TABLE 1.
Performance characteristics of culture, direct carbohydrate antigen test, and DNA probe testa
| Testb | Site | % Sensitivity | % Specificity | % PPV | % NPV |
|---|---|---|---|---|---|
| Rapid Strep* | Throat | 80.6 (62.5-92.5) | 100 (85.1-100) | 100 (86.3-100) | 78.6 (59.0-91.7) |
| DNA probe† | Throat | 93.3 (77.9-99.2) | 95.7 (78.1-99.9) | 96.6 (82.2-99.9) | 91.7 (73.0-98.9) |
| Rapid Strep* | Mouth | 19.4 (7.5-37.5) | 100 (84.6-100) | 100 (54.1-100) | 46.8 (32.1-61.9) |
| DNA probe* | Mouth | 41.9 (23.9-60.9) | 100 (84.6-100) | 100 (75.3-100) | 55.0 (38.5-70.7) |
| Culture* | Mouth | 80.6 (62.5-92.5) | 100 (84.6-100) | 100 (86.3-100) | 78.6 (59.0-91.7) |
a
Specimens were obtained from the posterior pharynges and mouths of 53 study subjects. Values shown are means (95% confidence intervals). PPV, positive predictive value; NPV, negative predictive value. A P value of <0.001 was determined for all pairwise comparisons of sensitivities of the different streptococcal tests performed on specimens obtained from the mouth versus the posterior pharynx/throat.
b
*, gold standard reference is positive culture or DNA probe of posterior pharynx/tonsils. †, gold standard reference is positive culture of the posterior pharynx/tonsils.