Table 2.

Results from single samples from past infection

	Paris-Clamart	Bologna
Samples tested	57	50
Low avidity	0	4
Gray-zone	6	6
High avidity	51	40
Specificitya	100.00 %	90.90 %
95 % CIa	93.02–100.00	78.33–97.47
Specificityb	89.50 %	80.00 %
95 % CIb	78.48–96.04	66.28–89.97

^aResults falling within the gray-zone were excluded from the analysis

^bResults falling within the gray-zone were considered as low avidity for the analysis