TABLE 3.
Estimated disease prevalence and sensitivity and specificity of using serotype-specific qPCR, sputum culture, and UAD to diagnose VTPP by BLCM analysisa
| Serotype-specific pneumococcal DNA load cutoff value (no. of copies/ml) | Disease prevalence | Serotype-specific qPCR |
Quellung reactionb |
UAD |
Youden index of PCR | |||
|---|---|---|---|---|---|---|---|---|
| Sensitivity (%) | Specificity (%) | Sensitivity (%) | Specificity (%) | Sensitivity (%) | Specificity (%) | |||
| ≥103 | 13.0 (8.3–18.8) | 89.9 (71.5–99.7) | 96.1 (92.2–99.4) | 45.2 (26.9–65.1) | 99.5 (98.2–100) | 75.0 (54.1–92.4) | 97.9 (95.0–99.9) | 0.860 |
| ≥104 | 12.9 (8.3–18.5) | 90.2 (71.2–99.7) | 96.9 (93.4–99.7) | 45.8 (27.5–65.8) | 99.5 (98.2–100) | 75.6 (55.4–92.4) | 97.9 (95.1–99.9) | 0.871 |
| ≥105 | 12.1 (7.5–17.8) | 87.7 (63.9–99.7) | 97.5 (94.3–99.8) | 49.0 (28.7–70.2) | 99.5 (98.3–100) | 75.6 (55.1–92.3) | 97.2 (94.0–99.8) | 0.852 |
| ≥106 | 10.7 (6.5–16.0) | 86.0 (61.4–99.6) | 98.7 (96.5–99.9) | 51.4 (30.7–72.6) | 99.1 (97.5–99.9) | 82.0 (62.9–95.6) | 97.0 (93.7–99.9) | 0.847 |
| ≥107 | 9.9 (5.8–15.3) | 84.0 (55.4–99.6) | 99.0 (97.0–100) | 56.0 (32.7–78.2) | 99.1 (97.5–99.9) | 81.7 (62.3–95.7) | 96.3 (92.6–99.6) | 0.830 |
| ≥108 | 7.7 (3.9–13.4) | 78.5 (43.2–99.3) | 98.7 (96.8–99.9) | 61.4 (31.6–87.6) | 98.3 (96.2–99.6) | 91.7 (72.4–99.8) | 95.3 (91.2–99.5) | 0.772 |
| ≥109 | 7.7 (3.4–14.3) | 35.6 (13.8–64.6) | 98.6 (96.7–99.8) | 67.8 (33.6–97.5) | 98.5 (96.3–99.9) | 86.9 (61.7–99.6) | 94.9 (90.4–99.4) | 0.342 |
a
qPCR, quantitative PCR; UAD, serotype-specific urinary antigen detection assay; BLCM, Bayesian latent class model. Values in parentheses are 95% credible intervals.
b
Determined by conventional sputum culture and by use of the Quellung reaction's bacterial load cutoff value of 1.0 × 105 CFU/ml.