TABLE 4.
Overall test performance (AUC) after ROC analysis and resulting sensitivities of quantitative tests when used on three different Brucella-free populations as negative controlsa
| Test | Antigen | Results for Brucella-free populations with characteristic indicated
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Not exposed to Y. enterocolitica O:9
|
Experimentally infected with Y. enterocolitica O:9
|
Member of FPSR herds
|
||||||||
| AUC (95% CI) | Cutoff | Se (95% CI) | AUC (95% CI) | Cutoff | Se (95% CI) | AUC (95% CI) | Cutoff | Se (95% CI) | ||
| Indirect ELISA | B. melitensis crude S-LPS | 1 (0.988-1) | >31.12 | 100 (98-100) | 1 (0.983-1) | >79.57 | 100 (98-100) | 1 (0.988-1) | >93.1 | 98.9 (96.2-99.8) |
| B. melitensis NH | 1 (0.988-1) | >35.29 | 100 (98-100) | 0.999 (0.98-1) | >90.6 | 97.9 (94.7-99.4) | 0.999 (0.987-1) | >94.7 | 96.3 (92.5-98.5) | |
| B. abortus PS | 1 (0.988-1) | >23.07 | 100 (98-100) | 0.911 (0.865-0.945) | >100.74 | 30.7 (24.2-37.8) | 0.987 (0.968-0.996) | >102.5 | 19 (13.7-25.4) | |
| B. suis S-LPS | 1 (0.988-1) | >15.87 | 100 (98-100) | 0.983 (0.955-0.995) | >98.6 | 71.4 (64.4-77.7) | 0.999 (0.987-1) | >94.7 | 97.9 (94.7-99.4) | |
| E. hermanni S-LPS | 0.988 (0.95-0.998) | >75.04 | 97.7 (91.8-99.7) | 0.997 (0.959-1) | >143.78 | 0 (0-4.2) | 0.712 (0.62-0.794) | >141.1 | 0 (0-4.2) | |
| B. ovis R-LPS-Omps | 0.994 (0.978-0.999) | >37.45 | 82.5 (76.4-87.7) | 0.714 (0.649-0.773) | >74.02 | 42.9 (35.7-50.2) | 0.827 (0.78-0.867) | >82.9 | 39.2 (32.2-46.5) | |
| B. abortus per R-LPS | 0.997 (0.983-0.999) | >38.47 | 93 (88.4-96.2) | 0.484 (0.415-0.553) | >85.04 | 8.6 (5-13.5) | 0.678 (0.623-0.729) | >114.34 | 1.1 (0.2-3.8) | |
| B. abortus BP26 | 0.973 (0.949-0.988) | >64.58 | 74.7 (68.1-80.6) | 0.859 (0.806-0.901) | >66.96 | 70.7 (63.8-76.9) | 0.96 (0.932-0.979) | >67.6 | 70.7 (63.8-76.9) | |
| B. melitensis 115 cytosol | 0.999 (0.985-1) | >62.42 | 93.1 (88.5-96.3) | 0.9 (0.852-0.936) | >89.9 | 69.3 (62.2-75.8) | 0.941 (0.908-0.964) | >88.5 | 71.4 (64.4-77.7) | |
| Chaotropic ELISA | ||||||||||
| 1 M KSCN | B. melitensis crude S-LPS | 1 (0.988-1) | >12.62 | 100 (98-100) | 0.999 (0.981-1) | >19.35 | 99.5 (97.1-99.9) | 0.999 (0.987-1) | >39.9 | 95.8 (91.8-98.1) |
| 2 M KSCN | B. melitensis crude S-LPS | 0.994 (0.977-0.999) | >25.79 | 97.9 (94.7-99.4) | 0.996 (0.975-0.999) | >19.65 | 98.9 (96.2-99.8) | 0.994 (0.977-0.999) | >52.5 | 85.7 (79.9-90.4) |
| 3 M KSCN | B. melitensis crude S-LPS | 0.961 (0.932-0.98) | >21.22 | 88.9 (83.5-93) | 0.978 (0.949-0.993) | >13.44 | 95.8 (91.8-98.1) | 0.973 (0.948-0.988) | 21.2 | 88.9 (83.5-93) |
| Competitive ELISA | B. abortus S-LPS | 0.977 (0.951-0.991) | >35.73 | 84.4 (78.3-89.4) | 0.930 (0.886-0.961) | >45.23 | 75.0 (68.0-81.1) | 0.932 (0.897-0.957) | >57.2 | 61.7 (54.1-68.8) |
a
Cutoffs were selected to result in 100% specificity for each independent Brucella-free population. Se, sensitivity (%).