Table 1.
Source and timing of S. pneumoniae surveillance cultures
| Isolate typea | Positive samples, no. (%) | P valueb |
|---|---|---|
| 1st survey | ||
| Total (n = 61) | 13 (21) | <0.05 |
| NP | 1 | |
| ET | 9 | |
| NP+ET | 3 | |
| 2nd survey | ||
| Total (n = 95) | 12 (12) | <0.05 |
| NP | 1 | |
| ET | 9 | |
| NP+ET | 2 | |
| 3rd survey | ||
| Total (n = 108) | 25 (23) | <0.01 |
| NP | 3 | |
| ET | 18 | |
| NP+ET | 4 | |
| All surveys | ||
| Total (n = 264) | >50c (19) | <0.001 |
| NP | 5 | |
| ET | 36 | |
| NP+ET | 9 | |
| Any NP | 14 (5) | |
| Any ET | 45 (17) |
a
NP, isolation in nasopharyngeal sample alone; ET, isolation in endotracheal sample alone; NP+ET, isolation in both samples.
b
McNemar's test, comparing the rates of S. pneumoniae-positive cultures in all ET versus NP cultures.
c
Number of patient-unique isolates: NP, 5; ET, 34; NP+ET, 8.