TABLE 1.
Growth of Bordetella pertussis from PCR-positive samples by CT value and delay from sampling to plating
| CT valuea | No. of samples culture positive/total (%) |
||
|---|---|---|---|
| Overall | Delay to cultureb: |
||
| <5 days | ≥5 days | ||
| <15 | 6/7 (86) | 5/5 (100) | 1/2 (50) |
| 15–19 | 13/14 (93) | 10/10 (100) | 3/4 (75) |
| 20–24 | 13/23 (56.5) | 11/18 (61) | 2/5 (40) |
| 25–29 | 9/37 (24) | 8/27 (30) | 1/10 (10) |
| 30–34 | 4/48 (8.3) | 1/30 (3.3) | 3/18 (17) |
| ≥35 | 0/94 (0) | 0/67 (0) | 0/27 (0) |
| Total | 45/223 (20) | 35/157 (22) | 10/66 (15) |
a
CT, threshold cycle.
b
Shown is the number of days from nasopharyngeal sampling to plating onto charcoal agar.