Article Figures & Data
Figures
- Fig. 1.
ROC curves representing each ELISA for data from Argentina. The cutoff value for each assay is indicated in the upper right corner of each panel. The AUC is indicative of how well the test performed. A value of 1.0 is perfect, and a value below the diagonal line represents reactivity due to chance. (a) IELISA-ADRI, AUC = 0.983. (b) IELISA-IAEA, AUC = 0.983. (c) CELISA-sLPS, AUC = 0.995. (d) CELISA-OC, AUC = 0.991.
- Fig. 2.
ROC curves representing each ELISA for data from Chile. (a) IELISA-ADRI, AUC = 1.000. (b) IELISA-IAEA, AUC = 0.996. (c) CELISA-sLPS, AUC = 1.000. (d) CELISA-OC, AUC = 1.000. See the Fig. 1 legend for additional explanation of the data.
- Fig. 3.
ROC curves representing each ELISA for data from Colombia. (a) IELISA-ADRI, AUC = 1.000. (b) IELISA-IAEA, AUC = 1.000. (c) CELISA-sLPS, AUC = 0.994. (d) CELISA-OC, AUC = 0.999. See the Fig. 1 legend for additional explanation of the data.
- Fig. 4.
ROC curves representing each ELISA for data from Costa Rica. (a) IELISA-ADRI, AUC = 0.992. (b) IELISA-IAEA, AUC = 0.991. (c) CELISA-sLPS, AUC = 0.974. (d) CELISA-OC, AUC = 0.969. See the Fig. 1 legend for additional explanation of the data.
- Fig. 5.
ROC curves representing each combined ELISA for data from Argentina, Chile, Colombia, and Costa Rica. (a) IELISA-ADRI, AUC = 0.985. (b) IELISA-IAEA, AUC = 0.989. (c) CELISA-sLPS, AUC = 0.995. (d) CELISA-OC, AUC = 0.995. See the Fig. 1legend for additional explanation of the data.
- Fig. 6.
Frequency distribution of ELISA data from Argentina. Open bars, serologically negative samples; closed bars, serologically positive samples. The numbers in each class limit are indicated on top of the bars. (a) IELISA-ADRI. (b) IELISA-IAEA. (c) CELISA-OC. (d) CELISA-sLPS.
- Fig. 7.
Frequency distribution of ELISA data from Chile. (a) IELISA-ADRI. (b) IELISA-IAEA. (c) CELISA-OC. (d) CELISA-sLPS. See the Fig. 6 legend for additional explanation of the data.
- Fig. 8.
Frequency distribution of ELISA data from Colombia. (a) IELISA-ADRI. (b) IELISA-IAEA. (c) CELISA-OC. (d) CELISA-sLPS. See the Fig. 6 legend for additional explanation of the data.
- Fig. 9.
Frequency distribution of ELISA data from Costa Rica. (a) IELISA-ADRI. (b) IELISA-IAEA. (c) CELISA-OC. (d) CELISA-sLPS. See the Fig. 6 legend for additional explanation of the data.
- Fig. 10.
Frequency distribution of combined ELISA data from Argentina, Chile, Colombia, and Costa Rica. (a) IELISA-ADRI. (b) IELISA-IAEA. (c) CELISA-OC. (d) CELISA-sLPS. See the Fig. 6 legend for additional explanation of the data.
Tables
- Table 1.
