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. 2012 May 22;7(5):e37327. doi: 10.1371/journal.pone.0037327

Table 4. Determined assay performance.

Parasite species (n) Sensitivity [95% CI] (n) Specificity [95% CI] Kappa [95% CI] Female worms
Teladorsagia circumcincta (20/21) 95.2% [76.2–99.9] (7/9) 77.8% [40.0–97.2] 0.75 [0.5–1.0] ≥60
Trichostrongylus spp. (11/16) 68.8%a [41.3–89.0] (13/14) 92.9% [66.1–99.8] 0.61 [03–0.9] ≥20
Trichostrongylus spp. (11/12) 91.7% [61.5–99.8] (17/18) 94.4% [72.7–99.9] 0.86 [0.7–1.0] ≥100
Chabertia ovina (8/8) 100% [63.1–100] (22/22) 100% [84.6–100] 1.00 (1.0–1.0) ≥1
Oesophagostomum venulosum (0/0) N/Ab N/A (30/30) 100% [88.4–100] N/A N/A N/A
Haemonchus contortus (0/0) N/A N/A (30/30) 100% [88.4–100] N/A N/A N/A
Total (22/22) 100% [84.6–100] (7/8) 87.5 [47.4–99.7] 0.91 [0.7–1.0] N/A

PCR assay performance and direct comparison with total worm count results. Shown are the calculated diagnostic sensitivity and specificity of the PCR, the number of cases identified as positive or negative in comparison to total worm counts (n), calculated Kappa values and their 95% confidence interval (CI). Also shown are the minimum number of species females as detected by PCR and the total diagnostic performance (the ability to detect infections involving the presence of any females of the target species by PCR).

a

all PCR false-negative test results related to TWC results of <100 female worms per sheep.

b

No data available.