, compared to EC and TEC, respectivelya
| Comparator test | Parameterb | Performance (95% confidence interval) |
||||
|---|---|---|---|---|---|---|
| DC | EIA-GDH | EIA-TcdA/TcdB | RT-PCR | LMIA-PCR | ||
| EC | % sensitivity | 91.9 (82.2–97.3) | 41.9 (29.5–55.2) | |||
| % specificity | 100.0 (96.2–100.0) | 92.6 (85.4–97.0) | ||||
| % PPV | 100.0 (93.7–100.0) | 78.8 (61.1–91.0) | ||||
| % NPV | 95.0 (88.7–98.3) | 71.0 (62.1–78.8) | ||||
| TEC | % sensitivity | 5.6 (0.8–18.7) | 42.9 (26.3–60.6) | 25.0 (12.2–42.2) | ||
| % specificity | 99.2 (95.5–99.9) | 96.7 (91.7–99.1) | 95.9 (90.6–98.6) | |||
| % PPV | 66.7 (11.6–94.5) | 78.9 (54.4–93.8) | 64.3 (35.2–87.1) | |||
| % NPV | 77.9 (70.5–84.2) | 85.4 (78.4–90.9) | 81.1 (73.7–87.2) | |||
a
DC, direct culture (C. difficile chromID agar; bioMérieux); EIA-TcdA/TcdB, enzyme immunoassay (EIA) for TcdA and TcdB (C. diff Quik Chek; Alere); EIA-GDH, EIA for C. difficile glutamate dehydrogenase (GDH) (C. diff Quik Chek; Alere); real-time PCR, real-time PCR for tcdB (GeneOhm Cdiff; Becton Dickinson); LMIA-PCR, loop-mediated isothermal amplification-PCR for tcdA (illumigene C. difficile; Meridian); EC, enrichment culture; TEC, enrichment culture with PCR for toxin genes.
b
PPV, positive predictive value; NPV, negative predictive value.