TABLE 1.
Performance of vaginal swab specimens for detection of C. trachomatis and N. gonorrhoeae
| Organism and test | Swab specimen | No. of specimens with positive result | No. of specimens with false-positive results | Sensitivitya | Specificityb | Positive predictive valuea | Negative predictive valued |
|---|---|---|---|---|---|---|---|
| C. trachomatise | |||||||
| PCR | Endocervical | 33 | 2 | 33/37 (89.2) | 416/418 (99.5) | 33/35 (94.3) | 416/420 (99.0) |
| SDA | Vaginal | 34 | 1 | 34/37 (91.9) | 417/418 (99.8) | 34/35 (97.1) | 417/420 (99.3) |
| SDA | Endocervical | 34 | 2 | 34/37 (91.9) | 416/418 (99.5) | 34/36 (94.4) | 416/419 (99.3) |
| N. gonorrhoeaef | |||||||
| Culture | Endocervical | 30 | 0 | 30/39 (76.9) | 416/416 (100) | 30/30 (100) | 416/425 (97.9) |
| SDA | Vaginal | 39 | 1 | 39/39 (100) | 415/416 (99.8) | 39/40 (97.5) | 416/416 (100) |
| SDA | Endocervical | 39 | 0 | 39/39 (100) | 416/416 (100) | 39/39 (100) | 415/415 (100) |
The data represent the number of specimens with a positive result/total number of true-positive specimens (percent).
The data represent the number of specimens with a negative result/total number of negative specimens (percent).
The data represent the number of specimens with a correct positive result/total number of positive specimens tested (percent).
The data represent the number of specimens with a correct negative result/total number of negative specimens tested (percent).
A true-positive result was defined as positive results by two molecular tests (PCR and SDA, PCR and LCR, or LCR and SDA).
A true-positive result was defined as a positive result by culture or positive results by two molecular tests (SDA and LCR).