Table 2.
Cross-classification of results obtained by invA-based PCR and ISO protocol alone or after second culture of the 33 discrepant samples from PA and PBa
| PCR result | No. of samples |
Total | |||
|---|---|---|---|---|---|
| PA |
PB |
||||
| ISO+ | ISO− | ISO+ | ISO− | ||
| Positive | 137 (155)b | 27 (9) | 16 (17) | 6 (5) | 186 |
| Negative | 22 | 146 | 5 | 287 | 460 |
| Total | 159 (177) | 173 (155) | 21 (22) | 293 (292) | 646 |
a
Discrepant samples were PCR+ and ISO−. The kappa statistic value considering exclusively the ISO results was 0.77 (95% CI, 0.72, 0.83).
b
Values in parentheses represent the number of samples with the indicated result after a second culture.