Table 3. Comparison of DBP-IgG Western blot and hexon Western blot.

	Hexon Western blot
DBP-IgG Western blot	Positive	Negative	Total
Positive	100	1	101
Negative	1	2	3
Total	101	3	104

χ²  =  44.9, P<0.01. The sensitivity and specificity of the DBP Western blot versus the hexon Western blot was 99% and 66.7%, respectively. Calculation formula: sensitivity  =  TP/(TP+FN), specificity  =  TN/(FP+TN), where TP is the number of true positives, FN is the number of false negatives, FP is the number of false positives, and TN is the number of true negatives [36].