Table 2.
Kappa test and accuracy calculation and relative sensitivity/specificity values of the lipl32 TaqMan real-time PCR assay using the 16S PCR assay and 16S PCR assay associated with Leptospira identification by DNA sequencing as reference tests.
| Clinical status of the dogs | 16S PCR assay |
16S PCR + Leptospira sp. identification by sequencing |
||||||
|---|---|---|---|---|---|---|---|---|
| Negative | Positive | Total | Negative | Positive | Total | |||
| Symptomatic | TaqMan real-time assay | Negative | 19 | 5 | 24 | 22 | 2 | 24 |
| Positive | 0 | 11 | 11 | 0 | 11 | 11 | ||
| Total | 19 | 16 | 35 | 22 | 13 | 35 | ||
| Sp = 100% (79.1–100%) Se = 68.8% (41.5–87.9%) |
Sp = 100% (81.5–100%) Se = 84.6% (53.7–97.3%) |
|||||||
| kappa = 0.705 (0.48–0.93); accuracy = 85.7% (68.9–94.6%) | kappa = 0.874 (0.70–1); accuracy = 94.3% (79.5–99.0%) | |||||||
| Negative | Positive | Total | Negative | Positive | Total | |||
| Asymptomatic | TaqMan real-time assay | Negative | 89 | 15 | 104 | 104 | 0 | 104 |
| Positive | 0 | 12 | 12 | 0 | 12 | 12 | ||
| Total | 89 | 27 | 116 | 104 | 12 | 116 | ||
| Sp = 100% (94.8–100%) Se = 44.4% (26.0–64.4%) |
Sp = 100% (95.6–100%) Se = 100% (69.9–100%) |
|||||||
| kappa = 0.551 (0.36–0.74); accuracy = 87.1% (79.2–92.3%) | kappa = 1.0 (1.0–1.0); accuracy = 100% (96.0–100%) | |||||||
| Negative | Positive | Total | Negative | Positive | Total | |||
| Total | TaqMan real-time assay | Negative | 108 | 20 | 128 | 127 | 2 | 129 |
| Positive | 0 | 23 | 23 | 0 | 22 | 22 | ||
| Total | 108 | 43 | 151 | 127 | 24 | 151 | ||
| Sp = 100% (95.7–100%) Se = 53.4% (37.8–68.5%) |
Sp = 100% (96.3–100%) Se = 91.6% (71.5–98.5%) |
|||||||
| kappa = 0.593 (0.48–0.76) accuracy = 86.7% (80.0–91.5%) |
kappa = 0.948 (0.88–1.0) accuracy = 98.7% (94.8–100) |
|||||||
Sp: relative specificity; Se: relative sensitivity.