Table 1.

Sensitivity (with 95% lower and upper confidence limits) of different mortality thresholds to signal flocks infected with H7N7 highly pathogenic avian influenza.

Mortality trigger	Sensitivity % (detected/total)	95% LCL – UCL
Mortality % >0.08/0.13	95.3% (105/110)	89.8–98.0
Ratio >2.9	97.3% (107/110)	92.3–99.1
Mortality % ≥0.25% (1 day)	73.6% (81/110)	64.7–81.0
Mortality % ≥0.5% (1 day)	73.6% (81/110)	64.7–81.0

Data from 110 infected layer flocks during the 2003 epidemic in the Netherlands was used for this assessment.