Comparison of procedures used for the two IELISAs and two CELISAsa
Parameter Assay IAEA-IELISA ADRI-IELISA CELISA-OC CELISA-sLPS Microplate Nunc Polysorb Nunc 69620 Nunc 69620 Nunc 69620 Antigen sLPS sLPS O chain sLPS Concn (μg/ml) 1.0 1.0 2.0 1.0 Buffer 0.05 M CO3 0.05 M CO3 0.05 M CO3 0.05 M CO3 Incubation temp (°C) 4 20 4 (frozen) 20 Incubation time (h) ≥18 ≥18 ≥18 ≥18 Wash buffer 0.002 M PO4, 0.15 M NaCl, 0.05% Tween 20, pH 7.4 0.01 M PO4, 0.15 M NaCl, 0.05% Tween 20, pH 7.2 0.01 M PO4, 0.15 M NaCl, 0.05% Tween 20, pH 7.2 0.01 M PO4, 0.15 M NaCl, 0.05% Tween 20, pH 7.2 No. of wash cycles 3 4 4 4 Serum diluent 0.01 M PBS, 0.05% Tween 20, pH 7.4 Wash buffer plus EDTA-EGTA, pH 6.3 Same as wash buffer Wash buffer plus EDTA-EGTA, pH 6.3 Serum (control/test) Serum dilution 1:200 1:50 1:50 1:20 Incubation temp (°C) 37 20 20 20 Incubation time (min) 60 30 120 30 Agitation Yes No 3 min 3 min Competing antibody NA NA YsT9-HRP M84 Detecting antibody MAb to bovine IgG1-HRP MAb to bovine IgG1-HRP Same as competing GaMIgG-HRP (diluted in wash buffer) Incubation time (min) 60 30 NA 30 Incubation temp (°C) 37 20 NA 20 Agitation Yes No NA No Substrate/chromogen Incubation time (min) 10 10 10 10 Incubation temp (°C) 37 20 20 20 Agitation Yes Yes Yes Yes Wavelength (nm) 405 414 414 414 ↵a Abbreviations: PBS, phosphate-buffered saline; NA, not applicable; HRP, horseradish peroxidase; MAb, monoclonal antibody; IgG1, immunoglobulin G1; GaM, goat anti-mouse IgG-HRP.
- Table 2.
Number of samples tested in each country in each group (not exposed, serologically positive, or vaccinated withB. abortus)
Statusa No. of observations per country and combined Argentina Chile Colombia Costa Rica Combined Negative 215 972 554 872 2,613 Positive 709 692 266 190 1,857 Vaccinate NAb 954 1,110 1,002 3,066 - Table 3.
Comparison of percent positive reactions in each country with actual sensitivity determined in the Canadian study
Country % for assay IELISA-ADRI IELISA-IAEA CELISA-OC CELISA-sLPS Argentina 92.66 97.88 96.90 97.74 Canada 100 NAb NA 100 Chile 98.99 97.11 98.84 100 Colombia 100 100 99.25 98.12 Costa Rica 100 98.42 92.10 93.16 Combineda 96.77 96.28 97.04 97.47 - Table 4.
Comparison of percent negative reactions in each country with specificity determined in the Canadian study
Country % for assay IELISA-ADRI IELISA-IAEA CELISA-OC CELISA-sLPS Argentina 96.28 98.14 98.14 98.14 Canada 99.40 NAb NA 99.90 Chile 99.28 99.59 99.69 99.59 Colombia 99.82 99.82 99.82 97.11 Costa Rica 95.76 94.95 93.35 95.76 Combineda 93.57 97.01 98.05 98.32 - Table 5.
Comparison of reactivity in the ELISAs by animals vaccinated with B. abortus 19 in each country
Country % for assay IELISA-ADRI IELISA-IAEA CELISA-OC CELISA-sLPS Argentina NAd NA NA NA Canada 56.30 NA NA 97.7 Chile 78.82 96.85 94.44 100 Colombia 86.76 87.57 95.50 92.25 Costa Ricab 91.80 94.58 93.12 96.03 Costa Ricac 95.53 97.56 97.56 97.97 Combineda 90.53 94.55 96.08 96.51 - Table 7.
Comparison of agreement among the ELISAs in each country by kappa statisticsa
Assay and country Value for assay IELISA-ADRI IELISA-IAEA CELISA-OC IELISA-IAEA Costa Rica 0.850 Colombia 0.994 Chile 0.963 Argentina 0.824 CELISA-OC Costa Rica 0.756 0.796 Colombia 0.989 0.989 Chile 0.972 0.964 Argentina 0.812 0.910 CELISA-sLPS Costa Rica 0.825 0.793 0.720 Colombia 0.939 0.939 0.939 Chile 0.978 0.965 0.981 Argentina 0.855 0.927 0.931 ↵a A kappa value of 1 is considered to indicate complete agreement.
