Table 5.
Diagnostic parameters of algorithms with IgG component only
| EM sera (n = 228) | |||||
| MTTT-permissive | MTTT-permissive IgG-only | ||||
| No. of true positive (sensitivity %) | 95%-CI | No. of true positive (sensitivity %) | 95%-CI | ||
| Enz1/C6 | 173 (75.9) | 69.8–81.3 | Enz1-IgG/C6 | 101 (44.3)* | 37.7–51.0 |
| Enz2/C6 | 177 (77.6) | 71.7–82.9 | Enz2-IgG/C6 | 166 (72.8)* | 66.5–78.5 |
| Lia/C6 | 166 (72.8) | 66.5–78.5 | Lia-IgG/C6 | 156 (68.4)* | 62.0–74.4 |
| PopC sera (n = 231) | |||||
| MTTT-permissive | MTTT-permissive IgG-only | ||||
| No. of true negative (specificity %) | 95%-CI | No. of true negative (specificity %) | 95%-CI | ||
| Enz1/C6 | 221 (95.7) | 92.2–97.9 | Enz1-IgG/C6 | 221 (95.7) | 92.2–97.9 |
| Enz2/C6 | 222 (96.1) | 92.7–98.2 | Enz2-IgG/C6 | 222 (96.1) | 92.7–98.2 |
| Lia/C6 | 220 (95.2) | 91.6–97.6 | Lia-IgG/C6 | 221 (95.7) | 92.2–97.9 |
| CRC sera (n = 50) | |||||
| MTTT-permissive | MTTT-permissive IgG-only | ||||
| No. of true negative (specificity %) | 95%-CI | No. of true negative (specificity %) | 95%-CI | ||
| Enz1/C6 | 41 (82.0) | 68.6–91.4 | Enz1-IgG/C6 | 48 (96.0)* | 86.3–99.5 |
| Enz2/C6 | 41 (82.0) | 68.6–91.4 | Enz2-IgG/C6 | 48 (96.0)* | 86.3–99.5 |
| Lia/C6 | 42 (84.0) | 70.9–92.8 | Lia-IgG/C6 | 47 (94.0)* | 83.5–98.8 |
*p < 0.05 as compared with equivalent MTTT-permissive (one-sample t test)
95%-CI, 95% confidence interval; MTTT, modified two-tier testing; Enz1, Enzygnost-1; Enz2, Enzygnost-2; Lia, Liaison; C6, C6-ELISA; EM, erythema migrans; PopC, population control; CRC, cross-reactive control; permissive, counting equivocal EIA results as positive; IgG only, using only the IgG component of the first-tier assay