TABLE 3.
Comparison of the Smart GBS and Xpert GBS LB assays to the broth-enriched culture
| Test | No. of specimens | No. of specimens with result of: |
Sensitivity (% [CI]) | Specificity (% [CI]) | |||
|---|---|---|---|---|---|---|---|
| TP | TN | FP | FN | ||||
| Smart GBS | 813 | 184 | 595 | 28a | 6b | 96.8 (93–99) | 95.5 (94–97) |
| Xpert GBS LB | 826 | 189 | 587 | 48c | 2d | 99.0 (96–100) | 92.4 (90–94) |
Twenty-four of 26 specimens were confirmed as positive for GBS and 2/26 as negative for GBS following discrepant analysis by nucleic acid sequencing. Two specimens were not available for discrepant analysis.
Two of 3 specimens were confirmed as positive for GBS and 1/3 as negative following discrepant analysis by nucleic acid sequencing. The remaining 3 were not available for discrepant analysis.
Forty-two of 47 specimens were confirmed as positive for GBS and 5/47 as negative following discrepant analysis by nucleic acid sequencing. Additionally, 24/47 were positive when tested with the Smart GBS assay. One specimen was not available for discrepant analysis.
Both specimens were confirmed as negative for GBS following discrepant analysis by nucleic acid sequencing.