Table 3.

 Examination of mean Ct values observed for LFD positive and negative clinical specimens

(a) Comparison of H5 HA2 RRT PCR mean Ct values of LFD positive and LFD negatives
Sample type	Mean Ct for LFD negatives* (n)	Mean Ct for LFD positives** (n)	P value
Chicken T	30·6 (14)	20·6 (8)	<0·001
Chicken C	31·3 (12)	22·0 (7)	<0·001
Chicken F	29·6 (4)	20·6 (21)	<0·001
Duck F	22·9 (7)	17·5 (8)	0·0035

(b) H5 HA2 RRT PCR mean Ct values and 95% CIs for Anigen and Quickvue positives
Sample type	Mean Anigen positive	n	Anigen 95% CI	Mean Quickvue positive	n	Quickvue 95% CI
Chicken T	20·6	8	19·5,21·6	20·3	7	19·3,21·4
Chicken C	22·0	7	20·2,23·8	21·5	6	19·9,23·1
Chicken F	20·6	21	19·4,21·8	20·2	14	18·6,21·8
Duck F	17·5	8	16·0,19·0	17·0	5	15·5,18·6

Abbreviations: T, C and F: As in Table 1.

LFD, lateral flow device.

^*Specimens that were negative by both LFDs but positive by H5 HA2 RRT PCR (Ct < 36), i.e. open symbols in 1, 2.

^**Specimens that were positive by at least one LFD, i.e. all the Anigen positives in 1, 2.